/* ============================================================
   SMART CLASSROOM - PREMIUM MODERN LIGHT UX/UI DESIGN SYSTEM
   Theme: Minimalist, Intuitive, Crisp Light Aesthetic
   Typography: Inter & Plus Jakarta Sans
   Designed for Multi-Classroom Management (2+ Rooms)
   ============================================================ */

:root {
    /* Core Light Palette */
    --bg-main: #f8fafc;           /* Airy slate-50 background */
    --bg-secondary: #ffffff;      /* Pure white card backgrounds */
    --card-bg: #ffffff;
    --card-bg-hover: #f1f5f9;
    --card-border: #e2e8f0;      /* Subtle slate-200 border */
    --card-border-hover: #cbd5e1;
    --card-glow: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
    --card-glow-elevated: 0 12px 32px -4px rgba(15, 23, 42, 0.08), 0 4px 12px -2px rgba(15, 23, 42, 0.04);

    /* Text Colors (High Contrast & Clear Hierarchy) */
    --text-pure: #0f172a;         /* Deep slate-900 for headings */
    --text-main: #1e293b;         /* Slate-800 for body */
    --text-dim: #475569;          /* Slate-600 for subtext */
    --text-muted: #64748b;        /* Slate-500 for captions & labels */

    /* Brand & Accent Colors */
    --primary: #2563eb;           /* Modern vibrant Royal Blue */
    --primary-rgb: 37, 99, 235;
    --primary-dark: #1d4ed8;
    --primary-light: #eff6ff;
    --accent: #7c3aed;            /* Electric Violet */
    --accent-rgb: 124, 58, 237;
    --accent-light: #f5f3ff;

    /* Semantic States */
    --success: #10b981;           /* Emerald Green */
    --success-rgb: 16, 185, 129;
    --success-light: #ecfdf5;
    --warning: #f59e0b;           /* Warm Amber */
    --warning-rgb: 245, 158, 11;
    --warning-light: #fffbeb;
    --danger: #ef4444;            /* Rose Red */
    --danger-rgb: 239, 68, 68;
    --danger-light: #fef2f2;
    --info: #0284c7;              /* Sky Blue */
    --info-light: #f0f9ff;

    /* Multi-Room Color Identifiers */
    --room-1-color: #2563eb;
    --room-1-bg: #eff6ff;
    --room-2-color: #059669;
    --room-2-bg: #ecfdf5;
    --room-3-color: #7c3aed;
    --room-3-bg: #f5f3ff;
    --room-4-color: #d97706;
    --room-4-bg: #fffbeb;

    /* Layout Tokens */
    --sidebar-width: 270px;
    --topbar-height: 72px;
    --radius-xl: 18px;
    --radius-lg: 14px;
    --radius-md: 10px;
    --radius-sm: 6px;
    --transition: all 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================================
   BASE RESET & GLOBAL TYPOGRAPHY
   ============================================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 14px;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Plus Jakarta Sans', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    min-height: 100vh;
    line-height: 1.5;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Subtle background accent gradients */
body::before {
    content: '';
    position: fixed;
    top: -120px;
    left: 15%;
    width: 550px;
    height: 550px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.04) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

body::after {
    content: '';
    position: fixed;
    bottom: -100px;
    right: 10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(16, 185, 129, 0.035) 0%, transparent 70%);
    pointer-events: none;
    z-index: 0;
}

button, input, select, textarea {
    font-family: inherit;
    color: inherit;
}

button {
    cursor: pointer;
    border: none;
    background: none;
}

a {
    color: inherit;
    text-decoration: none;
}

.app {
    display: flex;
    min-height: 100vh;
    position: relative;
    z-index: 1;
}

/* ============================================================
   SIDEBAR - NAVIGATION & ROOM QUICK SELECTOR
   ============================================================ */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: #ffffff;
    border-right: 1px solid var(--card-border);
    display: flex;
    flex-direction: column;
    padding: 22px 18px;
    z-index: 100;
    transition: var(--transition);
    box-shadow: 2px 0 12px rgba(15, 23, 42, 0.02);
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 4px 6px 20px;
    border-bottom: 1px solid var(--card-border);
    margin-bottom: 20px;
}

.brand-icon {
    width: 42px;
    height: 42px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: #ffffff;
    font-size: 20px;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25);
    flex-shrink: 0;
}

.brand-meta h1 {
    font-size: 16px;
    font-weight: 800;
    letter-spacing: -0.3px;
    color: var(--text-pure);
    line-height: 1.2;
}

.brand-badge {
    display: inline-block;
    font-size: 9px;
    font-weight: 700;
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: 6px;
    padding: 1px 6px;
    margin-top: 3px;
    letter-spacing: 0.5px;
}

.nav-section-label {
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-muted);
    padding: 0 10px 8px;
    display: block;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 11px 14px;
    border-radius: var(--radius-md);
    color: var(--text-dim);
    font-size: 13px;
    font-weight: 600;
    transition: var(--transition);
    position: relative;
    border: 1px solid transparent;
}

.nav-item:hover {
    background: #f1f5f9;
    color: var(--text-pure);
    transform: translateX(3px);
}

.nav-item.active {
    background: var(--primary-light);
    border-color: rgba(37, 99, 235, 0.25);
    color: var(--primary);
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.08);
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 18%;
    bottom: 18%;
    width: 3.5px;
    border-radius: 0 4px 4px 0;
    background: var(--primary);
    box-shadow: 0 0 8px rgba(37, 99, 235, 0.4);
}

.nav-icon {
    font-size: 17px;
    width: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.nav-tag {
    margin-left: auto;
    font-size: 9px;
    font-weight: 700;
    padding: 2px 7px;
    border-radius: 20px;
    letter-spacing: 0.5px;
}

.nav-tag.live {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.nav-tag.rfid {
    background: var(--accent-light);
    color: var(--accent);
    border: 1px solid rgba(124, 58, 237, 0.3);
}

