/* ==============================================
   EduCore — Theme Engine CSS
   Premium Glassmorphic Design System · Light Only
   ============================================== */

/* ── Theme Custom Properties ──
   ALL colours and key design tokens live here.
   The JS theme-engine overrides these at runtime
   for multi-tenant white-labelling.
   ────────────────────────────────────────────── */
:root {
    /* ── Brand Colours ── */
    --primary:             #243665;
    --primary-light:       #34508a;
    --primary-dark:        #1a2849;
    --primary-rgb:         36, 54, 101;

    --accent:              #C5A02B;
    --accent-light:        #d4b545;
    --accent-dark:         #a68820;
    --accent-rgb:          197, 160, 43;

    --secondary:           #7E121E;
    --secondary-light:     #a01828;
    --secondary-rgb:       126, 18, 30;

    /* ── Surfaces ── */
    --bg-main:             #FFFFFF;
    --bg-page:             #F0F2F5;
    --bg-card:             #FFFFFF;
    --bg-input:            #F5F7FA;
    --bg-input-focus:      #FFFFFF;
    --bg-elevated:         #FFFFFF;

    /* ── Sidebar ── */
    --bg-sidebar:          #1C2D4F;
    --bg-sidebar-hover:    #253a61;
    --bg-sidebar-active:   var(--primary);
    --text-sidebar:        #CBD5E1;
    --text-sidebar-active: #FFFFFF;

    /* ── Typography ── */
    --text-primary:        #1A1A2E;
    --text-secondary:      #6B7280;
    --text-muted:          #9CA3AF;
    --text-inverse:        #FFFFFF;

    /* ── Borders ── */
    --border:              #E5E7EB;
    --border-light:        #F3F4F6;
    --border-focus:        var(--primary);

    /* ── Semantic Colours ── */
    --success:             #10B981;
    --success-light:       #D1FAE5;
    --success-dark:        #059669;
    --warning:             #F59E0B;
    --warning-light:       #FEF3C7;
    --warning-dark:        #D97706;
    --danger:              #EF4444;
    --danger-light:        #FEE2E2;
    --danger-dark:         #DC2626;
    --info:                #3B82F6;
    --info-light:          #DBEAFE;
    --info-dark:           #2563EB;

    /* ── Premium Shadows — layered, soft, elevated ── */
    --shadow-xs:           0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-sm:           0 1px 3px rgba(0, 0, 0, 0.06),
                           0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md:           0 4px 6px -1px rgba(0, 0, 0, 0.07),
                           0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg:           0 10px 15px -3px rgba(0, 0, 0, 0.08),
                           0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-xl:           0 20px 25px -5px rgba(0, 0, 0, 0.08),
                           0 8px 10px -6px rgba(0, 0, 0, 0.04);
    --shadow-2xl:          0 25px 50px -12px rgba(0, 0, 0, 0.15);
    --shadow-primary:      0 4px 14px rgba(var(--primary-rgb), 0.25);
    --shadow-accent:       0 4px 14px rgba(var(--accent-rgb), 0.25);

    /* ── Glassmorphism tokens ── */
    --glass-bg:            rgba(255, 255, 255, 0.95);
    --glass-bg-strong:     rgba(255, 255, 255, 0.98);
    --glass-border:        rgba(255, 255, 255, 0.45);
    --glass-blur:          12px;
    --glass-blur-strong:   20px;

    /* ── Radii ── */
    --radius-xs:           0.25rem;
    --radius-sm:           0.375rem;
    --radius-md:           0.5rem;
    --radius-lg:           0.75rem;
    --radius-xl:           1rem;
    --radius-2xl:          1.25rem;
    --radius-3xl:          1.5rem;
    --radius-full:         9999px;

    /* ── Transitions ── */
    --ease-out:            cubic-bezier(0.16, 1, 0.3, 1);
    --ease-spring:         cubic-bezier(0.34, 1.56, 0.64, 1);
    --transition:          all 0.2s var(--ease-out);
    --transition-slow:     all 0.35s var(--ease-out);
    --transition-fast:     all 0.12s ease;

    /* ── Gradient Presets ── */
    --gradient-primary:    linear-gradient(135deg, var(--primary), var(--primary-light));
    --gradient-accent:     linear-gradient(135deg, var(--accent), var(--accent-light));
    --gradient-sidebar:    linear-gradient(180deg, var(--bg-sidebar) 0%, color-mix(in srgb, var(--bg-sidebar) 85%, black) 100%);
    --gradient-page:       linear-gradient(135deg, #F0F2F5 0%, #E8EDF3 100%);
    --gradient-shimmer:    linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.4) 50%, transparent 100%);

    /* ── Typography ── */
    --font-sans:           'Inter', 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono:           'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    --letter-tight:        -0.025em;
    --letter-normal:        0em;
    --letter-wide:          0.05em;
    --letter-wider:         0.08em;

    /* ── Z-Index scale ── */
    --z-base:              1;
    --z-dropdown:          10;
    --z-sticky:            20;
    --z-header:            30;
    --z-sidebar:           40;
    --z-modal:             50;
    --z-toast:             60;
    --z-tooltip:           70;
}


