/* ==============================================
   DERS PLATFORMU - DARK THEME (GRAY/BLACK/PURPLE)
   Made by yefeblgn - No Blue Tones!
   ============================================== */

* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
    /* Dark Backgrounds */
    --bg-primary: #0a0a0f;
    --bg-secondary: #13131a;
    --bg-card: #16161f;
    --bg-tertiary: #1a1a24;
    
    /* Purple Accents */
    --purple-accent: #8b5cf6;
    --purple-light: #a78bfa;
    --purple-dark: #6d28d9;
    
    /* Grays */
    --gray-dark: #2a2a35;
    --gray-medium: #3f3f4f;
    --gray-light: #6b6b7b;
    --gray-lighter: #9a9aaa;
    
    /* Text */
    --text-primary: #e5e5ea;
    --text-secondary: #a0a0ab;
    --text-muted: #6b6b7b;
    
    /* Status */
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
    
    /* Borders & Shadows */
    --border: #2a2a35;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.6);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.6);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.7);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.8);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background: radial-gradient(circle at 20% 50%, rgba(139,92,246,0.03), transparent 50%),
                radial-gradient(circle at 80% 80%, rgba(139,92,246,0.03), transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1.5rem;
    position: relative;
    z-index: 1;
}

.main-content {
    position: relative;
    z-index: 1;
    min-height: calc(100vh - 200px);
}

/* Preloader */
.preloader {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999;
    transition: opacity 0.5s, visibility 0.5s;
}

.preloader.hidden { opacity: 0; visibility: hidden; }

.preloader-content { text-align: center; }

.spinner-ring {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border: 4px solid var(--gray-dark);
    border-top-color: var(--purple-accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.preloader-text {
    color: var(--text-secondary);
    font-size: 1.1rem;
    font-weight: 500;
}

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

/* Navbar */
.navbar {
    background: rgba(19,19,26,0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar .logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 1.25rem;
    font-weight: 700;
    transition: all 0.3s;
}

.navbar .logo i {
    font-size: 1.75rem;
    color: var(--purple-accent);
}

.navbar .logo:hover {
    color: var(--purple-light);
    transform: translateX(3px);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s;
    font-size: 0.9375rem;
    font-weight: 500;
}

.nav-item:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-admin {
    background: var(--purple-accent);
    color: white;
}

.nav-admin:hover {
    background: var(--purple-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(139,92,246,0.4);
}

.nav-logout { color: var(--error); }
.nav-logout:hover { background: rgba(239,68,68,0.1); }

.nav-user {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    color: var(--text-secondary);
}

.nav-user i {
    font-size: 1.25rem;
    color: var(--purple-accent);
}

/* Forms */
.form-group { margin-bottom: 1.5rem; }

.form-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.9375rem;
}

.form-group label i { color: var(--purple-accent); }

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.9375rem;
    transition: all 0.3s;
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--purple-accent);
    box-shadow: 0 0 0 3px rgba(139,92,246,0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 0.9375rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s;
    font-family: inherit;
}

.btn-primary {
    background: var(--purple-accent);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background: var(--purple-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-success { background: var(--success); color: white; }
.btn-success:hover { background: #059669; transform: translateY(-2px); }

.btn-danger { background: var(--error); color: white; }
.btn-danger:hover { background: #dc2626; }

.btn-info { background: var(--purple-light); color: white; }

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

.btn-block { width: 100%; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Alerts */
.alert {
    padding: 1rem 1.25rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-left: 4px solid;
}

.alert-success {
    background: rgba(16,185,129,0.1);
    border-color: var(--success);
    color: var(--success);
}

.alert-error {
    background: rgba(239,68,68,0.1);
    border-color: var(--error);
    color: var(--error);
}

.alert-info {
    background: rgba(167,139,250,0.1);
    border-color: var(--purple-light);
    color: var(--purple-light);
}

/* Auth Pages */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.auth-box {
    background: var(--bg-card);
    padding: 3rem;
    border-radius: 16px;
    box-shadow: var(--shadow-xl);
    width: 100%;
    max-width: 480px;
    border: 1px solid var(--border);
    position: relative;
}

.auth-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--purple-accent);
}

.auth-box h1 {
    margin-bottom: 2rem;
    color: var(--purple-accent);
    text-align: center;
    font-size: 2rem;
    font-weight: 700;
}

.auth-link {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--text-secondary);
}

.auth-link a {
    color: var(--purple-accent);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
}