.nav-tag.info {
    background: var(--info-light);
    color: var(--info);
    border: 1px solid rgba(2, 132, 199, 0.3);
}

.nav-tag.locked {
    background: #f1f5f9;
    color: #64748b;
    border: 1px solid #cbd5e1;
}

.nav-item.disabled {
    opacity: 0.45;
    cursor: not-allowed !important;
    filter: grayscale(0.5);
    background: transparent !important;
    border-color: transparent !important;
    transform: none !important;
}

.nav-item.disabled:hover {
    background: transparent !important;
    color: var(--text-dim) !important;
    transform: none !important;
}

/* ============================================================
   SIDEBAR ROOM STATUS CARD (CURRENT SELECTED ROOM)
   ============================================================ */
.sidebar-room-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 13px 14px;
    margin-top: auto;
    margin-bottom: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.sidebar-room-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 10px;
    font-weight: 700;
    color: var(--text-muted);
    letter-spacing: 0.8px;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.unselected-box {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.unselected-hint {
    font-size: 11px;
    color: var(--text-muted);
    line-height: 1.35;
    margin: 0;
}

.selected-box {
    display: flex;
    flex-direction: column;
    gap: 7px;
}

.btn-change-room {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 5px;
    width: 100%;
    padding: 6px 10px;
    border-radius: var(--radius-md);
    background: #eff6ff;
    border: 1px solid rgba(37, 99, 235, 0.25);
    color: var(--primary);
    font-size: 11px;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
}

.btn-change-room:hover {
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.2);
}

/* Sidebar System Status */
.system-card {
    background: #f8fafc;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 12px;
}

.system-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 4px;
}

.system-card-header span {
    font-size: 10px;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.system-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--warning);
    box-shadow: 0 0 6px var(--warning);
    transition: var(--transition);
}

.system-dot.online {
    background: var(--success);
    box-shadow: 0 0 6px var(--success);
    animation: pulseDot 2s infinite;
}

.system-card strong {
    display: block;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-pure);
}

.system-card small {
    display: block;
    font-size: 10px;
    color: var(--text-muted);
    margin-top: 2px;
}

/* ============================================================
   TOPBAR & APP HEADER
   ============================================================ */
.main {
    margin-left: var(--sidebar-width);
    width: calc(100% - var(--sidebar-width));
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.topbar {
    height: var(--topbar-height);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--card-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 28px;
    position: sticky;
    top: 0;
    z-index: 90;
    box-shadow: 0 1px 4px rgba(15, 23, 42, 0.03);
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.mobile-menu-btn {
    display: none;
    width: 38px;
    height: 38px;
    border-radius: var(--radius-md);
    background: #f1f5f9;
    border: 1px solid var(--card-border);
    color: var(--text-pure);
    font-size: 18px;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
}

.mobile-menu-btn:hover {
    background: #e2e8f0;
}

.breadcrumb-nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.breadcrumb-trail {
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 0.8px;
    color: var(--primary);
    text-transform: uppercase;
}

.topbar-title {
    font-size: 18px;
    font-weight: 800;
    color: var(--text-pure);
    letter-spacing: -0.3px;
}

.topbar-right {
    display: flex;
    align-items: center;
    gap: 14px;
}

.live-clock-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #f8fafc;
    border: 1px solid var(--card-border);
    border-radius: 30px;
    padding: 6px 14px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-dim);
}

.live-clock-badge span.clock-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--primary);
    box-shadow: 0 0 6px rgba(37, 99, 235, 0.5);
}

.server-status-pill {
    display: flex;
    align-items: center;
    gap: 10px;
    background: #f8fafc;
    border: 1px solid var(--card-border);
    border-radius: 30px;
    padding: 6px 14px;
}

.status-indicator-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--warning);
    box-shadow: 0 0 6px var(--warning);
    transition: var(--transition);
}

.status-indicator-dot.online {
    background: var(--success);
    box-shadow: 0 0 8px rgba(16, 185, 129, 0.6);
    animation: pulseDot 2s infinite;
}

.server-meta {
    display: flex;
    flex-direction: column;
}

.server-meta strong {
    font-size: 11px;
    font-weight: 700;
    color: var(--text-pure);
    line-height: 1.2;
}

.server-meta small {
    font-size: 9px;
    color: var(--text-muted);
}

/* ============================================================
   CONTENT VIEWS CONTAINER
   ============================================================ */
.content-wrapper {
    flex: 1;
    max-width: 1560px;
    width: 100%;
    margin: 0 auto;
    padding: 24px 28px 40px;
}

.content-view {
    animation: viewFadeIn 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes viewFadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================================
   MULTI-ROOM INTERACTIVE SWITCHER BAR (HEADER RIBBON)
   ============================================================ */
.multi-room-bar {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 12px 18px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    box-shadow: var(--card-glow);
}

.multi-room-bar-left {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.multi-room-bar-label {
    font-size: 11px;
    font-weight: 800;
    color: var(--text-muted);
    letter-spacing: 0.8px;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    gap: 6px;
    margin-right: 6px;
}

.room-tabs-container {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.room-tab-pill {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 8px 16px;
    border-radius: 30px;
    background: #f8fafc;
    border: 1.5px solid var(--card-border);
    color: var(--text-dim);
    font-size: 12px;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
}

.room-tab-pill:hover {
    background: #f1f5f9;
    border-color: var(--card-border-hover);
    color: var(--text-pure);
    transform: translateY(-1px);
}

.room-tab-pill.active {
    background: var(--primary-light);
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
}

.room-tab-pill .room-pill-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 6px var(--success);
}

.room-tab-pill .room-pill-id {
    font-size: 10px;
    font-weight: 800;
    padding: 1px 6px;
    border-radius: 4px;
    background: rgba(0, 0, 0, 0.05);
}

.room-tab-pill.active .room-pill-id {
    background: rgba(37, 99, 235, 0.15);
    color: var(--primary);
}

.room-tab-pill.offline {
    background: #f8fafc;
    border-color: #e2e8f0;
    color: #94a3b8;
    cursor: not-allowed;
    opacity: 0.65;
}

