/* ============================================
   BlockStar Academy - Dark Theme
   ============================================ */

:root {
    /* Core palette */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a28;
    --bg-card: #14141f;
    --bg-card-hover: #1c1c2e;
    --bg-input: #1a1a28;
    --bg-overlay: rgba(0,0,0,0.7);

    /* Borders */
    --border-color: #2a2a3d;
    --border-light: #1f1f30;
    --border-focus: #6366f1;

    /* Text */
    --text-primary: #e8e8ed;
    --text-secondary: #9595a8;
    --text-muted: #6b6b80;
    --text-accent: #a5b4fc;

    /* Accents */
    --accent: #6366f1;
    --accent-hover: #818cf8;
    --accent-glow: rgba(99,102,241,0.15);
    --accent-soft: rgba(99,102,241,0.1);

    /* Status */
    --success: #34d399;
    --success-bg: rgba(52,211,153,0.1);
    --warning: #fbbf24;
    --warning-bg: rgba(251,191,36,0.1);
    --danger: #f87171;
    --danger-bg: rgba(248,113,113,0.1);
    --info: #60a5fa;
    --info-bg: rgba(96,165,250,0.1);

    /* Difficulty badges */
    --beginner: #34d399;
    --intermediate: #fbbf24;
    --advanced: #f87171;

    /* Typography */
    --font-display: 'Outfit', sans-serif;
    --font-body: 'Outfit', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Spacing & Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 30px rgba(99,102,241,0.15);

    /* Layout */
    --nav-height: 64px;
    --container-max: 1280px;
    --sidebar-width: 300px;
}

/* ---- Reset & Base ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}
a { color: var(--text-accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-hover); }
img { max-width: 100%; display: block; }
input, textarea, select, button { font-family: inherit; font-size: inherit; }

.container { max-width: var(--container-max); margin: 0 auto; padding: 0 1.5rem; }
.icon-sm { width: 16px; height: 16px; display: inline-block; vertical-align: middle; }
.icon-md { width: 20px; height: 20px; }
.icon-lg { width: 24px; height: 24px; }

/* ---- Navigation ---- */
.nav-main {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: rgba(10,10,15,0.85); backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    height: var(--nav-height);
}
.nav-inner {
    max-width: var(--container-max); margin: 0 auto; padding: 0 1.5rem;
    display: flex; align-items: center; justify-content: space-between;
    height: 100%;
}
.nav-logo { display: flex; align-items: center; gap: 0.6rem; }
.logo-text { font-weight: 700; font-size: 1.15rem; color: var(--text-primary); letter-spacing: -0.02em; }
.logo-accent { color: var(--accent); }
.nav-links { display: flex; gap: 0.25rem; }
.nav-link {
    padding: 0.5rem 0.85rem; border-radius: var(--radius-sm);
    color: var(--text-secondary); font-size: 0.9rem; font-weight: 500;
    transition: all 0.2s;
}
.nav-link:hover { color: var(--text-primary); background: var(--accent-soft); }
.nav-actions { display: flex; align-items: center; gap: 0.5rem; }
.nav-avatar {
    width: 36px; height: 36px; border-radius: var(--radius-full);
    background: var(--accent); border: none; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    color: white; font-weight: 600; font-size: 0.8rem;
}
.nav-user-menu { position: relative; }
.dropdown-menu {
    display: none; position: absolute; top: calc(100% + 8px); right: 0;
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-md); min-width: 220px; padding: 0.5rem;
    box-shadow: var(--shadow-lg); z-index: 200;
}
.dropdown-menu.show { display: block; }
.dropdown-header { padding: 0.75rem; border-bottom: 1px solid var(--border-light); margin-bottom: 0.25rem; }
.dropdown-header strong { display: block; color: var(--text-primary); font-size: 0.9rem; }
.dropdown-header small { color: var(--text-muted); font-size: 0.8rem; }
.dropdown-item {
    display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm); color: var(--text-secondary); font-size: 0.875rem;
    border: none; background: none; width: 100%; cursor: pointer; text-align: left;
}
.dropdown-item:hover { background: var(--accent-soft); color: var(--text-primary); }
.dropdown-divider { height: 1px; background: var(--border-light); margin: 0.25rem 0; }
.text-danger { color: var(--danger) !important; }
.nav-mobile-toggle { display: none; background: none; border: none; color: var(--text-primary); cursor: pointer; }
.mobile-menu { display: none; flex-direction: column; padding: 1rem 1.5rem; gap: 0.5rem; background: var(--bg-secondary); border-bottom: 1px solid var(--border-color); }
.mobile-menu.show { display: flex; }
.mobile-menu a, .mobile-menu button { padding: 0.6rem 0; color: var(--text-secondary); font-size: 0.95rem; background: none; border: none; cursor: pointer; text-align: left; }