.auth-link a:hover { color: var(--purple-light); }

/* Page Header */
.page-header {
    padding: 3rem 0;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    color: var(--purple-accent);
    margin-bottom: 0.8rem;
    font-weight: 800;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 1.2rem;
}

/* Courses Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    padding: 2rem 0;
}

.course-card {
    background: var(--bg-card);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all 0.4s;
    border: 1px solid var(--border);
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(139,92,246,0.3);
    border-color: var(--purple-accent);
}

.course-thumbnail {
    width: 100%;
    height: 200px;
    overflow: hidden;
    position: relative;
}

.course-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.course-card:hover .course-thumbnail img {
    transform: scale(1.1);
}

.course-thumbnail-default {
    background: linear-gradient(135deg, #2d1f3f, #4a3d5c);
    display: flex;
    align-items: center;
    justify-content: center;
}

.course-thumbnail-default i {
    font-size: 4rem;
    color: var(--purple-light);
}

.course-content { padding: 1.8rem; }

.course-content h3 {
    margin-bottom: 0.8rem;
    color: var(--text-primary);
    font-size: 1.3rem;
    font-weight: 700;
}

.course-description {
    color: var(--text-secondary);
    margin-bottom: 1.2rem;
    font-size: 0.95rem;
    line-height: 1.6;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--text-secondary);
}

.course-meta i { color: var(--purple-accent); }

.admin-quick-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.admin-quick-actions .btn {
    flex: 1;
    padding: 0.6rem;
    font-size: 0.85rem;
}

/* Admin Panel */
.admin-container { padding: 2rem 0; }

.admin-section {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.admin-section h2 {
    margin-bottom: 2rem;
    color: var(--purple-accent);
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.course-admin-item {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.course-admin-item:hover { border-color: var(--purple-accent); }

.course-admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.course-admin-header h3 {
    color: var(--text-primary);
    font-size: 1.4rem;
}

.course-admin-actions {
    display: flex;
    gap: 0.8rem;
    flex-wrap: wrap;
}

.materials-section {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border);
}

.material-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem;
    background: var(--bg-card);
    border-radius: 10px;
    margin-bottom: 0.8rem;
    border: 1px solid var(--border);
    transition: all 0.3s;
    flex-wrap: wrap;
    gap: 1rem;
}

.material-item:hover { border-color: var(--purple-accent); }

.material-info {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    flex-wrap: wrap;
}

.material-type {
    background: var(--purple-accent);
    color: white;
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

/* Course Detail */
.breadcrumb {
    padding: 1.5rem 0;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--purple-accent);
    text-decoration: none;
    transition: all 0.3s;
}

.breadcrumb a:hover { color: var(--purple-light); }

.course-header {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
}

.course-header h1 {
    color: var(--text-primary);
    margin-bottom: 0.8rem;
    font-size: 2.2rem;
    font-weight: 800;
}

.course-instructor {
    color: var(--purple-accent);
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
}

.course-layout {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 2rem;
}

.materials-sidebar {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.materials-sidebar h2 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.materials-list-view {
    max-height: calc(100vh - 300px);
    overflow-y: auto;
    padding-right: 0.5rem;
}

.material-list-item {
    display: flex;
    gap: 1rem;
    padding: 1.2rem;
    border-radius: 12px;
    margin-bottom: 0.8rem;
    cursor: pointer;
    transition: all 0.3s;
    border: 2px solid transparent;
    background: var(--bg-secondary);
}

.material-list-item:hover {
    background: var(--bg-tertiary);
    border-color: var(--border);
}

.material-list-item.active {
    background: rgba(139,92,246,0.1);
    border-color: var(--purple-accent);
}

.material-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    border-radius: 10px;
    background: var(--purple-accent);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.material-details {
    flex: 1;
    min-width: 0;
}

.material-details strong {
    display: block;
    margin-bottom: 0.4rem;
    color: var(--text-primary);
    word-wrap: break-word;
}

.material-details small {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.material-viewer {
    background: var(--bg-card);
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border);
    overflow: hidden;
}

.viewer-placeholder {
    height: calc(100vh - 200px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.placeholder-content { text-align: center; }

.placeholder-icon {
    font-size: 5rem;
    display: block;
    margin-bottom: 1.5rem;
    color: var(--purple-accent);
}

/* PDF Viewer */
.pdf-viewer {
    padding: 2rem;
    min-height: 600px;
}

.pdf-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border);
    flex-wrap: wrap;
    gap: 1rem;
}

