/* ============================================
   FILIPIKA - Aurora Learning Design System
   Accessible-first e-learning platform
   ============================================ */

/* === CSS VARIABLES === */
:root {
    /* Typography */
    --font-display: 'IBM Plex Sans', sans-serif;
    --font-body: 'Source Sans 3', sans-serif;
    --font-ui: 'Nunito Sans', sans-serif;

    /* Color Palette - WCAG AA Compliant */
    --color-primary: #0A5A5A;           /* Deep Teal */
    --color-primary-light: #0F7A7A;     /* Lighter Teal */
    --color-primary-dark: #064040;      /* Darker Teal */
    --color-secondary: #E8594F;         /* Burnt Coral */
    --color-secondary-light: #FF7A6E;   /* Light Coral */
    --color-accent: #F4A259;            /* Golden Amber */
    --color-accent-dark: #E08F42;       /* Dark Amber */

    /* Neutrals */
    --color-dark: #1E1E1E;              /* Deep Charcoal */
    --color-gray-900: #2D2D2D;
    --color-gray-800: #3D3D3D;
    --color-gray-700: #4D4D4D;
    --color-gray-600: #64748B;          /* Slate */
    --color-gray-500: #94A3B8;
    --color-gray-400: #CBD5E1;
    --color-gray-300: #E2E8F0;
    --color-gray-200: #F1F5F9;
    --color-gray-100: #F8FAFC;
    --color-light: #FFF8F0;             /* Warm Ivory */
    --color-white: #FFFFFF;

    /* Semantic Colors */
    --color-success: #0D7C4D;
    --color-danger: #DC2626;
    --color-warning: #D97706;
    --color-info: #0369A1;

    /* Backgrounds */
    --bg-body: var(--color-light);
    --bg-elevated: var(--color-white);
    --bg-subtle: var(--color-gray-100);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    --gradient-warm: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-accent) 100%);
    --gradient-hero: linear-gradient(120deg, #0A5A5A 0%, #0F7A7A 50%, #0A6B6B 100%);
    --gradient-aurora: linear-gradient(135deg, #0A5A5A 0%, #0F7A7A 25%, #E8594F 75%, #F4A259 100%);
    --gradient-subtle: linear-gradient(180deg, var(--color-light) 0%, var(--color-white) 100%);

    /* Shadows */
    --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-glow: 0 0 20px rgba(10, 90, 90, 0.3);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Focus */
    --focus-ring-width: 3px;
    --focus-ring-offset: 2px;
    --focus-ring-color: var(--color-primary);
}

/* === BASE STYLES === */
* {
    box-sizing: border-box;
}

body {
    font-family: var(--font-body);
    font-size: 1rem;
    line-height: 1.65;
    color: var(--color-dark);
    background-color: var(--bg-body);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--space-md);
    color: var(--color-dark);
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2rem);
}

h4 {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}

h5 {
    font-size: 1.25rem;
}

h6 {
    font-size: 1rem;
    font-weight: 600;
}

p {
    margin-bottom: var(--space-md);
}

.lead {
    font-size: 1.25rem;
    font-weight: 300;
    line-height: 1.6;
}

/* === LINKS === */
a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-base);
}

a:hover {
    color: var(--color-primary-light);
}

a:focus {
    outline: var(--focus-ring-width) solid var(--focus-ring-color);
    outline-offset: var(--focus-ring-offset);
    border-radius: var(--radius-sm);
}

/* === BUTTONS === */
.btn {
    font-family: var(--font-ui);
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-lg);
    border: 2px solid transparent;
    transition: all var(--transition-base);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    text-decoration: none;
    box-shadow: var(--shadow-sm);
}

.btn:focus {
    outline: var(--focus-ring-width) solid var(--focus-ring-color);
    outline-offset: var(--focus-ring-offset);
    box-shadow: var(--shadow-md);
}

.btn-primary {
    background: var(--gradient-primary);
    border-color: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-secondary-light) 100%);
    border-color: var(--color-secondary);
    color: white;
}

.btn-secondary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

.btn-light {
    background: white;
    border-color: var(--color-gray-300);
    color: var(--color-primary);
}

.btn-light:hover {
    background: var(--color-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline-primary {
    background: transparent;
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn-outline-primary:hover {
    background: var(--color-primary);
    color: white;
}

.btn-outline-light {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.5);
    color: white;
}

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

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* === CARDS === */
.card {
    background: var(--bg-elevated);
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    overflow: hidden;
}

.card:hover {
    box-shadow: var(--shadow-xl);
    transform: translateY(-4px);
}

.card-body {
    padding: var(--space-xl);
}

.card-header {
    background: var(--gradient-subtle);
    border-bottom: 1px solid var(--color-gray-300);
    padding: var(--space-lg) var(--space-xl);
    font-family: var(--font-ui);
    font-weight: 600;
}