@media (max-width: 768px) {
    .nav-links, .nav-actions { display: none; }
    .nav-mobile-toggle { display: block; }
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem;
    padding: 0.6rem 1.25rem; border-radius: var(--radius-sm); font-weight: 600;
    font-size: 0.875rem; border: none; cursor: pointer; transition: all 0.2s;
    text-decoration: none; line-height: 1.4;
}
.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: var(--accent-hover); color: white; box-shadow: var(--shadow-glow); }
.btn-secondary { background: var(--bg-tertiary); color: var(--text-primary); border: 1px solid var(--border-color); }
.btn-secondary:hover { background: var(--bg-card-hover); border-color: var(--accent); }
.btn-ghost { background: transparent; color: var(--text-secondary); }
.btn-ghost:hover { color: var(--text-primary); background: var(--accent-soft); }
.btn-danger { background: var(--danger); color: white; }
.btn-success { background: var(--success); color: #0a0a0f; }
.btn-lg { padding: 0.8rem 1.75rem; font-size: 1rem; border-radius: var(--radius-md); }
.btn-sm { padding: 0.35rem 0.75rem; font-size: 0.8rem; }
.btn-block { width: 100%; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-icon { padding: 0.5rem; }

/* ---- Cards ---- */
.card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); overflow: hidden; transition: all 0.3s;
}
.card:hover { border-color: rgba(99,102,241,0.3); box-shadow: var(--shadow-glow); transform: translateY(-2px); }
.card-body { padding: 1.25rem; }
.card-footer { padding: 1rem 1.25rem; border-top: 1px solid var(--border-light); }

/* ---- Course Card ---- */
.course-card { display: flex; flex-direction: column; }
.course-card .card-thumb {
    position: relative; aspect-ratio: 16/9; background: var(--bg-tertiary);
    overflow: hidden; display: flex; align-items: center; justify-content: center;
}
.course-card .card-thumb .thumb-placeholder {
    font-size: 2.5rem; opacity: 0.15;
}
.course-card .card-thumb img { width: 100%; height: 100%; object-fit: cover; }
.course-card .difficulty-badge {
    position: absolute; top: 0.75rem; left: 0.75rem;
    padding: 0.2rem 0.6rem; border-radius: var(--radius-full);
    font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em;
}
.badge-beginner { background: rgba(52,211,153,0.15); color: var(--beginner); }
.badge-intermediate { background: rgba(251,191,36,0.15); color: var(--intermediate); }
.badge-advanced { background: rgba(248,113,113,0.15); color: var(--advanced); }
.course-card .card-body { flex: 1; display: flex; flex-direction: column; gap: 0.5rem; }
.course-card .card-category { font-size: 0.75rem; color: var(--accent); font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; }
.course-card .card-title { font-size: 1.05rem; font-weight: 600; color: var(--text-primary); line-height: 1.3; }
.course-card .card-desc { font-size: 0.85rem; color: var(--text-muted); line-height: 1.5; flex: 1; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.course-card .card-meta { display: flex; align-items: center; gap: 1rem; font-size: 0.8rem; color: var(--text-muted); margin-top: 0.5rem; }
.course-card .card-meta span { display: flex; align-items: center; gap: 0.3rem; }
.course-card .card-instructor { display: flex; align-items: center; gap: 0.5rem; font-size: 0.8rem; color: var(--text-secondary); padding-top: 0.75rem; border-top: 1px solid var(--border-light); margin-top: auto; }
.course-card .instructor-avatar { width: 24px; height: 24px; border-radius: var(--radius-full); background: var(--accent-soft); display: flex; align-items: center; justify-content: center; font-size: 0.65rem; color: var(--accent); font-weight: 700; }

/* ---- Forms ---- */
.form-group { margin-bottom: 1.25rem; }
.form-label { display: block; font-size: 0.85rem; font-weight: 500; color: var(--text-secondary); margin-bottom: 0.4rem; }
.form-input, .form-select, .form-textarea {
    width: 100%; padding: 0.65rem 0.85rem; background: var(--bg-input);
    border: 1px solid var(--border-color); border-radius: var(--radius-sm);
    color: var(--text-primary); font-size: 0.9rem; transition: border-color 0.2s;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
    outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft);
}
.form-textarea { min-height: 100px; resize: vertical; }
.form-error { color: var(--danger); font-size: 0.8rem; margin-top: 0.25rem; }
.form-help { color: var(--text-muted); font-size: 0.8rem; margin-top: 0.25rem; }
.form-check { display: flex; align-items: center; gap: 0.5rem; }
.form-check input[type="checkbox"] { accent-color: var(--accent); width: 16px; height: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
@media (max-width: 640px) { .form-row { grid-template-columns: 1fr; } }