.pdf-toolbar h3 {
    color: var(--text-primary);
    font-size: 1.2rem;
}

.pdf-controls {
    display: flex;
    gap: 0.8rem;
    align-items: center;
    flex-wrap: wrap;
}

.pdf-controls #page-info {
    color: var(--text-secondary);
    padding: 0.6rem 1.2rem;
    background: var(--bg-card);
    border-radius: 8px;
    font-weight: 600;
    border: 1px solid var(--border);
}

.pdf-canvas-container {
    max-height: calc(100vh - 300px);
    overflow-y: auto;
    display: flex;
    justify-content: center;
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: 12px;
    min-height: 400px;
}

#pdf-canvas {
    box-shadow: var(--shadow-xl);
    border-radius: 8px;
    background: white;
    max-width: 100%;
    height: auto;
}

/* PDF Fullscreen */
.pdf-viewer:fullscreen,
.pdf-viewer:-webkit-full-screen {
    background: var(--bg-primary);
    padding: 0;
}

.pdf-viewer:fullscreen .pdf-toolbar,
.pdf-viewer:-webkit-full-screen .pdf-toolbar {
    position: sticky;
    top: 0;
    z-index: 100;
    border-radius: 0;
    margin: 0;
}

.pdf-viewer:fullscreen .pdf-canvas-container,
.pdf-viewer:-webkit-full-screen .pdf-canvas-container {
    max-height: calc(100vh - 100px);
    margin: 0;
    border-radius: 0;
}

/* Video Player */
.video-viewer { padding: 2rem; }

.video-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 1px solid var(--border);
    flex-wrap: wrap;
    gap: 1rem;
}

.video-header h3 {
    color: var(--text-primary);
    font-size: 1.2rem;
}

.custom-video-player {
    position: relative;
    width: 100%;
    background: #000;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    cursor: default;
    transition: cursor 0.3s;
}

.custom-video-player.hide-cursor {
    cursor: none;
}

.custom-video-player.hide-cursor * {
    cursor: none !important;
}

.custom-video-player video {
    width: 100%;
    display: block;
}

.video-controls {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.95) 0%, rgba(0,0,0,0.7) 50%, transparent 100%);
    padding: 1.5rem 1rem 1rem;
    opacity: 0;
    transition: opacity 0.3s;
    z-index: 10;
}

.custom-video-player.show-controls .video-controls,
.custom-video-player.paused .video-controls {
    opacity: 1;
}

.progress-container {
    width: 100%;
    height: 6px;
    background: rgba(255,255,255,0.2);
    border-radius: 3px;
    cursor: pointer;
    margin-bottom: 0.75rem;
    transition: height 0.2s;
}

.progress-container:hover { height: 8px; }

.progress-bar {
    height: 100%;
    background: var(--purple-accent);
    border-radius: 3px;
    position: relative;
}

.progress-bar::after {
    content: '';
    position: absolute;
    right: -6px;
    top: 50%;
    transform: translateY(-50%);
    width: 14px;
    height: 14px;
    background: var(--purple-accent);
    border-radius: 50%;
    opacity: 0;
    transition: opacity 0.2s;
    box-shadow: 0 0 10px rgba(139,92,246,0.8);
}

.progress-container:hover .progress-bar::after { opacity: 1; }

.video-controls-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.video-controls-left,
.video-controls-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.video-control-btn {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 6px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
}

.video-control-btn:hover {
    background: rgba(255,255,255,0.2);
    transform: scale(1.1);
}

.video-control-btn.play-btn { font-size: 1.5rem; }

.video-time {
    color: white;
    font-size: 0.875rem;
    font-weight: 600;
    font-family: 'Courier New', monospace;
    min-width: 110px;
}

.volume-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.volume-slider {
    width: 0;
    opacity: 0;
    transition: all 0.3s;
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    background: rgba(255,255,255,0.3);
    border-radius: 2px;
    outline: none;
}

.volume-container:hover .volume-slider {
    width: 70px;
    opacity: 1;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 12px;
    height: 12px;
    background: var(--purple-accent);
    cursor: pointer;
    border-radius: 50%;
}

.volume-slider::-moz-range-thumb {
    width: 12px;
    height: 12px;
    background: var(--purple-accent);
    cursor: pointer;
    border-radius: 50%;
    border: none;
}

.speed-selector { position: relative; }
.speed-btn { min-width: 60px; font-size: 0.9rem; }