/* ── GLASSMORPHISM UTILITIES ──────────────────── */

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
}

.glass-strong {
    background: var(--glass-bg-strong);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border: 1px solid var(--glass-border);
}

.glass-card {
    background: var(--glass-bg-strong);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm),
                inset 0 1px 0 rgba(255, 255, 255, 0.5);
    transition: var(--transition-slow);
}

.glass-card:hover {
    box-shadow: var(--shadow-lg),
                inset 0 1px 0 rgba(255, 255, 255, 0.6);
    transform: translateY(-2px);
}

/* Gradient border effect (pseudo-element approach) */
.gradient-border {
    position: relative;
    border: none !important;
}

.gradient-border::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 1.5px;
    background: linear-gradient(135deg,
        rgba(var(--primary-rgb), 0.3),
        rgba(var(--accent-rgb), 0.15),
        rgba(var(--primary-rgb), 0.05));
    -webkit-mask:
        linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
}


/* ── PREMIUM COMPONENT OVERRIDES ─────────────── */

/* -- Sidebar upgrade -- */
.sidebar.premium {
    background: var(--gradient-sidebar);
    border-right: 1px solid rgba(255, 255, 255, 0.06);
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.08);
}

.sidebar.premium .logo-section {
    padding: 1.75rem 1.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.sidebar.premium .nav-item {
    border-radius: var(--radius-lg);
    padding: 0.7rem 1rem;
    margin-bottom: 3px;
    position: relative;
    overflow: hidden;
}

.sidebar.premium .nav-item::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg,
        rgba(255, 255, 255, 0.08),
        transparent);
    opacity: 0;
    transition: opacity 0.25s ease;
}

.sidebar.premium .nav-item:hover::before {
    opacity: 1;
}

.sidebar.premium .nav-item.active {
    background: var(--gradient-primary);
    box-shadow: 0 4px 12px rgba(var(--primary-rgb), 0.35);
}

.sidebar.premium .nav-item.active::before {
    opacity: 0;
}

/* -- Premium stat card -- */
.stat-card.premium {
    border: none;
    border-radius: var(--radius-2xl);
    background: var(--bg-card);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
    transition: var(--transition-slow);
}

.stat-card.premium::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.stat-card.premium:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.stat-card.premium:hover::before {
    opacity: 1;
}

/* Gradient stat icon variants */
.stat-icon-gradient {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: white;
    flex-shrink: 0;
}

.stat-icon-gradient.primary {
    background: var(--gradient-primary);
    box-shadow: 0 4px 10px rgba(var(--primary-rgb), 0.3);
}

.stat-icon-gradient.accent {
    background: var(--gradient-accent);
    box-shadow: 0 4px 10px rgba(var(--accent-rgb), 0.3);
}

.stat-icon-gradient.success {
    background: linear-gradient(135deg, var(--success), #34d399);
    box-shadow: 0 4px 10px rgba(16, 185, 129, 0.3);
}

.stat-icon-gradient.danger {
    background: linear-gradient(135deg, var(--secondary), var(--secondary-light));
    box-shadow: 0 4px 10px rgba(var(--secondary-rgb), 0.3);
}

.stat-icon-gradient.warning {
    background: linear-gradient(135deg, var(--warning), #FBBF24);
    box-shadow: 0 4px 10px rgba(245, 158, 11, 0.3);
}

.stat-icon-gradient.info {
    background: linear-gradient(135deg, var(--info), #60A5FA);
    box-shadow: 0 4px 10px rgba(59, 130, 246, 0.3);
}

/* -- Premium buttons -- */
.btn.premium-primary {
    background: var(--gradient-primary);
    color: var(--text-inverse);
    border: none;
    box-shadow: var(--shadow-primary);
    position: relative;
    overflow: hidden;
}

.btn.premium-primary::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg,
        rgba(255, 255, 255, 0.15),
        transparent);
    opacity: 0;
    transition: opacity 0.2s ease;
}

.btn.premium-primary:hover {
    box-shadow: 0 6px 20px rgba(var(--primary-rgb), 0.35);
    transform: translateY(-1px);
}

.btn.premium-primary:hover::after {
    opacity: 1;
}

.btn.premium-primary:active {
    transform: translateY(0);
    box-shadow: var(--shadow-primary);
}

.btn.premium-accent {
    background: var(--gradient-accent);
    color: var(--text-inverse);
    border: none;
    box-shadow: var(--shadow-accent);
    position: relative;
    overflow: hidden;
}

.btn.premium-accent:hover {
    box-shadow: 0 6px 20px rgba(var(--accent-rgb), 0.35);
    transform: translateY(-1px);
}

/* -- Premium card variant -- */
.card.premium {
    border: none;
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    position: relative;
}

.card.premium .card-header {
    background: linear-gradient(180deg,
        rgba(var(--primary-rgb), 0.02) 0%,
        transparent 100%);
    border-bottom: 1px solid var(--border-light);
}