.room-tab-pill.offline:hover {
    background: #f8fafc;
    border-color: #e2e8f0;
    transform: none;
    color: #94a3b8;
}

.room-tab-pill.offline .room-pill-dot {
    background: #94a3b8;
    box-shadow: none;
}

.btn-back-rooms {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border-radius: 20px;
    background: #eff6ff;
    border: 1px solid rgba(37, 99, 235, 0.25);
    color: var(--primary);
    font-weight: 700;
    font-size: 11px;
    cursor: pointer;
    transition: var(--transition);
}

.btn-back-rooms:hover {
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

/* ============================================================
   ROOMS PORTAL GRID (ONLINE / OFFLINE ARCHITECTURE)
   ============================================================ */
.rooms-portal-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 20px;
}

.room-portal-card {
    background: #ffffff;
    border-radius: var(--radius-xl);
    border: 1.5px solid var(--card-border);
    padding: 22px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    box-shadow: var(--card-glow);
}

/* Online Room: Vibrant Green Aesthetic */
.room-portal-card.online {
    border-color: rgba(16, 185, 129, 0.45);
    cursor: pointer;
}

.room-portal-card.online:hover {
    transform: translateY(-4px);
    border-color: var(--success);
    box-shadow: 0 14px 30px -4px rgba(16, 185, 129, 0.18), 0 4px 10px -2px rgba(0, 0, 0, 0.04);
}

.room-portal-card.online::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #10b981 0%, #059669 100%);
}

/* Offline Room: Muted Gray, Disabled Aesthetic */
.room-portal-card.offline {
    background: #f8fafc;
    border: 1.5px dashed #cbd5e1;
    opacity: 0.7;
    cursor: not-allowed;
    filter: grayscale(0.85);
}

.room-portal-card.offline:hover {
    background: #f1f5f9;
}

.room-portal-card.offline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: #cbd5e1;
}

.portal-card-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}

.portal-card-title-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.portal-room-icon {
    width: 46px;
    height: 46px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
}

.room-portal-card.online .portal-room-icon {
    background: rgba(16, 185, 129, 0.12);
    border: 1px solid rgba(16, 185, 129, 0.25);
    color: var(--success);
}

.room-portal-card.offline .portal-room-icon {
    background: #e2e8f0;
    border: 1px solid #cbd5e1;
    color: #94a3b8;
}

.portal-room-name {
    font-size: 16px;
    font-weight: 800;
    color: var(--text-pure);
    margin-bottom: 3px;
}

.portal-room-id-tag {
    font-size: 11px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 6px;
    background: #f1f5f9;
    color: var(--text-muted);
}

.room-portal-card.online .portal-room-id-tag {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
}

.portal-status-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 800;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.portal-status-badge.online {
    background: #ecfdf5;
    color: #059669;
    border: 1px solid rgba(16, 185, 129, 0.35);
}

.portal-status-badge.online .pulse-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: #10b981;
    box-shadow: 0 0 6px #10b981;
    animation: pulseDot 2s infinite;
}

.portal-status-badge.offline {
    background: #e2e8f0;
    color: #64748b;
    border: 1px solid #cbd5e1;
}

.portal-status-badge.offline .offline-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: #94a3b8;
}

.portal-card-body {
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 14px 0;
    border-top: 1px solid var(--card-border);
    border-bottom: 1px solid var(--card-border);
    margin-bottom: 16px;
}

.portal-info-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
}

.portal-info-row span:first-child {
    color: var(--text-muted);
    font-weight: 600;
}

.portal-info-row strong {
    color: var(--text-main);
    font-weight: 700;
}

.btn-portal-access {
    width: 100%;
    padding: 11px 16px;
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn-portal-access.online {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
}

.btn-portal-access.online:hover {
    background: linear-gradient(135deg, #059669 0%, #047857 100%);
    box-shadow: 0 6px 16px rgba(16, 185, 129, 0.35);
    transform: translateY(-1px);
}

.btn-portal-access.offline {
    background: #e2e8f0;
    color: #94a3b8;
    border: 1px solid #cbd5e1;
    cursor: not-allowed;
}

/* Offline alert banner inside Dashboard */
.room-offline-banner {
    background: #fff1f2;
    border: 1.5px solid #fecdd3;
    border-radius: var(--radius-lg);
    padding: 14px 20px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    animation: viewFadeIn 0.28s ease;
}

.room-offline-banner-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.room-offline-banner-content .banner-icon {
    font-size: 24px;
}

.room-offline-banner-content strong {
    display: block;
    font-size: 13px;
    color: var(--danger);
    font-weight: 800;
}

.room-offline-banner-content span {
    font-size: 12px;
    color: #9f1239;
}

/* ============================================================
   ROOM HERO BANNER
   ============================================================ */
.room-hero-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 22px 26px;
    margin-bottom: 24px;
    position: relative;
    overflow: hidden;
    box-shadow: var(--card-glow);
}

.room-hero-card::before {
    content: '';
    position: absolute;
    right: -40px;
    top: -40px;
    width: 200px;
    height: 200px;
    background: radial-gradient(circle, rgba(37, 99, 235, 0.06) 0%, transparent 70%);
    pointer-events: none;
}

.room-hero-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    position: relative;
    z-index: 1;
}

.room-hero-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.room-hero-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.2);
    font-size: 26px;
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.1);
    flex-shrink: 0;
}

.room-hero-details h2 {
    font-size: 20px;
    font-weight: 800;
    color: var(--text-pure);
    letter-spacing: -0.4px;
    margin-bottom: 5px;
}

.room-meta-tags {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.meta-chip {
    font-size: 10px;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 6px;
    background: #f1f5f9;
    border: 1px solid var(--card-border);
    color: var(--text-dim);
}

.meta-chip.active-chip {
    background: var(--success-light);
    border-color: rgba(16, 185, 129, 0.3);
    color: var(--success);
}

.room-hero-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.custom-select {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 8px 12px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-main);
    outline: none;
    transition: var(--transition);
    cursor: pointer;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.custom-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

