:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #475569;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --dark-color: #0f172a;
    --light-bg: #f8fafc;
    --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.08);
}

body {
    font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--light-bg);
    color: #1e293b;
    min-height: 100vh;
}

/* WhatsApp Floating Button */
.whatsapp-float-btn {
    position: fixed;
    bottom: 25px;
    right: 25px;
    background-color: #25d366;
    color: #fff;
    border-radius: 50px;
    padding: 12px 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 20px rgba(37, 211, 102, 0.4);
    z-index: 1050;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.whatsapp-float-btn:hover {
    color: #fff;
    background-color: #1ebe5d;
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 6px 25px rgba(37, 211, 102, 0.5);
}

.whatsapp-float-btn i {
    font-size: 1.5rem;
}

/* Cards & Components */
.card-custom {
    border: none;
    border-radius: 14px;
    box-shadow: var(--card-shadow);
    transition: all 0.25s ease;
    background: #ffffff;
}

.card-custom:hover {
    box-shadow: var(--card-shadow-hover);
}

.stat-icon {
    width: 52px;
    height: 52px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

/* Sidebar Styling */
.app-sidebar {
    min-width: 250px;
    max-width: 250px;
    background: #0f172a;
    color: #94a3b8;
    min-height: 100vh;
    transition: all 0.3s;
}

.app-sidebar .nav-link {
    color: #94a3b8;
    padding: 10px 16px;
    border-radius: 8px;
    margin-bottom: 4px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all 0.2s;
}

.app-sidebar .nav-link:hover,
.app-sidebar .nav-link.active {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.1);
}

.app-sidebar .nav-link.active {
    background: #2563eb;
    color: #fff;
}

/* Mobile-Friendly Attendance Interface */
.attendance-card {
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    padding: 12px;
    margin-bottom: 10px;
    background: #ffffff;
    transition: background-color 0.2s;
}

.attendance-card.status-present {
    border-left: 5px solid #10b981;
    background-color: #f0fdf4;
}

.attendance-card.status-absent {
    border-left: 5px solid #ef4444;
    background-color: #fef2f2;
}

.attendance-card.status-late {
    border-left: 5px solid #f59e0b;
    background-color: #fffbeb;
}

/* Large Touch Buttons for Mobile Attendance */
.btn-attendance-toggle {
    min-width: 80px;
    padding: 8px 14px;
    font-weight: 600;
    border-radius: 8px;
    touch-action: manipulation;
}

/* Drag and Drop Zone */
.drag-source-col,
.drag-target-col {
    background: #f1f5f9;
    border-radius: 12px;
    padding: 16px;
    min-height: 480px;
}

.draggable-class-card {
    background: #ffffff;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    padding: 12px 16px;
    margin-bottom: 10px;
    cursor: grab;
    user-select: none;
    box-shadow: 0 1px 3px rgba(0,0,0,0.06);
    transition: all 0.2s ease;
}

.draggable-class-card:active {
    cursor: grabbing;
}

.draggable-class-card.dragging {
    opacity: 0.5;
    transform: scale(0.98);
}

.teacher-drop-target {
    background: #ffffff;
    border: 2px dashed #94a3b8;
    border-radius: 12px;
    padding: 14px;
    margin-bottom: 14px;
    transition: all 0.25s ease;
}

.teacher-drop-target.drag-over {
    border-color: #2563eb;
    background-color: #eff6ff;
    transform: scale(1.01);
}

/* Image Thumbnails */
.user-avatar-sm {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    object-fit: cover;
}

.user-avatar-md {
    width: 68px;
    height: 68px;
    border-radius: 50%;
    object-fit: cover;
}

.user-avatar-lg {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid #e2e8f0;
}

/* Autocomplete Dropdown for Parents */
.autocomplete-suggestions {
    border: 1px solid #cbd5e1;
    border-radius: 0 0 10px 10px;
    max-height: 220px;
    overflow-y: auto;
    position: absolute;
    width: 100%;
    background: #ffffff;
    z-index: 1000;
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
}

.autocomplete-item {
    padding: 10px 15px;
    cursor: pointer;
    border-bottom: 1px solid #f1f5f9;
}

.autocomplete-item:hover,
.autocomplete-item.selected {
    background-color: #eff6ff;
    color: #1d4ed8;
}

/* Status Badges */
.badge-active {
    background-color: #dcfce7;
    color: #15803d;
}

.badge-expired {
    background-color: #fee2e2;
    color: #b91c1c;
}

.badge-warning-custom {
    background-color: #fef3c7;
    color: #b45309;
}

/* Mobile responsive bottom navigation */
@media (max-width: 768px) {
    .app-sidebar {
        display: none;
    }
    .mobile-bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        height: 60px;
        background: #ffffff;
        box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.05);
        z-index: 1040;
        justify-content: space-around;
        align-items: center;
    }
    .mobile-bottom-nav a {
        color: #64748b;
        text-decoration: none;
        font-size: 0.75rem;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 3px;
    }
    .mobile-bottom-nav a.active {
        color: #2563eb;
        font-weight: 600;
    }
    .mobile-bottom-nav a i {
        font-size: 1.25rem;
    }
    body {
        padding-bottom: 75px;
    }
}

/* ==========================================================================
   LUMINOUS BACKLIGHT & MODERN NEO-GLASSMORPHISM STYLES
   ========================================================================== */