.card-title {
    font-family: var(--font-display);
    font-weight: 600;
    color: var(--color-dark);
    margin-bottom: var(--space-sm);
}

/* === COURSE CARDS === */
.course-card {
    height: 100%;
    display: flex;
    flex-direction: column;
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
}

.course-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-aurora);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.course-card:hover::before {
    opacity: 1;
}

.course-card .card-body {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.course-card .course-meta {
    margin-top: auto;
    padding-top: var(--space-lg);
    border-top: 2px solid var(--color-gray-200);
    font-family: var(--font-ui);
}

.course-thumbnail {
    height: 220px;
    object-fit: cover;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* === NAVIGATION === */
.navbar {
    background: var(--gradient-hero) !important;
    box-shadow: var(--shadow-lg);
    padding: var(--space-md) 0;
    backdrop-filter: blur(10px);
}

.navbar-brand {
    font-family: var(--font-display);
    font-size: 1.75rem;
    font-weight: 800;
    color: white !important;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    transition: transform var(--transition-base);
}

.navbar-brand:hover {
    transform: scale(1.05);
}

.navbar-logo {
    height: 50px;
    width: auto;
    max-width: 200px;
    object-fit: contain;
    transition: transform var(--transition-base);
}

.navbar-logo:hover {
    transform: scale(1.05);
}

.nav-link {
    font-family: var(--font-ui);
    font-weight: 500;
    padding: var(--space-sm) var(--space-lg) !important;
    transition: all var(--transition-base);
    color: rgba(255, 255, 255, 0.9) !important;
    border-radius: var(--radius-md);
}

.nav-link:hover {
    background: rgba(255, 255, 255, 0.15);
    color: white !important;
}

.nav-link:focus {
    outline: var(--focus-ring-width) solid white;
    outline-offset: var(--focus-ring-offset);
}

/* === FOOTER === */
footer {
    background: linear-gradient(135deg, var(--color-dark) 0%, var(--color-gray-900) 100%);
    color: var(--color-gray-400);
    padding: var(--space-3xl) 0 var(--space-xl);
    margin-top: var(--space-3xl);
}

footer h3, footer h4 {
    color: white;
    font-family: var(--font-ui);
}

footer a {
    color: var(--color-gray-400);
    transition: color var(--transition-base);
}

footer a:hover {
    color: var(--color-accent);
}

.footer-logo {
    height: 50px;
    width: auto;
    max-width: 180px;
    object-fit: contain;
    display: block;
}

/* === FORMS === */
.form-label {
    font-family: var(--font-ui);
    font-weight: 600;
    color: var(--color-dark);
    margin-bottom: var(--space-sm);
}

.form-control,
.form-select {
    border: 2px solid var(--color-gray-300);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-body);
    transition: all var(--transition-base);
    background: white;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(10, 90, 90, 0.1);
    outline: none;
}

.form-control::placeholder {
    color: var(--color-gray-500);
}

/* === BADGES === */
.badge {
    font-family: var(--font-ui);
    font-weight: 600;
    padding: 0.375rem 0.875rem;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
}

.badge.bg-success {
    background: var(--color-success) !important;
}

.badge.bg-info {
    background: var(--color-info) !important;
}

.badge.bg-danger {
    background: var(--color-danger) !important;
}

/* === ALERTS === */
.alert {
    border-radius: var(--radius-lg);
    border-width: 2px;
    font-weight: 500;
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
}

.alert-success {
    background-color: #D1FAE5;
    border-color: var(--color-success);
    color: #065F46;
}

.alert-danger {
    background-color: #FEE2E2;
    border-color: var(--color-danger);
    color: #991B1B;
}

.alert-warning {
    background-color: #FEF3C7;
    border-color: var(--color-warning);
    color: #92400E;
}

.alert-info {
    background-color: #DBEAFE;
    border-color: var(--color-info);
    color: #1E3A8A;
}

/* === PROGRESS BARS === */
.progress {
    height: 1.5rem;
    border-radius: var(--radius-full);
    background-color: var(--color-gray-200);
    border: 1px solid var(--color-gray-300);
    overflow: hidden;
}

.progress-bar {
    background: var(--gradient-primary);
    font-family: var(--font-ui);
    font-weight: 700;
    line-height: 1.5rem;
    transition: width var(--transition-slow);
}

/* === BREADCRUMBS === */
.breadcrumb {
    background-color: transparent;
    padding: var(--space-lg) 0;
    margin-bottom: var(--space-md);
    font-family: var(--font-ui);
}

.breadcrumb-item a {
    color: var(--color-primary);
    text-decoration: none;
}

.breadcrumb-item a:hover {
    color: var(--color-primary-light);
    text-decoration: underline;
}