/* ============================================================
   KPI METRICS GRID (TELEMETRY SUMMARY)
   ============================================================ */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.kpi-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 18px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--card-glow);
    transition: var(--transition);
}

.kpi-card:hover {
    background: var(--card-bg-hover);
    border-color: var(--card-border-hover);
    transform: translateY(-2px);
    box-shadow: var(--card-glow-elevated);
}

.kpi-icon {
    width: 46px;
    height: 46px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}

.kpi-icon.temp { background: var(--danger-light); color: var(--danger); border: 1px solid rgba(239, 68, 68, 0.2); }
.kpi-icon.hum  { background: var(--info-light); color: var(--info); border: 1px solid rgba(2, 132, 199, 0.2); }
.kpi-icon.gas  { background: var(--warning-light); color: var(--warning); border: 1px solid rgba(245, 158, 11, 0.2); }
.kpi-icon.card { background: var(--accent-light); color: var(--accent); border: 1px solid rgba(124, 58, 237, 0.2); }

.kpi-body {
    display: flex;
    flex-direction: column;
}

.kpi-body span {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 2px;
}

.kpi-body strong {
    font-size: 20px;
    font-weight: 800;
    color: var(--text-pure);
    letter-spacing: -0.4px;
}

/* ============================================================
   SECTIONS & SECTION HEADERS
   ============================================================ */
.section {
    margin-bottom: 28px;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.section-title-wrap {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.section-eyebrow {
    font-size: 10px;
    font-weight: 800;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--primary);
}

.section-header h3 {
    font-size: 17px;
    font-weight: 800;
    color: var(--text-pure);
    letter-spacing: -0.3px;
}

.live-badge {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    background: var(--success-light);
    border: 1px solid rgba(16, 185, 129, 0.3);
    border-radius: 30px;
    padding: 5px 12px;
    font-size: 10px;
    font-weight: 800;
    color: var(--success);
    letter-spacing: 0.5px;
}

.live-badge span {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 6px var(--success);
    animation: pulseDot 1.8s infinite;
}

/* ============================================================
   ENVIRONMENTAL TELEMETRY SENSOR CARDS
   ============================================================ */
.sensor-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.sensor-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 20px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--card-glow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.sensor-card:hover {
    background: var(--card-bg-hover);
    border-color: var(--card-border-hover);
    transform: translateY(-3px);
    box-shadow: var(--card-glow-elevated);
}

.sensor-top {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 18px;
}

.sensor-label-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.sensor-icon-box {
    width: 42px;
    height: 42px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 19px;
    background: #f1f5f9;
    border: 1px solid var(--card-border);
}

.sensor-label-group h4 {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-pure);
}

.sensor-label-group span {
    font-size: 10px;
    color: var(--text-muted);
}

.sensor-status-tag {
    font-size: 9px;
    font-weight: 800;
    padding: 3px 8px;
    border-radius: 6px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.sensor-status-tag.normal {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.sensor-status-tag.warning {
    background: var(--warning-light);
    color: var(--warning);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.sensor-status-tag.danger {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.35);
    animation: flashAlert 1.5s infinite;
}

.sensor-metric {
    display: flex;
    align-items: baseline;
    gap: 6px;
    margin-bottom: 14px;
}

.sensor-metric strong {
    font-size: 38px;
    font-weight: 800;
    letter-spacing: -1.2px;
    color: var(--text-pure);
    line-height: 1;
}

.sensor-metric span {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-muted);
}

.telemetry-bar-wrap {
    height: 6px;
    background: #e2e8f0;
    border-radius: 20px;
    overflow: hidden;
    margin-bottom: 16px;
}

.telemetry-bar-fill {
    height: 100%;
    border-radius: 20px;
    transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.telemetry-bar-fill.hum {
    background: linear-gradient(90deg, #38bdf8 0%, #0284c7 100%);
}

.telemetry-bar-fill.gas {
    background: linear-gradient(90deg, #10b981 0%, #f59e0b 70%, #ef4444 100%);
}

.telemetry-bar-fill.light {
    background: linear-gradient(90deg, #f59e0b 0%, #fbbf24 100%);
}

.door-state-box {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 0 12px;
}

.door-avatar {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    background: var(--accent-light);
    border: 1px solid rgba(124, 58, 237, 0.2);
}

.door-avatar-text strong {
    display: block;
    font-size: 14px;
    font-weight: 700;
    color: var(--text-pure);
}

.door-avatar-text span {
    font-size: 10px;
    color: var(--text-muted);
}

.sensor-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: auto;
    padding-top: 10px;
    border-top: 1px solid #f1f5f9;
    font-size: 10px;
    color: var(--text-muted);
}

.sensor-footer strong {
    color: var(--text-dim);
    font-weight: 600;
}

/* ============================================================
   CONTROL CENTER (MODE SWITCHER & DEVICE CARDS)
   ============================================================ */
.control-mode-container {
    display: flex;
    align-items: center;
    gap: 10px;
}

.control-mode-pill {
    display: inline-flex;
    background: #f1f5f9;
    border: 1px solid var(--card-border);
    border-radius: 30px;
    padding: 3px;
    gap: 2px;
}

.mode-btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 6px 14px;
    border-radius: 24px;
    border: 1px solid transparent;
    font-size: 11px;
    font-weight: 700;
    color: var(--text-dim);
    transition: var(--transition);
    cursor: pointer;
}

.mode-btn .mode-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--text-muted);
    transition: var(--transition);
}

.mode-btn:hover {
    color: var(--text-pure);
    background: rgba(255, 255, 255, 0.6);
}

.mode-btn#btn-mode-manual.active {
    background: #ffffff;
    border-color: rgba(37, 99, 235, 0.3);
    color: var(--primary);
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.15);
}

.mode-btn#btn-mode-manual.active .mode-dot {
    background: var(--primary);
    box-shadow: 0 0 6px var(--primary);
}

