/* 
 * TERAS360 E-LEARNING SYSTEM 
 * Design System: V3 Glassmorphism & Vibrant HSE
 */

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #f59e0b;
    --secondary-dark: #d97706;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --dark: #0f172a;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--gray-800);
    background-color: var(--gray-50);
}

/* NAVBAR */
.navbar {
    background: rgba(15, 23, 42, 0.9) !important;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-md);
}

.navbar-brand {
    font-weight: 800;
    letter-spacing: -0.5px;
}

/* HERO SECTION */
.hero {
    background: linear-gradient(135deg, var(--gray-900) 0%, var(--primary-dark) 100%);
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.05) 0%, transparent 70%);
    pointer-events: none;
}

/* CARDS & PANELS */
.card {
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-xl);
    transition: all 0.3s ease;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary);
}

.card-header {
    background: transparent;
    border-bottom: 1px solid var(--gray-100);
    padding: 1.5rem;
}

.card-footer {
    background: var(--gray-50);
    border-top: none;
    padding: 1.25rem;
}

/* GLASSMORPHISM */
.glass-panel {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    box-shadow: 0 8px 32px rgba(31, 38, 135, 0.07);
    border-radius: var(--radius-2xl);
}

/* BUTTONS */
.btn {
    border-radius: var(--radius-md);
    padding: 0.6rem 1.5rem;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-warning {
    background: var(--secondary);
    border: none;
    color: var(--dark);
}

.btn-warning:hover {
    background: var(--secondary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3);
}

/* LEARNING INTERFACE */
.video-container {
    border-radius: var(--radius-xl);
    overflow: hidden;
    background: #000;
    box-shadow: var(--shadow-xl);
}

.lesson-list .list-group-item {
    border: none;
    margin-bottom: 5px;
    border-radius: var(--radius-md) !important;
    transition: all 0.2s;
}

.lesson-list .list-group-item.active {
    background-color: var(--primary);
    border-color: var(--primary);
}

.lesson-list .list-group-item:hover:not(.active) {
    background-color: var(--gray-100);
}

.lesson-content {
    color: var(--gray-700);
}

/* PROGRESS BAR */
.progress {
    background-color: var(--gray-200);
    border-radius: 100px;
}

.progress-bar {
    background: linear-gradient(90deg, var(--secondary) 0%, var(--secondary-dark) 100%);
    border-radius: 100px;
}

/* BADGES */
.badge {
    padding: 0.5em 1em;
    border-radius: 100px;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.7rem;
}

/* FOOTER */
footer {
    border-top: 1px solid var(--gray-200);
}

@media (max-width: 768px) {
    .hero { padding: 60px 0; }
    .display-4 { font-size: 2.5rem; }
}