.speed-menu {
    position: absolute;
    bottom: 100%;
    right: 0;
    background: rgba(19,19,26,0.98);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(10px);
}

.speed-selector:hover .speed-menu,
.speed-menu.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.speed-option {
    display: block;
    width: 100%;
    padding: 0.5rem 1rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    text-align: left;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s;
    font-size: 0.9rem;
    font-weight: 500;
}

.speed-option:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.speed-option.active {
    background: var(--purple-accent);
    color: white;
}

.fullscreen-btn { font-size: 1.3rem; }

.video-watermark {
    position: absolute;
    bottom: 5rem;
    right: 1.5rem;
    background: rgba(0,0,0,0.7);
    color: rgba(255,255,255,0.6);
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    z-index: 5;
    backdrop-filter: blur(5px);
    transition: all 0.3s;
}

.video-watermark:hover {
    color: var(--purple-accent);
    background: rgba(0,0,0,0.85);
}

.video-watermark a {
    color: inherit;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

/* Double tap indicators for mobile */
.double-tap-indicator {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 100px;
    height: 100px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: transparent;
    color: white;
    opacity: 0;
    pointer-events: none;
    z-index: 15;
    transition: opacity 0.3s;
}

.double-tap-indicator.left {
    left: 15%;
}

.double-tap-indicator.right {
    right: 15%;
}

.double-tap-indicator.active {
    animation: doubleTapFade 0.6s ease-out;
}

.double-tap-indicator i {
    font-size: 3.5rem;
    margin-bottom: 0.3rem;
    filter: drop-shadow(0 2px 8px rgba(0,0,0,0.8));
}

.double-tap-indicator span {
    font-size: 1rem;
    font-weight: 700;
    text-shadow: 0 2px 8px rgba(0,0,0,0.8);
}

@keyframes doubleTapFade {
    0% {
        opacity: 0;
        transform: translateY(-50%) scale(0.5);
    }
    20% {
        opacity: 1;
        transform: translateY(-50%) scale(1.2);
    }
    40% {
        opacity: 0.9;
        transform: translateY(-50%) scale(1);
    }
    100% {
        opacity: 0;
        transform: translateY(-50%) scale(0.8);
    }
}

.video-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.custom-video-player.paused .video-overlay { opacity: 1; }

.video-play-icon {
    width: 90px;
    height: 90px;
    background: transparent;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
    transition: all 0.3s;
    cursor: pointer;
    pointer-events: all;
    filter: drop-shadow(0 4px 16px rgba(0,0,0,0.8));
}

.video-play-icon:hover {
    transform: scale(1.15);
    filter: drop-shadow(0 6px 20px rgba(139,92,246,0.6));
}

.video-play-icon i {
    filter: drop-shadow(0 2px 8px rgba(0,0,0,0.9));
}

.video-loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255,255,255,0.2);
    border-top-color: var(--purple-accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    opacity: 0;
    pointer-events: none;
}

.custom-video-player.loading .video-loading { opacity: 1; }

.custom-video-player:fullscreen,
.custom-video-player:-webkit-full-screen {
    border-radius: 0;
}

/* Footer */
.site-footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 3rem 0 1rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.footer-logo i {
    color: var(--purple-accent);
    font-size: 1.5rem;
}

.footer-desc {
    color: var(--text-secondary);
    line-height: 1.6;
}

.footer-center h4,
.footer-right h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

.footer-center ul { list-style: none; }

.footer-center ul li { margin-bottom: 0.5rem; }

.footer-center ul li a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-center ul li a:hover {
    color: var(--purple-accent);
    transform: translateX(3px);
}

.footer-right p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-social {
    display: flex;
    gap: 0.75rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 8px;
    transition: all 0.3s;
    text-decoration: none;
}

.footer-social a:hover {
    background: var(--purple-accent);
    color: white;
    transform: translateY(-2px);
}

.footer-bottom {
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.made-by {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.made-by i.fa-heart {
    color: var(--error);
    animation: heartbeat 1.5s ease-in-out infinite;
}

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.creator-link {
    color: var(--purple-accent);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
}

.creator-link:hover {
    color: var(--purple-light);
    text-decoration: underline;
}

/* Upload Progress */
.upload-progress {
    display: none;
    margin-top: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: 8px;
    border: 1px solid var(--border);
}

.upload-progress.active { display: block; }

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.progress-percentage {
    color: var(--purple-accent);
    font-weight: 700;
}