/* ---- Badges ---- */
.badge {
    display: inline-flex; align-items: center; padding: 0.2rem 0.6rem;
    border-radius: var(--radius-full); font-size: 0.75rem; font-weight: 600;
}
.badge-primary { background: var(--accent-soft); color: var(--accent); }
.badge-success { background: var(--success-bg); color: var(--success); }
.badge-warning { background: var(--warning-bg); color: var(--warning); }
.badge-danger { background: var(--danger-bg); color: var(--danger); }

/* ---- Toast Notifications ---- */
.toast {
    position: fixed; top: calc(var(--nav-height) + 1rem); right: 1.5rem; z-index: 300;
    display: flex; align-items: center; gap: 0.75rem; padding: 0.85rem 1.25rem;
    border-radius: var(--radius-md); font-size: 0.9rem; font-weight: 500;
    animation: slideIn 0.3s ease;
}
.toast-success { background: #065f46; color: #d1fae5; border: 1px solid #059669; }
.toast-error { background: #7f1d1d; color: #fecaca; border: 1px solid #dc2626; }
.toast-warning { background: #78350f; color: #fef3c7; border: 1px solid #d97706; }
.toast-info { background: #1e3a5f; color: #bfdbfe; border: 1px solid #3b82f6; }
.toast-close { background: none; border: none; color: inherit; cursor: pointer; font-size: 1.2rem; opacity: 0.7; margin-left: 0.5rem; }
@keyframes slideIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }

/* ---- Progress Bar ---- */
.progress-bar { height: 6px; background: var(--bg-tertiary); border-radius: var(--radius-full); overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-hover)); border-radius: var(--radius-full); transition: width 0.5s ease; }

/* ---- Stat Cards ---- */
.stat-card {
    background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-lg);
    padding: 1.5rem; display: flex; flex-direction: column; gap: 0.5rem;
}
.stat-card .stat-value { font-size: 2rem; font-weight: 700; color: var(--text-primary); letter-spacing: -0.02em; }
.stat-card .stat-label { font-size: 0.85rem; color: var(--text-muted); }
.stat-card .stat-icon { width: 40px; height: 40px; border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; margin-bottom: 0.5rem; }

/* ---- Grids ---- */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }
@media (max-width: 1024px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

/* ---- Section Styles ---- */
.section { padding: 4rem 0; }
.section-sm { padding: 2rem 0; }
.section-header { margin-bottom: 2.5rem; }
.section-title { font-size: 1.75rem; font-weight: 700; color: var(--text-primary); letter-spacing: -0.02em; }
.section-subtitle { font-size: 1rem; color: var(--text-muted); margin-top: 0.5rem; max-width: 600px; }

/* ---- Hero ---- */
.hero {
    padding: calc(var(--nav-height) + 4rem) 0 4rem;
    background: radial-gradient(ellipse at 30% 0%, rgba(99,102,241,0.08) 0%, transparent 60%),
                radial-gradient(ellipse at 70% 100%, rgba(99,102,241,0.05) 0%, transparent 60%),
                var(--bg-primary);
    position: relative; overflow: hidden;
}
.hero-content { max-width: 700px; }
.hero-badge {
    display: inline-flex; align-items: center; gap: 0.5rem; padding: 0.4rem 1rem;
    background: var(--accent-soft); border: 1px solid rgba(99,102,241,0.2);
    border-radius: var(--radius-full); font-size: 0.8rem; color: var(--accent);
    font-weight: 500; margin-bottom: 1.5rem;
}
.hero h1 {
    font-family: var(--font-display); font-size: clamp(2.5rem, 5vw, 3.75rem);
    font-weight: 800; line-height: 1.1; letter-spacing: -0.03em;
    color: var(--text-primary); margin-bottom: 1.25rem;
}
.hero h1 .gradient-text {
    background: linear-gradient(135deg, #818cf8 0%, #6366f1 50%, #a78bfa 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero p { font-size: 1.15rem; color: var(--text-secondary); line-height: 1.7; margin-bottom: 2rem; max-width: 560px; }
.hero-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.hero-stats {
    display: flex; gap: 2.5rem; margin-top: 3rem; padding-top: 2rem;
    border-top: 1px solid var(--border-light);
}
.hero-stat-value { font-size: 1.75rem; font-weight: 700; color: var(--text-primary); }
.hero-stat-label { font-size: 0.85rem; color: var(--text-muted); }