.mode-btn#btn-mode-auto.active {
    background: #ffffff;
    border-color: rgba(16, 185, 129, 0.35);
    color: var(--success);
    box-shadow: 0 2px 8px rgba(16, 185, 129, 0.18);
}

.mode-btn#btn-mode-auto.active .mode-dot {
    background: var(--success);
    box-shadow: 0 0 6px var(--success);
    animation: pulseDot 1.8s infinite;
}

.auto-mode-info-banner {
    display: flex;
    align-items: center;
    gap: 14px;
    background: linear-gradient(90deg, #ecfdf5 0%, #eff6ff 100%);
    border: 1px solid rgba(16, 185, 129, 0.3);
    border-radius: var(--radius-lg);
    padding: 12px 18px;
    margin-bottom: 20px;
    animation: viewFadeIn 0.25s ease;
}

.auto-info-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
    font-size: 17px;
    flex-shrink: 0;
}

.auto-info-text strong {
    display: block;
    font-size: 12px;
    font-weight: 700;
    color: #065f46;
    margin-bottom: 2px;
}

.auto-info-text span {
    font-size: 11px;
    color: #047857;
    line-height: 1.4;
}

.auto-info-text em {
    color: #065f46;
    font-style: normal;
    font-weight: 600;
}

/* Device Grid & Cards */
.device-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.device-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 20px;
    box-shadow: var(--card-glow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.device-card:hover {
    background: var(--card-bg-hover);
    border-color: var(--card-border-hover);
    transform: translateY(-2px);
    box-shadow: var(--card-glow-elevated);
}

.device-card.device-on {
    border-color: rgba(16, 185, 129, 0.4);
    background: #fdfefe;
    box-shadow: 0 8px 24px -4px rgba(16, 185, 129, 0.12);
}

.device-card-header {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 18px;
}

.device-avatar {
    width: 46px;
    height: 46px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 21px;
    background: #f1f5f9;
    border: 1px solid var(--card-border);
    transition: var(--transition);
}

.device-card.device-on .device-avatar.light {
    background: #fef9c3;
    border-color: #fde047;
    box-shadow: 0 0 16px rgba(250, 204, 21, 0.35);
}

.device-card.device-on .device-avatar.fan {
    background: #e0f2fe;
    border-color: #7dd3fc;
    box-shadow: 0 0 16px rgba(56, 189, 248, 0.35);
}

.device-card.device-on .device-avatar.fan span {
    display: inline-block;
    animation: spin 1.2s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.device-card.device-on .device-avatar.ac {
    background: #ede9fe;
    border-color: #c4b5fd;
    box-shadow: 0 0 16px rgba(124, 58, 237, 0.3);
}

.device-title h4 {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-pure);
}

.device-title span {
    font-size: 10px;
    color: var(--text-muted);
}

.device-status-badge {
    margin-left: auto;
    font-size: 9px;
    font-weight: 800;
    padding: 4px 10px;
    border-radius: 6px;
    letter-spacing: 0.5px;
    background: #f1f5f9;
    color: var(--text-muted);
    border: 1px solid var(--card-border);
    transition: var(--transition);
}

.device-status-badge.on {
    background: var(--success-light);
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.4);
    box-shadow: 0 2px 6px rgba(16, 185, 129, 0.15);
}

.device-action-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 14px;
    border-top: 1px solid #f1f5f9;
}

.device-state-text span {
    display: block;
    font-size: 10px;
    color: var(--text-muted);
}

.device-state-text strong {
    font-size: 13px;
    font-weight: 700;
    color: var(--text-pure);
}

.device-button-group {
    display: flex;
    gap: 8px;
}

.btn-device {
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.4px;
    border: 1px solid var(--card-border);
    background: #ffffff;
    color: var(--text-dim);
    transition: var(--transition);
    cursor: pointer;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.btn-device:hover {
    transform: translateY(-1px);
    box-shadow: 0 3px 8px rgba(0, 0, 0, 0.08);
}

.btn-device.btn-turn-on:hover {
    background: var(--success);
    color: #ffffff;
    border-color: var(--success);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-device.btn-turn-off:hover {
    background: var(--danger);
    color: #ffffff;
    border-color: var(--danger);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

/* ============================================================
   BOTTOM GRID: CHART & ALERT PANELS
   ============================================================ */
.bottom-grid {
    display: grid;
    grid-template-columns: 1.8fr 1fr;
    gap: 16px;
    margin-bottom: 24px;
}

.panel-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 20px;
    box-shadow: var(--card-glow);
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
}

.chart-unit-pill {
    font-size: 10px;
    font-weight: 700;
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.2);
    padding: 3px 8px;
    border-radius: 6px;
}

.chart-container {
    height: 260px;
    position: relative;
    width: 100%;
}

.chart-empty-state {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 600;
    pointer-events: none;
}

.alert-counter-badge {
    min-width: 24px;
    height: 24px;
    border-radius: 12px;
    background: var(--success-light);
    color: var(--success);
    font-size: 11px;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 7px;
}

.alert-feed {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.alert-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: var(--radius-md);
    background: #f8fafc;
    border: 1px solid var(--card-border);
    transition: var(--transition);
}

.alert-item.normal {
    background: #f0fdf4;
    border-color: #bbf7d0;
}

.alert-item.danger {
    background: #fef2f2;
    border-color: #fecaca;
}

.alert-icon-box {
    width: 34px;
    height: 34px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    font-weight: 800;
    flex-shrink: 0;
}

.alert-icon-box.normal { background: var(--success-light); color: var(--success); }
.alert-icon-box.danger { background: var(--danger-light); color: var(--danger); }

.alert-item strong {
    display: block;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-pure);
}

.alert-item span {
    font-size: 10px;
    color: var(--text-muted);
}

/* ============================================================
   PHÂN HỆ ĐIỂM DANH (ATTENDANCE SUB-SYSTEM)
   ============================================================ */
.attendance-top-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-input-group {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 6px 12px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.filter-input-group label {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
}