.breadcrumb-item.active {
    color: var(--color-gray-600);
}

/* === AUDIO PLAYER === */
.audio-player {
    background: var(--gradient-subtle);
    border: 2px solid var(--color-gray-300);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
}

.audio-controls button {
    min-width: 48px;
    min-height: 48px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-primary);
    background: white;
    color: var(--color-primary);
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

.audio-controls button:hover,
.audio-controls button:focus {
    background: var(--gradient-primary);
    color: white;
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.play-pause-btn {
    width: 64px !important;
    height: 64px !important;
}

.audio-progress {
    cursor: pointer;
}

.speed-selector {
    font-family: var(--font-ui);
    font-weight: 600;
}

/* === SKIP LINK === */
.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: var(--space-md) var(--space-xl);
    z-index: 9999;
    text-decoration: none;
    font-weight: 700;
    font-family: var(--font-ui);
    border-radius: 0 0 var(--radius-lg) 0;
    box-shadow: var(--shadow-lg);
}

.skip-link:focus {
    top: 0;
    color: white;
}

/* === ANIMATIONS === */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

@keyframes slideIn {
    from {
        transform: translateX(-20px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

/* Animate on scroll */
.animate-on-load {
    animation: fadeInUp var(--transition-slow) ease-out;
}

.animate-delay-1 {
    animation-delay: 100ms;
}

.animate-delay-2 {
    animation-delay: 200ms;
}

.animate-delay-3 {
    animation-delay: 300ms;
}

.animate-delay-4 {
    animation-delay: 400ms;
}

/* === HERO SECTION === */
.hero-section {
    background: var(--gradient-hero);
    color: white;
    padding: var(--space-3xl) 0;
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.4;
}

.hero-content {
    position: relative;
    z-index: 1;
}

/* === FEATURE CARDS === */
.feature-card {
    border: none;
    background: white;
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    height: 100%;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-md);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-2xl);
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
    color: white;
    font-size: 2rem;
}

/* === DROPDOWN === */
.dropdown-menu {
    border: 1px solid var(--color-gray-300);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    padding: var(--space-sm);
}

.dropdown-item {
    border-radius: var(--radius-md);
    padding: var(--space-sm) var(--space-lg);
    transition: all var(--transition-fast);
    font-family: var(--font-ui);
}

.dropdown-item:hover {
    background: var(--color-gray-100);
    color: var(--color-primary);
}

/* === LESSON NAVIGATION === */
.lesson-nav {
    border-top: 2px solid var(--color-gray-300);
    padding-top: var(--space-xl);
    margin-top: var(--space-2xl);
}

/* === LIST GROUPS === */
.list-group-item {
    border: 1px solid var(--color-gray-300);
    padding: var(--space-lg);
    transition: all var(--transition-base);
    font-family: var(--font-ui);
}

.list-group-item:hover {
    background: var(--color-gray-100);
}

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

/* === TABLES === */
table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: var(--space-lg);
    text-align: left;
    border-bottom: 1px solid var(--color-gray-300);
}

th {
    font-family: var(--font-ui);
    font-weight: 700;
    background: var(--gradient-subtle);
    color: var(--color-dark);
}

/* === DECORATIVE ELEMENTS === */
.pattern-dots {
    background-image: radial-gradient(circle, var(--color-gray-300) 1px, transparent 1px);
    background-size: 20px 20px;
}

.pattern-grid {
    background-image: linear-gradient(var(--color-gray-300) 1px, transparent 1px),
                      linear-gradient(90deg, var(--color-gray-300) 1px, transparent 1px);
    background-size: 20px 20px;
}

/* === ACCESSIBILITY === */
.visually-hidden-focusable:not(:focus):not(:focus-within) {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    :root {
        --focus-ring-width: 4px;
        --color-border: #000000;
    }

    .card {
        border-width: 2px;
    }

    .btn {
        border-width: 3px;
    }
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* === RESPONSIVE === */
@media (max-width: 768px) {
    .hero-section {
        padding: var(--space-2xl) 0;
    }

    .card-body {
        padding: var(--space-lg);
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}

/* === PRINT STYLES === */
@media print {
    .navbar,
    footer,
    .btn,
    .alert {
        display: none;
    }

    body {
        font-size: 12pt;
        color: #000;
        background: #fff;
    }

    a {
        text-decoration: underline;
        color: #000;
    }

    a[href^="http"]:after {
        content: " (" attr(href) ")";
    }
}

/* === UTILITY CLASSES === */
.text-gradient {
    background: var(--gradient-aurora);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glass {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.glow {
    box-shadow: var(--shadow-glow);
}

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

.text-primary {
    color: var(--color-primary) !important;
}

.bg-light {
    background: var(--bg-body) !important;
}