/* ---- Auth Pages ---- */
.auth-page {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    padding: calc(var(--nav-height) + 2rem) 1.5rem 2rem;
    background: radial-gradient(ellipse at 50% 0%, rgba(99,102,241,0.06) 0%, transparent 60%);
}
.auth-card {
    width: 100%; max-width: 440px; background: var(--bg-card);
    border: 1px solid var(--border-color); border-radius: var(--radius-xl);
    padding: 2.5rem;
}
.auth-card h1 { font-size: 1.5rem; font-weight: 700; margin-bottom: 0.5rem; text-align: center; }
.auth-card .auth-subtitle { text-align: center; color: var(--text-muted); margin-bottom: 2rem; font-size: 0.9rem; }

/* ---- Dashboard Layout ---- */
.dash-page { padding-top: var(--nav-height); min-height: 100vh; }
.dash-header {
    background: var(--bg-secondary); border-bottom: 1px solid var(--border-color);
    padding: 2rem 0;
}
.dash-header h1 { font-size: 1.5rem; font-weight: 700; }
.dash-header p { color: var(--text-muted); font-size: 0.9rem; margin-top: 0.25rem; }
.dash-content { padding: 2rem 0; }
.dash-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin-bottom: 2rem; }

/* ---- Learning Interface ---- */
.learn-layout {
    display: grid; grid-template-columns: var(--sidebar-width) 1fr; min-height: calc(100vh - var(--nav-height));
    padding-top: var(--nav-height);
}
.learn-sidebar {
    background: var(--bg-secondary); border-right: 1px solid var(--border-color);
    overflow-y: auto; height: calc(100vh - var(--nav-height)); position: sticky; top: var(--nav-height);
}
.learn-sidebar-header { padding: 1.25rem; border-bottom: 1px solid var(--border-color); }
.learn-sidebar-header h3 { font-size: 0.95rem; font-weight: 600; line-height: 1.3; }
.learn-sidebar-header .progress-info { display: flex; justify-content: space-between; font-size: 0.8rem; color: var(--text-muted); margin-top: 0.75rem; margin-bottom: 0.4rem; }
.module-group { border-bottom: 1px solid var(--border-light); }
.module-title {
    padding: 0.85rem 1.25rem; font-size: 0.8rem; font-weight: 600;
    color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em;
    background: var(--bg-tertiary);
}
.lesson-link {
    display: flex; align-items: center; gap: 0.65rem; padding: 0.65rem 1.25rem;
    font-size: 0.85rem; color: var(--text-secondary); transition: all 0.2s;
    border-left: 3px solid transparent;
}
.lesson-link:hover { background: var(--accent-soft); color: var(--text-primary); }
.lesson-link.active { background: var(--accent-soft); color: var(--accent); border-left-color: var(--accent); }
.lesson-link.completed { color: var(--success); }
.lesson-link .lesson-check { width: 18px; height: 18px; border-radius: var(--radius-full); border: 2px solid var(--border-color); display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.lesson-link.completed .lesson-check { background: var(--success); border-color: var(--success); }
.lesson-link.active .lesson-check { border-color: var(--accent); }
.learn-content { padding: 2.5rem; overflow-y: auto; }
.learn-content-inner { max-width: 800px; margin: 0 auto; }

@media (max-width: 900px) {
    .learn-layout { grid-template-columns: 1fr; }
    .learn-sidebar { position: static; height: auto; max-height: 50vh; }
}

/* ---- Lesson Content ---- */
.lesson-content { line-height: 1.8; color: var(--text-secondary); }
.lesson-content h2, .lesson-content h3, .lesson-content h4 { color: var(--text-primary); margin: 1.5em 0 0.75em; font-weight: 600; }
.lesson-content h3 { font-size: 1.3rem; }
.lesson-content h4 { font-size: 1.1rem; }
.lesson-content p { margin-bottom: 1em; }
.lesson-content strong { color: var(--text-primary); }
.lesson-content code { font-family: var(--font-mono); background: var(--bg-tertiary); padding: 0.15em 0.4em; border-radius: 4px; font-size: 0.9em; color: var(--accent-hover); }
.lesson-content pre { background: var(--bg-tertiary); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 1.25rem; overflow-x: auto; margin: 1.25em 0; }
.lesson-content pre code { background: none; padding: 0; }
.lesson-content blockquote { border-left: 3px solid var(--accent); background: var(--accent-soft); padding: 1rem 1.25rem; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 1.25em 0; color: var(--text-primary); }
.lesson-content ul, .lesson-content ol { padding-left: 1.5em; margin-bottom: 1em; }
.lesson-content li { margin-bottom: 0.4em; }
.lesson-nav { display: flex; justify-content: space-between; align-items: center; margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border-color); }