.filter-input-group input[type="date"] {
    background: transparent;
    border: none;
    outline: none;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-pure);
    cursor: pointer;
}

/* Custom Standard Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-size: 12px;
    font-weight: 700;
    transition: var(--transition);
    border: 1px solid transparent;
    cursor: pointer;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background: var(--primary);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
    background: var(--primary-dark);
    box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
    transform: translateY(-1px);
}

.btn-secondary {
    background: #ffffff;
    border: 1px solid var(--card-border);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: #f1f5f9;
    border-color: var(--card-border-hover);
    color: var(--text-pure);
}

.btn-accent {
    background: var(--warning);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.25);
}

.btn-accent:hover {
    background: #d97706;
    box-shadow: 0 6px 16px rgba(245, 158, 11, 0.35);
    transform: translateY(-1px);
}

.btn-danger-outline {
    background: #ffffff;
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: var(--danger);
}

.btn-danger-outline:hover {
    background: var(--danger-light);
    border-color: var(--danger);
}

.btn-xs {
    padding: 4px 8px;
    font-size: 10px;
    border-radius: var(--radius-sm);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 11px;
}

.btn-warning {
    background: var(--warning-light);
    color: #b45309;
    border: 1px solid rgba(245, 158, 11, 0.35);
}

.btn-warning:hover {
    background: #fde68a;
}

/* Attendance KPI Grid */
.attendance-kpi-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.attendance-kpi-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 18px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: var(--card-glow);
    transition: var(--transition);
}

.attendance-kpi-card:hover {
    background: var(--card-bg-hover);
    transform: translateY(-2px);
    box-shadow: var(--card-glow-elevated);
}

.attendance-kpi-icon {
    width: 46px;
    height: 46px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 21px;
    flex-shrink: 0;
}

.attendance-kpi-icon.total   { background: var(--primary-light); color: var(--primary); border: 1px solid rgba(37, 99, 235, 0.2); }
.attendance-kpi-icon.present { background: var(--success-light); color: var(--success); border: 1px solid rgba(16, 185, 129, 0.2); }
.attendance-kpi-icon.late    { background: var(--warning-light); color: var(--warning); border: 1px solid rgba(245, 158, 11, 0.2); }
.attendance-kpi-icon.absent  { background: var(--danger-light); color: var(--danger); border: 1px solid rgba(239, 68, 68, 0.2); }

/* Table Container & Tables */
.table-container-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--card-glow);
    margin-bottom: 24px;
}

.table-header-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 22px;
    border-bottom: 1px solid var(--card-border);
    flex-wrap: wrap;
    gap: 12px;
    background: #fafafa;
}

.search-input-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 7px 12px;
    min-width: 260px;
    transition: var(--transition);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.search-input-wrap:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.search-input-wrap input {
    background: none;
    border: none;
    outline: none;
    font-size: 12px;
    color: var(--text-pure);
    width: 100%;
}

.table-responsive {
    overflow-x: auto;
    width: 100%;
}

.modern-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 12px;
    text-align: left;
}

.modern-table th {
    background: #f8fafc;
    color: var(--text-muted);
    font-size: 10px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    padding: 12px 18px;
    border-bottom: 1px solid var(--card-border);
    white-space: nowrap;
}

.modern-table td {
    padding: 13px 18px;
    border-bottom: 1px solid #f1f5f9;
    color: var(--text-main);
    vertical-align: middle;
}

.modern-table tbody tr {
    transition: var(--transition);
}

.modern-table tbody tr:hover {
    background: #f8fafc;
}

.table-empty-cell {
    text-align: center;
    padding: 36px !important;
    color: var(--text-muted);
    font-weight: 600;
}

/* Table Avatar & Chip Elements */
.student-avatar-cell {
    display: flex;
    align-items: center;
    gap: 12px;
}

.student-avatar-circle {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.3);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 11px;
    font-weight: 800;
    flex-shrink: 0;
}

.student-name-meta strong {
    display: block;
    font-size: 13px;
    font-weight: 700;
    color: var(--text-pure);
}

.student-name-meta small {
    font-size: 10px;
    color: var(--text-muted);
}

.card-uid-pill {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-family: 'JetBrains Mono', monospace, Consolas, sans-serif;
    font-size: 11px;
    font-weight: 700;
    color: var(--accent);
    background: var(--accent-light);
    border: 1px solid rgba(124, 58, 237, 0.25);
    padding: 2px 8px;
    border-radius: 6px;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 10px;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 20px;
    letter-spacing: 0.3px;
}

.status-badge.ontime {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.status-badge.late {
    background: var(--warning-light);
    color: #b45309;
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.status-badge.assigned {
    background: var(--primary-light);
    color: var(--primary);
    border: 1px solid rgba(37, 99, 235, 0.3);
}

.status-badge.unassigned {
    background: #f1f5f9;
    color: var(--text-muted);
    border: 1px solid var(--card-border);
}

.status-badge.excused {
    background: #f5f3ff;
    color: #7c3aed;
    border: 1px solid rgba(124, 58, 237, 0.3);
}

.status-badge.absent {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.status-badge.active {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.35);
}

.status-badge.closed {
    background: #f1f5f9;
    color: var(--text-dim);
    border: 1px solid var(--card-border);
}

.mini-pill {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    font-weight: 600;
    padding: 3px 8px;
    border-radius: 6px;
    border: 1px solid transparent;
}

.mini-pill.total {
    background: #f1f5f9;
    color: var(--text-pure);
    border-color: var(--card-border);
}

.mini-pill.present {
    background: var(--success-light);
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.25);
}

.mini-pill.late {
    background: var(--warning-light);
    color: #b45309;
    border-color: rgba(245, 158, 11, 0.25);
}

.mini-pill.excused {
    background: #f5f3ff;
    color: #7c3aed;
    border-color: rgba(124, 58, 237, 0.25);
}

.mini-pill.absent {
    background: var(--danger-light);
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.25);
}

.event-type-badge {
    font-size: 10px;
    font-weight: 800;
    padding: 3px 8px;
    border-radius: 6px;
    letter-spacing: 0.5px;
}