/* Luminous Hero Section */
.luminous-hero {
    position: relative;
    background-color: #0b1120;
    background-image: 
        radial-gradient(at 15% 25%, rgba(6, 182, 212, 0.38) 0px, transparent 55%),
        radial-gradient(at 85% 20%, rgba(139, 92, 246, 0.40) 0px, transparent 60%),
        radial-gradient(at 50% 85%, rgba(16, 185, 129, 0.28) 0px, transparent 55%),
        radial-gradient(at 80% 85%, rgba(59, 130, 246, 0.30) 0px, transparent 50%),
        linear-gradient(180deg, rgba(11, 17, 32, 0.65) 0%, rgba(15, 23, 42, 0.85) 100%),
        url('../img/hero-campus.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: scroll;
    overflow: hidden;
    padding-top: 4.5rem;
    padding-bottom: 5.5rem;
}

/* Luminous Ambient Glow Orbs */
.luminous-glow-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(90px);
    pointer-events: none;
    z-index: 1;
    opacity: 0.65;
    animation: floatOrb 8s ease-in-out infinite alternate;
}

.luminous-glow-orb-1 {
    width: 380px;
    height: 380px;
    background: radial-gradient(circle, #06b6d4 0%, rgba(6, 182, 212, 0) 70%);
    top: -100px;
    left: -80px;
}

.luminous-glow-orb-2 {
    width: 440px;
    height: 440px;
    background: radial-gradient(circle, #8b5cf6 0%, rgba(139, 92, 246, 0) 70%);
    top: 50px;
    right: -100px;
    animation-duration: 11s;
}

.luminous-glow-orb-3 {
    width: 340px;
    height: 340px;
    background: radial-gradient(circle, #10b981 0%, rgba(16, 185, 129, 0) 70%);
    bottom: -60px;
    left: 35%;
    animation-duration: 9s;
}

@keyframes floatOrb {
    0% { transform: translateY(0) scale(1); }
    100% { transform: translateY(-30px) scale(1.08); }
}

/* Modern Luminous Headline */
.text-gradient-luminous {
    background: linear-gradient(135deg, #ffffff 15%, #67e8f9 55%, #c084fc 85%, #60a5fa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 35px rgba(56, 189, 248, 0.35);
}

/* Luminous Pill Badges */
.badge-luminous {
    background: rgba(15, 23, 42, 0.7);
    color: #38bdf8;
    border: 1px solid rgba(56, 189, 248, 0.45);
    box-shadow: 0 0 20px rgba(56, 189, 248, 0.3);
    backdrop-filter: blur(12px);
}

/* Neo-Glassmorphism Portal Card */
.glass-card-luminous {
    background: rgba(15, 23, 42, 0.82);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 24px;
    box-shadow: 
        0 25px 50px -12px rgba(0, 0, 0, 0.7),
        0 0 45px rgba(56, 189, 248, 0.2),
        inset 0 1px 1px rgba(255, 255, 255, 0.25);
    position: relative;
    z-index: 2;
}

/* Luminous Portal Link Items with Rim Glow */
.portal-item-luminous {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 18px;
    background: rgba(30, 41, 59, 0.65);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    color: #ffffff;
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.portal-item-luminous:hover {
    transform: translateY(-3px) scale(1.01);
    color: #ffffff;
}

/* Color Aura variants */
.portal-cyan:hover {
    border-color: rgba(6, 182, 212, 0.75);
    box-shadow: 0 0 30px rgba(6, 182, 212, 0.4);
    background: rgba(14, 116, 144, 0.35);
}

.portal-emerald:hover {
    border-color: rgba(16, 185, 129, 0.75);
    box-shadow: 0 0 30px rgba(16, 185, 129, 0.4);
    background: rgba(4, 120, 87, 0.35);
}

.portal-amber:hover {
    border-color: rgba(245, 158, 11, 0.75);
    box-shadow: 0 0 30px rgba(245, 158, 11, 0.4);
    background: rgba(180, 83, 9, 0.35);
}

.portal-purple:hover {
    border-color: rgba(168, 85, 247, 0.75);
    box-shadow: 0 0 30px rgba(168, 85, 247, 0.4);
    background: rgba(126, 34, 206, 0.35);
}

/* Luminous Glow Button */
.btn-luminous-glow {
    background: linear-gradient(135deg, #2563eb, #06b6d4);
    color: #ffffff;
    border: none;
    box-shadow: 0 0 25px rgba(6, 182, 212, 0.5);
    transition: all 0.3s ease;
}

.btn-luminous-glow:hover {
    color: #ffffff;
    box-shadow: 0 0 35px rgba(6, 182, 212, 0.8);
    transform: translateY(-2px);
}

/* Luminous WhatsApp Button */
.btn-whatsapp-luminous {
    background: linear-gradient(135deg, #10b981, #059669);
    border: 1px solid rgba(52, 211, 153, 0.5);
    box-shadow: 0 0 30px rgba(16, 185, 129, 0.5);
    color: #ffffff;
}

.btn-whatsapp-luminous:hover {
    color: #ffffff;
    box-shadow: 0 0 45px rgba(16, 185, 129, 0.8);
    transform: translateY(-2px);
}

/* Luminous Feature Cards */
.feature-card-luminous {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 20px;
    padding: 24px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.feature-card-luminous:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 35px -10px rgba(37, 99, 235, 0.15), 0 0 20px rgba(6, 182, 212, 0.1);
    border-color: rgba(56, 189, 248, 0.5);
}