/* ---- Chat Interface ---- */
.chat-container { display: flex; flex-direction: column; height: calc(100vh - var(--nav-height)); padding-top: var(--nav-height); }
.chat-header { padding: 1rem 1.5rem; background: var(--bg-secondary); border-bottom: 1px solid var(--border-color); display: flex; align-items: center; gap: 0.75rem; }
.chat-messages { flex: 1; overflow-y: auto; padding: 1.5rem; display: flex; flex-direction: column; gap: 1rem; }
.chat-msg { max-width: 80%; padding: 0.85rem 1.15rem; border-radius: var(--radius-lg); font-size: 0.9rem; line-height: 1.6; }
.chat-msg.user { background: var(--accent); color: white; align-self: flex-end; border-bottom-right-radius: 4px; }
.chat-msg.assistant { background: var(--bg-tertiary); color: var(--text-primary); align-self: flex-start; border-bottom-left-radius: 4px; border: 1px solid var(--border-color); }
.chat-input-area { padding: 1rem 1.5rem; background: var(--bg-secondary); border-top: 1px solid var(--border-color); display: flex; gap: 0.75rem; }
.chat-input-area input { flex: 1; }
.chat-input-area form { display: flex; gap: 0.75rem; width: 100%; }

/* ---- Certificate Card ---- */
.cert-card { display: flex; align-items: center; gap: 1.25rem; padding: 1.25rem; }
.cert-icon { width: 50px; height: 50px; border-radius: var(--radius-md); background: linear-gradient(135deg, rgba(99,102,241,0.2), rgba(167,139,250,0.2)); display: flex; align-items: center; justify-content: center; color: var(--accent); flex-shrink: 0; }
.cert-info { flex: 1; }
.cert-info h4 { font-size: 0.95rem; font-weight: 600; color: var(--text-primary); }
.cert-info p { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.2rem; }
.cert-actions { display: flex; gap: 0.5rem; }

/* ---- Tables ---- */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th { text-align: left; padding: 0.75rem 1rem; font-weight: 600; color: var(--text-muted); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; border-bottom: 1px solid var(--border-color); }
td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--border-light); color: var(--text-secondary); }
tr:hover td { background: var(--accent-soft); }

/* ---- Pagination ---- */
.pagination { display: flex; justify-content: center; gap: 0.25rem; margin-top: 2rem; }
.pagination a, .pagination span { padding: 0.4rem 0.8rem; border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--text-muted); border: 1px solid var(--border-color); }
.pagination a:hover { background: var(--accent-soft); color: var(--text-primary); }
.pagination .active { background: var(--accent); color: white; border-color: var(--accent); }

/* ---- Empty State ---- */
.empty-state { text-align: center; padding: 4rem 2rem; }
.empty-state .empty-icon { font-size: 3rem; opacity: 0.15; margin-bottom: 1rem; }
.empty-state h3 { font-size: 1.1rem; color: var(--text-primary); margin-bottom: 0.5rem; }
.empty-state p { color: var(--text-muted); font-size: 0.9rem; max-width: 400px; margin: 0 auto; }

/* ---- Verify Page ---- */
.verify-result { padding: 2rem; border-radius: var(--radius-lg); margin-top: 2rem; }
.verify-valid { background: var(--success-bg); border: 1px solid rgba(52,211,153,0.3); }
.verify-invalid { background: var(--danger-bg); border: 1px solid rgba(248,113,113,0.3); }
.verify-result h3 { font-size: 1.2rem; margin-bottom: 1rem; }
.verify-detail { display: flex; justify-content: space-between; padding: 0.5rem 0; border-bottom: 1px solid rgba(255,255,255,0.05); font-size: 0.9rem; }
.verify-detail .label { color: var(--text-muted); }
.verify-detail .value { color: var(--text-primary); font-weight: 500; }