.event-type-badge.in {
    background: var(--primary-light);
    color: var(--primary);
}

.event-type-badge.out {
    background: var(--accent-light);
    color: var(--accent);
}

.action-btn-group {
    display: flex;
    align-items: center;
    gap: 6px;
}

/* ============================================================
   MODALS (CLEAN LIGHT ELEVATION)
   ============================================================ */
.modal-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.45);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
    z-index: 1000;
    animation: modalFadeIn 0.2s ease-out;
}

@keyframes modalFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-dialog {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 540px;
    padding: 24px 28px;
    box-shadow: 0 20px 40px -10px rgba(15, 23, 42, 0.2);
    animation: modalSlideUp 0.24s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalSlideUp {
    from { transform: translateY(16px) scale(0.98); opacity: 0; }
    to { transform: translateY(0) scale(1); opacity: 1; }
}

.modal-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--card-border);
}

.modal-title-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.modal-avatar-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.2);
    color: var(--primary);
}

.modal-title-group h3 {
    font-size: 16px;
    font-weight: 800;
    color: var(--text-pure);
}

.modal-title-group p {
    font-size: 11px;
    color: var(--text-muted);
}

.modal-close-btn {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f1f5f9;
    color: var(--text-muted);
    font-size: 16px;
    transition: var(--transition);
    cursor: pointer;
}

.modal-close-btn:hover {
    background: #e2e8f0;
    color: var(--text-pure);
}

.form-grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 12px;
}

.form-field {
    display: flex;
    flex-direction: column;
    gap: 5px;
    margin-bottom: 12px;
}

.form-field label {
    font-size: 11px;
    font-weight: 700;
    color: var(--text-dim);
}

.custom-input {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-md);
    padding: 9px 12px;
    font-size: 12px;
    color: var(--text-pure);
    outline: none;
    transition: var(--transition);
    width: 100%;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.custom-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.input-with-button {
    display: flex;
    gap: 8px;
}

.form-help-tip {
    font-size: 10px;
    color: var(--text-muted);
    line-height: 1.4;
    margin-top: 3px;
}

.modal-actions {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--card-border);
}

/* ============================================================
   TOAST NOTIFICATION COMPONENT
   ============================================================ */
.toast-popup {
    position: fixed;
    right: 24px;
    bottom: 24px;
    min-width: 290px;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 16px 36px -6px rgba(15, 23, 42, 0.16);
    transform: translateY(100px);
    opacity: 0;
    transition: var(--transition);
    z-index: 2000;
}

.toast-popup.active {
    transform: translateY(0);
    opacity: 1;
}

.toast-icon-circle {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 800;
    flex-shrink: 0;
}

.toast-text strong {
    display: block;
    font-size: 12px;
    font-weight: 700;
    color: var(--text-pure);
}

.toast-text span {
    font-size: 10px;
    color: var(--text-muted);
}

/* ============================================================
   FOOTER
   ============================================================ */
.app-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 4px 0;
    margin-top: auto;
    font-size: 10px;
    color: var(--text-muted);
    border-top: 1px solid var(--card-border);
}

/* ============================================================
   KEYFRAME ANIMATIONS
   ============================================================ */
@keyframes pulseDot {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.3); opacity: 0.6; }
}

@keyframes flashAlert {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* ============================================================
   ACTIVE SESSION BANNER & ATTENDANCE CARDS
   ============================================================ */
.active-session-banner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 14px 20px;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.06) 0%, rgba(124, 58, 237, 0.06) 100%);
    border: 1px solid rgba(37, 99, 235, 0.22);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 16px -2px rgba(37, 99, 235, 0.08);
    margin-bottom: 20px;
    transition: var(--transition);
}

.active-session-banner:hover {
    border-color: rgba(37, 99, 235, 0.38);
    box-shadow: 0 6px 20px -2px rgba(37, 99, 235, 0.12);
}

.session-banner-left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.session-live-pulse {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
    animation: pulseRing 1.8s infinite;
    flex-shrink: 0;
}

@keyframes pulseRing {
    0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
    70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
    100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.session-banner-info {
    display: flex;
    flex-direction: column;
    gap: 3px;
}

.session-banner-title {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.session-banner-title strong {
    font-size: 14px;
    font-weight: 800;
    color: var(--text-pure);
}

.session-badge-class {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(37, 99, 235, 0.25);
    padding: 1px 8px;
    border-radius: 6px;
    font-family: 'JetBrains Mono', monospace;
}

.session-banner-time {
    font-size: 12px;
    color: var(--text-dim);
}

.btn-goto-attendance {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: var(--radius-md);
    background: var(--primary);
    color: #ffffff;
    font-size: 12px;
    font-weight: 700;
    transition: var(--transition);
    white-space: nowrap;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

.btn-goto-attendance:hover {
    background: var(--primary-dark);
    transform: translateX(2px);
}

/* RFID / ATTENDANCE VIEW TOP CARD */
.session-top-card {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-xl);
    padding: 22px 24px;
    margin-bottom: 20px;
    box-shadow: var(--card-glow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
}

.session-card-main {
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
    min-width: 280px;
}

.session-status-tag-row {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.session-status-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    font-weight: 800;
    padding: 3px 10px;
    border-radius: 20px;
    background: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.3);
    letter-spacing: 0.5px;
}

.session-status-badge.inactive {
    background: #f1f5f9;
    color: var(--text-muted);
    border-color: var(--card-border);
}

.session-subject-title {
    font-size: 20px;
    font-weight: 800;
    color: var(--text-pure);
    letter-spacing: -0.3px;
}

.session-details-row {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    font-size: 12px;
    color: var(--text-dim);
}

.session-details-row .detail-item strong {
    color: var(--text-pure);
}

.session-stats-group {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.session-stat-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 10px 16px;
    border-radius: var(--radius-md);
    min-width: 86px;
    border: 1px solid transparent;
    transition: var(--transition);
}