.progress-bar-container {
    width: 100%;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: var(--purple-accent);
    border-radius: 4px;
    transition: width 0.3s;
    position: relative;
}

.progress-bar-fill::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* Scrollbar */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb {
    background: var(--gray-medium);
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover { background: var(--purple-accent); }

/* Utility */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--bg-card);
    border-radius: 16px;
    border: 2px dashed var(--border);
}

.no-materials {
    text-align: center;
    padding: 3rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 2px dashed var(--border);
    color: var(--text-secondary);
}

.material-form {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 12px;
    margin-bottom: 2rem;
    border: 1px solid var(--border);
}

.document-viewer { padding: 3rem; }

.document-header {
    margin-bottom: 2rem;
    text-align: center;
}

.document-header h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
}

.document-content {
    text-align: center;
    padding: 4rem 2rem;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 2px dashed var(--border);
}

.document-icon {
    font-size: 5rem;
    margin-bottom: 1.5rem;
    color: var(--purple-accent);
}

.document-content p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Mobile Responsive */
@media (max-width: 1024px) {
    .course-layout {
        grid-template-columns: 1fr;
    }
    
    .materials-sidebar {
        position: static;
    }
}

@media (max-width: 768px) {
    .container { padding: 0 1rem; }
    
    .nav-item span,
    .nav-user span { display: none; }
    
    .nav-item { padding: 0.5rem; }
    
    .form-row { grid-template-columns: 1fr; }
    
    .auth-box { padding: 2rem; }
    
    .page-header h1 { font-size: 2rem; }
    .page-header p { font-size: 1rem; }
    
    .courses-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .admin-section { padding: 1.5rem; }
    
    .course-admin-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .pdf-viewer { padding: 1rem; }
    .pdf-canvas-container { padding: 1rem; }
    
    .video-viewer { padding: 1rem; }
    
    .video-controls { 
        padding: 0.75rem 0.5rem 0.5rem;
    }
    
    .video-controls-wrapper {
        gap: 0.5rem;
    }
    
    .video-controls-left,
    .video-controls-right {
        gap: 0.5rem;
    }
    
    .video-time {
        font-size: 0.7rem;
        min-width: 75px;
        white-space: nowrap;
    }
    
    /* Mobilde volume kontrolü gizle (sistem kontrolü kullanılsın) */
    .volume-container {
        display: none;
    }
    
    .speed-btn {
        min-width: 38px;
        font-size: 0.75rem;
        padding: 0.4rem 0.5rem;
    }
    
    .video-watermark {
        bottom: 4.5rem;
        right: 0.75rem;
        font-size: 0.65rem;
        padding: 0.35rem 0.5rem;
    }
    
    .video-control-btn {
        padding: 0.35rem;
        font-size: 0.95rem;
    }
    
    .video-control-btn.play-btn { 
        font-size: 1.2rem;
        padding: 0.4rem 0.5rem;
    }
    
    .video-play-icon {
        width: 60px;
        height: 60px;
        font-size: 1.8rem;
    }
    
    /* Skip buttons mobilde gizle */
    .skip-back,
    .skip-forward {
        display: none;
    }
    
    /* Progress bar mobilde daha kalın */
    .progress-container {
        height: 8px;
        margin-bottom: 0.5rem;
    }
    
    .progress-container:hover {
        height: 8px;
    }
    
    /* Speed menu */
    .speed-menu {
        right: 0;
        min-width: 90px;
    }
    
    .speed-option {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
    
    .footer-content { grid-template-columns: 1fr; }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .admin-quick-actions { flex-direction: column; }
    .course-meta {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    /* Extra mobil optimizasyonlar */
    .video-controls {
        padding: 0.5rem 0.35rem 0.35rem;
    }
    
    .video-time {
        font-size: 0.65rem;
        min-width: 65px;
    }
    
    .video-control-btn {
        padding: 0.3rem;
        font-size: 0.85rem;
    }
    
    .video-control-btn.play-btn {
        font-size: 1.1rem;
        padding: 0.35rem 0.4rem;
    }
    
    .speed-btn {
        min-width: 32px;
        font-size: 0.7rem;
        padding: 0.35rem 0.4rem;
    }
    
    .fullscreen-btn {
        font-size: 1rem;
    }
    
    .video-watermark {
        font-size: 0.6rem;
        padding: 0.3rem 0.4rem;
        bottom: 4rem;
        right: 0.5rem;
    }
    
    .progress-container {
        height: 10px;
    }
}