/* ---- Admin Sidebar ---- */
.admin-layout { display: grid; grid-template-columns: 240px 1fr; min-height: calc(100vh - var(--nav-height)); padding-top: var(--nav-height); }
.admin-sidebar {
    background: var(--bg-secondary); border-right: 1px solid var(--border-color);
    padding: 1.5rem 0; position: sticky; top: var(--nav-height); height: calc(100vh - var(--nav-height)); overflow-y: auto;
}
.admin-sidebar .sidebar-section { padding: 0 0.75rem; margin-bottom: 1.5rem; }
.admin-sidebar .sidebar-label { font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); padding: 0 0.75rem; margin-bottom: 0.5rem; }
.admin-sidebar a {
    display: flex; align-items: center; gap: 0.6rem; padding: 0.55rem 0.75rem;
    border-radius: var(--radius-sm); color: var(--text-secondary); font-size: 0.875rem;
    font-weight: 500; transition: all 0.2s;
}
.admin-sidebar a:hover { background: var(--accent-soft); color: var(--text-primary); }
.admin-sidebar a.active { background: var(--accent-soft); color: var(--accent); }
.admin-content { padding: 2rem; }

@media (max-width: 900px) {
    .admin-layout { grid-template-columns: 1fr; }
    .admin-sidebar { position: static; height: auto; }
}

/* ---- Instructor Card ---- */
.instructor-card { text-align: center; padding: 2rem 1.5rem; }
.instructor-card .instructor-avatar-lg {
    width: 80px; height: 80px; border-radius: var(--radius-full);
    background: linear-gradient(135deg, var(--accent), #a78bfa);
    display: flex; align-items: center; justify-content: center;
    font-size: 1.5rem; font-weight: 700; color: white; margin: 0 auto 1rem;
}
.instructor-card h3 { font-size: 1.1rem; font-weight: 600; }
.instructor-card .instructor-title { font-size: 0.85rem; color: var(--accent); margin-top: 0.25rem; }
.instructor-card .instructor-specialty { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.5rem; }
.instructor-card .instructor-stats { display: flex; justify-content: center; gap: 2rem; margin-top: 1rem; padding-top: 1rem; border-top: 1px solid var(--border-light); }
.instructor-card .instructor-stats span { font-size: 0.8rem; color: var(--text-muted); }
.instructor-card .instructor-stats strong { color: var(--text-primary); }

/* ---- Tab Navigation ---- */
.tabs { display: flex; gap: 0.25rem; border-bottom: 1px solid var(--border-color); margin-bottom: 1.5rem; }
.tab-link { padding: 0.65rem 1rem; font-size: 0.875rem; font-weight: 500; color: var(--text-muted); border-bottom: 2px solid transparent; transition: all 0.2s; text-decoration: none; }
.tab-link:hover { color: var(--text-primary); }
.tab-link.active { color: var(--accent); border-bottom-color: var(--accent); }

/* ---- Footer ---- */
.footer { margin-top: 4rem; padding: 3rem 0; background: var(--bg-secondary); border-top: 1px solid var(--border-color); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem; margin-bottom: 2rem; }
.footer-desc { color: var(--text-muted); font-size: 0.85rem; line-height: 1.6; margin-top: 0.75rem; max-width: 320px; }
.footer-heading { font-size: 0.8rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-primary); margin-bottom: 0.75rem; }
.footer a { display: block; color: var(--text-muted); font-size: 0.85rem; padding: 0.25rem 0; transition: color 0.2s; }
.footer a:hover { color: var(--accent); }
.footer-bottom { padding-top: 1.5rem; border-top: 1px solid var(--border-light); }
.footer-bottom p { font-size: 0.8rem; color: var(--text-muted); }
@media (max-width: 768px) { .footer-grid { grid-template-columns: 1fr; gap: 2rem; } }

/* ---- Utilities ---- */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-muted { color: var(--text-muted); }
.text-accent { color: var(--accent); }
.text-success { color: var(--success); }
.text-sm { font-size: 0.85rem; }
.text-xs { font-size: 0.75rem; }
.mt-1 { margin-top: 0.5rem; } .mt-2 { margin-top: 1rem; } .mt-3 { margin-top: 1.5rem; } .mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; } .mb-2 { margin-bottom: 1rem; } .mb-3 { margin-bottom: 1.5rem; }
.flex { display: flex; } .flex-between { display: flex; justify-content: space-between; align-items: center; }
.gap-1 { gap: 0.5rem; } .gap-2 { gap: 1rem; }
.hidden { display: none; }