.session-stat-box.total {
    background: #f8fafc;
    border-color: var(--card-border);
}
.session-stat-box.present {
    background: var(--success-light);
    border-color: rgba(16, 185, 129, 0.25);
}
.session-stat-box.late {
    background: var(--warning-light);
    border-color: rgba(245, 158, 11, 0.25);
}
.session-stat-box.absent {
    background: var(--danger-light);
    border-color: rgba(239, 68, 68, 0.25);
}

.session-stat-box .stat-num {
    font-size: 20px;
    font-weight: 800;
    line-height: 1.1;
}
.session-stat-box.total .stat-num { color: var(--text-pure); }
.session-stat-box.present .stat-num { color: var(--success); }
.session-stat-box.late .stat-num { color: #b45309; }
.session-stat-box.absent .stat-num { color: var(--danger); }

.session-stat-box .stat-lbl {
    font-size: 10px;
    font-weight: 700;
    color: var(--text-muted);
    margin-top: 2px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

/* SUB-TABS NAVIGATION */
.attendance-sub-tabs {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    border-bottom: 2px solid var(--card-border);
    padding-bottom: 2px;
}

.sub-tab-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    font-size: 13px;
    font-weight: 700;
    color: var(--text-dim);
    border-radius: var(--radius-md) var(--radius-md) 0 0;
    position: relative;
    transition: var(--transition);
    border-bottom: 2px solid transparent;
    margin-bottom: -4px;
    background: none;
    cursor: pointer;
}

.sub-tab-btn:hover {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.04);
}

.sub-tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
    background: rgba(37, 99, 235, 0.06);
}

.subtab-badge {
    display: inline-block;
    font-size: 10px;
    font-weight: 800;
    padding: 1px 7px;
    border-radius: 12px;
    background: rgba(37, 99, 235, 0.15);
    color: var(--primary);
}

/* ============================================================
   SCHEDULE (TIMETABLE) & WEEKLY GRID STYLES
   ============================================================ */
.schedule-week-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 12px;
    align-items: start;
}

@media (max-width: 1400px) {
    .schedule-week-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 992px) {
    .schedule-week-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .schedule-week-grid {
        grid-template-columns: 1fr;
    }
}

.schedule-day-column {
    background: #ffffff;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    display: flex;
    flex-direction: column;
    min-height: 440px;
    overflow: hidden;
    transition: var(--transition);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
}

.schedule-day-column:hover {
    border-color: var(--card-border-hover);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.schedule-day-column.is-today {
    background: #fdfefe;
    border-color: rgba(37, 99, 235, 0.35);
    box-shadow: 0 0 20px rgba(37, 99, 235, 0.08);
}

.schedule-day-header {
    padding: 10px 12px;
    background: #f8fafc;
    border-bottom: 1px solid var(--card-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.schedule-day-title {
    font-size: 12px;
    font-weight: 800;
    color: var(--text-pure);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.schedule-day-count {
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 20px;
    background: #e2e8f0;
    color: var(--text-dim);
    font-weight: 700;
}

.schedule-day-column.is-today .schedule-day-title {
    color: var(--primary);
}

.schedule-day-column.is-today .schedule-day-count {
    background: var(--primary-light);
    color: var(--primary);
    border: 1px solid rgba(37, 99, 235, 0.25);
}

.schedule-card-list {
    padding: 8px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex: 1;
}

.schedule-item-card {
    padding: 10px;
    border-radius: var(--radius-md);
    border: 1px solid var(--card-border);
    background: #ffffff;
    display: flex;
    flex-direction: column;
    gap: 5px;
    transition: var(--transition);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}

.schedule-item-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08);
    border-color: var(--card-border-hover);
}

.schedule-item-card.shift-morning {
    border-left: 3.5px solid var(--success);
    background: #fafdfb;
}

.schedule-item-card.shift-afternoon {
    border-left: 3.5px solid var(--info);
    background: #fbfdff;
}

.schedule-item-card.shift-evening {
    border-left: 3.5px solid var(--accent);
    background: #fdfaff;
}

.schedule-item-time {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 11px;
    font-weight: 700;
    color: var(--text-pure);
}

.schedule-item-subject {
    font-size: 12px;
    font-weight: 700;
    color: var(--text-pure);
    line-height: 1.35;
}

.schedule-item-class {
    font-size: 11px;
    color: var(--primary);
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
}

.schedule-item-meta {
    font-size: 10px;
    color: var(--text-dim);
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding-top: 4px;
    border-top: 1px solid #f1f5f9;
}

.schedule-empty-day {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 120px;
    font-size: 12px;
    color: var(--text-muted);
    font-style: italic;
    text-align: center;
    padding: 18px 10px;
}

/* ============================================================
   RESPONSIVE DESIGN (TABLETS & MOBILE)
   ============================================================ */
@media (max-width: 1200px) {
    .kpi-grid, .attendance-kpi-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .sensor-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .bottom-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 868px) {
    .sidebar {
        transform: translateX(-100%);
        box-shadow: none;
    }
    .sidebar.open {
        transform: translateX(0);
        box-shadow: 0 0 40px rgba(0, 0, 0, 0.25);
    }
    .main {
        margin-left: 0;
        width: 100%;
    }
    .mobile-menu-btn {
        display: flex;
    }
    .topbar {
        padding: 0 18px;
    }
    .content-wrapper {
        padding: 16px 14px 28px;
    }
    .device-grid {
        grid-template-columns: 1fr;
    }
    .sensor-grid {
        grid-template-columns: 1fr;
    }
    .kpi-grid, .attendance-kpi-grid {
        grid-template-columns: 1fr;
    }
    .room-hero-inner {
        flex-direction: column;
        align-items: flex-start;
    }
    .multi-room-bar {
        flex-direction: column;
        align-items: flex-start;
    }
    .sidebar-backdrop.active {
        display: block;
        opacity: 1;
    }
}

.sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(15, 23, 42, 0.4);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 95;
    opacity: 0;
    transition: opacity 0.25s ease;
}