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

/* -- Premium table -- */
.data-table.premium th {
    background: linear-gradient(180deg, #F8FAFC, #F1F5F9);
    font-size: 0.7rem;
    letter-spacing: var(--letter-wider);
    color: var(--text-secondary);
    border-bottom: 1.5px solid var(--border);
    padding: 0.875rem 1rem;
}

.data-table.premium td {
    padding: 1rem;
    transition: background 0.15s ease;
}

.data-table.premium tbody tr {
    transition: var(--transition-fast);
}

.data-table.premium tbody tr:hover td {
    background: rgba(var(--primary-rgb), 0.025);
}

/* -- Premium modal -- */
.modal-content.premium {
    border: none;
    border-radius: var(--radius-3xl);
    box-shadow: var(--shadow-2xl),
                0 0 0 1px rgba(0, 0, 0, 0.04);
    animation: modalSlideUp 0.35s var(--ease-out) forwards;
}

@keyframes modalSlideUp {
    from {
        opacity: 0;
        transform: translateY(24px) scale(0.97);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-content.premium .modal-header {
    padding: 1.75rem 2rem 1.25rem;
    border-bottom: 1px solid var(--border-light);
}

.modal-content.premium .modal-header h2,
.modal-content.premium .modal-header h3 {
    font-weight: 700;
    letter-spacing: var(--letter-tight);
}

.modal-content.premium .modal-body {
    padding: 1.5rem 2rem;
}

.modal-content.premium .modal-footer {
    padding: 1.25rem 2rem;
    border-top: 1px solid var(--border-light);
    background: linear-gradient(180deg, transparent, rgba(0, 0, 0, 0.01));
}

/* -- Premium page header -- */
.page-header.premium {
    background: var(--glass-bg-strong);
    backdrop-filter: blur(var(--glass-blur-strong));
    -webkit-backdrop-filter: blur(var(--glass-blur-strong));
    border-bottom: 1px solid var(--glass-border);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

.page-header.premium h1 {
    font-weight: 800;
    letter-spacing: var(--letter-tight);
}

/* -- Premium form inputs -- */
.form-input.premium,
.premium .form-input {
    border-radius: var(--radius-lg);
    border: 1.5px solid var(--border);
    padding: 0.75rem 1rem;
    background: var(--bg-input);
    transition: var(--transition);
}

.form-input.premium:focus,
.premium .form-input:focus {
    border-color: var(--primary);
    background: var(--bg-input-focus);
    box-shadow: 0 0 0 3px rgba(var(--primary-rgb), 0.08),
                var(--shadow-sm);
}

/* -- Premium badge -- */
.badge.premium {
    font-weight: 700;
    letter-spacing: 0.02em;
    padding: 0.3rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.7rem;
    text-transform: uppercase;
}

/* -- Premium tooltip -- */
.tooltip-premium {
    position: relative;
}

.tooltip-premium::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: var(--text-primary);
    color: var(--text-inverse);
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.4rem 0.75rem;
    border-radius: var(--radius-md);
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: all 0.2s var(--ease-out);
    z-index: var(--z-tooltip);
}

.tooltip-premium:hover::after {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}


/* ── UTILITY CLASSES ─────────────────────────── */

/* Gradients */
.bg-gradient-primary   { background: var(--gradient-primary) !important; }
.bg-gradient-accent    { background: var(--gradient-accent) !important; }

/* Text gradients */
.text-gradient-primary {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.text-gradient-accent {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Elevation */
.elevation-1 { box-shadow: var(--shadow-xs); }
.elevation-2 { box-shadow: var(--shadow-sm); }
.elevation-3 { box-shadow: var(--shadow-md); }
.elevation-4 { box-shadow: var(--shadow-lg); }
.elevation-5 { box-shadow: var(--shadow-xl); }

/* Interactive hover lift */
.hover-lift {
    transition: var(--transition-slow);
}
.hover-lift:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.hover-glow {
    transition: var(--transition-slow);
}
.hover-glow:hover {
    box-shadow: 0 0 20px rgba(var(--primary-rgb), 0.15);
}

/* Dividers */
.divider-gradient {
    height: 1px;
    background: linear-gradient(90deg,
        transparent,
        var(--border),
        transparent);
    border: none;
}

/* Premium scrollbar for any element */
.premium-scrollbar::-webkit-scrollbar {
    width: 5px;
    height: 5px;
}

.premium-scrollbar::-webkit-scrollbar-track {
    background: transparent;
}

.premium-scrollbar::-webkit-scrollbar-thumb {
    background: rgba(var(--primary-rgb), 0.15);
    border-radius: var(--radius-full);
}

.premium-scrollbar::-webkit-scrollbar-thumb:hover {
    background: rgba(var(--primary-rgb), 0.3);
}

/* Focus ring utility */
.focus-ring:focus-visible {
    outline: none;
    box-shadow: 0 0 0 2px var(--bg-card),
                0 0 0 4px var(--primary);
}

/* Truncate text */
.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Smooth page background */
.page-bg-gradient {
    background: var(--gradient-page);
    min-height: 100vh;
}