/* ============================================
   Engagement Features — Gamification, Notes,
   Bookmarks, Discussions, Knowledge Checks
   ============================================ */

/* Streak Display */
.streak-display { display: flex; align-items: center; gap: 0.75rem; background: var(--bg-tertiary); padding: 0.75rem 1.25rem; border-radius: var(--radius-lg); border: 1px solid var(--border-color); }
.streak-flame { font-size: 2rem; line-height: 1; }
.streak-count { font-size: 1.5rem; font-weight: 700; color: var(--warning); line-height: 1.2; }
.streak-label { font-size: 0.75rem; color: var(--text-muted); }

/* XP Bar */
.gamification-bar { background: var(--bg-card); border: 1px solid var(--border-color); }
.gam-stat { text-align: center; }
.gam-label { display: block; font-size: 0.7rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
.gam-value { display: block; font-size: 1.1rem; font-weight: 700; color: var(--text-primary); }
.xp-fill { background: linear-gradient(90deg, #6366f1, #a5b4fc) !important; }

/* Heatmap */
.heatmap { overflow-x: auto; padding-bottom: 0.25rem; }
.heatmap-cell { width: 12px; height: 12px; border-radius: 2px; display: inline-block; cursor: default; }

/* Achievement Badge (inline) */
.achievement-badge { display: inline-flex; align-items: center; gap: 0.4rem; padding: 0.4rem 0.75rem; border-radius: var(--radius-full); font-size: 0.8rem; font-weight: 500; background: var(--bg-tertiary); border: 1px solid var(--border-color); color: var(--text-muted); }
.achievement-badge.earned { border-color: var(--badge-color, var(--accent)); color: var(--badge-color, var(--accent)); background: color-mix(in srgb, var(--badge-color, var(--accent)) 10%, transparent); }
.achievement-badge i { width: 14px; height: 14px; }

/* Achievement Card */
.achievement-card { transition: all 0.2s; }
.achievement-card.locked { opacity: 0.5; }
.achievement-card.earned { border-color: var(--border-focus); }
.achievement-icon { width: 48px; height: 48px; border-radius: var(--radius-md); display: flex; align-items: center; justify-content: center; background: color-mix(in srgb, var(--badge-color) 15%, transparent); color: var(--badge-color); flex-shrink: 0; }

/* Note Panel */
.note-panel { position: fixed; top: var(--nav-height); right: -360px; width: 350px; height: calc(100vh - var(--nav-height)); background: var(--bg-secondary); border-left: 1px solid var(--border-color); z-index: 50; transition: right 0.3s ease; overflow-y: auto; box-shadow: var(--shadow-lg); }
.note-panel.show { right: 0; }
.note-panel-header { padding: 1rem 0.75rem; border-bottom: 1px solid var(--border-color); }
.note-item { padding: 0.75rem; border-bottom: 1px solid var(--border-light); }
.note-content { font-size: 0.85rem; color: var(--text-secondary); white-space: pre-wrap; margin-bottom: 0.4rem; }

/* Discussion */
.discussion-section { }
.discussion-item { padding: 1rem 0; border-bottom: 1px solid var(--border-light); }
.discussion-meta { display: flex; gap: 0.5rem; align-items: center; margin-bottom: 0.35rem; }
.discussion-meta strong { font-size: 0.85rem; }
.discussion-body { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }
.discussion-reply { margin-left: 1.5rem; padding: 0.75rem 0 0 1rem; border-left: 2px solid var(--border-light); margin-top: 0.5rem; }
.reply-form { margin-top: 0.5rem; display: flex; gap: 0.5rem; }
.reply-form input { flex: 1; }
.reply-form input::placeholder { font-size: 0.8rem; }

/* Knowledge Checks */
.kc-card { background: var(--bg-tertiary); border: 1px solid var(--border-color); border-radius: var(--radius-md); padding: 1.25rem; margin-bottom: 1rem; }
.kc-question { font-weight: 600; font-size: 0.95rem; margin-bottom: 0.75rem; }
.kc-options { display: grid; gap: 0.5rem; }
.kc-option { display: block; width: 100%; text-align: left; padding: 0.65rem 1rem; background: var(--bg-card); border: 1px solid var(--border-color); border-radius: var(--radius-sm); color: var(--text-secondary); font-size: 0.875rem; cursor: pointer; transition: all 0.2s; }
.kc-option:hover:not(:disabled) { border-color: var(--accent); color: var(--text-primary); }
.kc-option.correct { border-color: var(--success) !important; background: var(--success-bg) !important; color: var(--success) !important; }
.kc-option.wrong { border-color: var(--danger) !important; background: var(--danger-bg) !important; color: var(--danger) !important; }
.kc-option:disabled { cursor: default; opacity: 0.7; }
.kc-explanation { display: flex; gap: 0.5rem; align-items: flex-start; padding: 0.75rem; margin-top: 0.75rem; background: var(--warning-bg); border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--text-secondary); }

/* Star Rating (CSS-only) */
.star-rating { display: flex; flex-direction: row-reverse; justify-content: flex-end; gap: 0.1rem; }
.star-rating input { display: none; }
.star-rating label { font-size: 1.5rem; color: var(--text-muted); cursor: pointer; transition: color 0.15s; }
.star-rating input:checked ~ label,
.star-rating label:hover,
.star-rating label:hover ~ label { color: var(--warning); }

/* Onboarding Interest Card */
.onboarding-interest { transition: all 0.2s; }
.onboarding-interest:hover { border-color: rgba(99,102,241,0.3); }

/* ========== Exam & Quiz ========== */
.exam-option { display:flex; align-items:center; gap:0.6rem; padding:0.6rem 0.85rem; border-radius:var(--radius-sm); cursor:pointer; transition:background 0.15s; font-size:0.9rem; }
.exam-option:hover { background:var(--bg-tertiary); }
.exam-option input[type="radio"] { accent-color:var(--accent); width:16px; height:16px; flex-shrink:0; }
.exam-question { transition:border-color 0.15s; }
.exam-question:focus-within { border-color:var(--accent); }

.quiz-section .card { transition:border-color 0.15s; }

/* Success/warning backgrounds */
:root { --success-bg: rgba(52,211,153,0.06); --warning-bg: rgba(251,191,36,0.06); --danger-bg: rgba(248,113,113,0.06); }

/* ========== Glossary ========== */
.glossary-term { transition:border-color 0.15s; }
.glossary-term:hover { border-color:var(--accent-soft); }

/* ========== Quiz Modal ========== */
.quiz-modal-overlay {
    position:fixed; inset:0; z-index:1000;
    background:rgba(0,0,0,0.75); backdrop-filter:blur(4px);
    display:flex; align-items:center; justify-content:center;
    padding:1rem;
}
.quiz-modal {
    background:var(--bg-secondary); border:1px solid var(--border-color);
    border-radius:var(--radius-xl); width:100%; max-width:640px;
    max-height:calc(100vh - 2rem);
    box-shadow:0 20px 60px rgba(0,0,0,0.5);
    overflow-y:auto; overflow-x:hidden;
}
.quiz-modal-header {
    display:flex; justify-content:space-between; align-items:flex-start;
    padding:1.25rem 1.5rem; border-bottom:1px solid var(--border-color);
    position:sticky; top:0; background:var(--bg-secondary); z-index:2;
}
.quiz-modal-questions {
    padding:1.25rem 1.5rem;
    display:flex; flex-direction:column; gap:1rem;
}
.quiz-modal-footer {
    display:flex; justify-content:space-between; align-items:center;
    padding:1rem 1.5rem; border-top:1px solid var(--border-color);
    position:sticky; bottom:0; background:var(--bg-secondary); z-index:2;
}
.quiz-modal-body {
    display:contents;
}

/* Quiz question cards */
.quiz-question-card {
    background:var(--bg-tertiary); border:1px solid var(--border-light);
    border-radius:var(--radius-md); padding:1rem 1.25rem;
}
.quiz-q-num {
    display:flex; align-items:center; justify-content:center;
    width:24px; height:24px; border-radius:50%;
    background:var(--accent); color:white;
    font-size:0.7rem; font-weight:700; flex-shrink:0;
}
.quiz-options { display:flex; flex-direction:column; gap:0.4rem; padding-left:2rem; }
.quiz-option-label {
    display:flex; align-items:center; gap:0.6rem;
    padding:0.5rem 0.75rem; border-radius:var(--radius-sm);
    cursor:pointer; transition:all 0.15s; font-size:0.88rem;
    border:1px solid transparent;
}
.quiz-option-label:hover { background:rgba(99,102,241,0.06); border-color:rgba(99,102,241,0.15); }
.quiz-option-label input[type="radio"] { accent-color:var(--accent); width:16px; height:16px; flex-shrink:0; }
.quiz-option-label:has(input:checked) { background:rgba(99,102,241,0.1); border-color:rgba(99,102,241,0.3); }
.quiz-option-text { line-height:1.4; }