/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #F8F8FC;
    --bg-sidebar: #FFFFFF;
    --bg-card: #FFFFFF;
    --bg-hover: #F0F0F8;
    --bg-active: #E8E8F4;
    --text-primary: #333340;
    --text-secondary: #666680;
    --text-muted: #999AAA;
    --accent: #5B4FD0;
    --accent-hover: #7468E8;
    --accent-dim: rgba(91, 79, 208, 0.1);
    --border: #E0E0EC;
    --success: #22C55E;
    --danger: #EF4444;
    --radius: 10px;
    --sidebar-width: 280px;
    --transition: 0.2s ease;
}

[data-theme="dark"] {
    --bg-primary: #0D1025;
    --bg-sidebar: #0A0D1F;
    --bg-card: #151833;
    --bg-hover: #1C2044;
    --bg-active: #252955;
    --text-primary: #E8E0F0;
    --text-secondary: #9B93A8;
    --text-muted: #6B6580;
    --accent: #7C6FE0;
    --accent-hover: #9488F0;
    --accent-dim: rgba(124, 111, 224, 0.15);
    --border: #1E2140;
}

/* Theme toggle button */
.theme-toggle {
    position: fixed;
    top: 16px;
    right: 20px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: all var(--transition);
    z-index: 1000;
}
.theme-toggle:hover {
    background: var(--bg-hover);
    transform: scale(1.1);
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition);
}

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

/* ===== Login Page ===== */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.login-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 48px 40px;
    text-align: center;
    max-width: 420px;
    width: 100%;
}

.login-card h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.login-card .subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 32px;
}

.login-card .tg-widget {
    display: flex;
    justify-content: center;
    margin-top: 8px;
}

.flash-message {
    background: rgba(248, 113, 113, 0.15);
    border: 1px solid var(--danger);
    color: var(--danger);
    padding: 10px 16px;
    border-radius: var(--radius);
    margin-bottom: 20px;
    font-size: 0.9rem;
}

/* ===== No Access Page ===== */
.no-access-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 20px;
}

.no-access-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 48px 40px;
    text-align: center;
    max-width: 480px;
    width: 100%;
}

.no-access-card .icon {
    font-size: 3rem;
    margin-bottom: 16px;
}

.no-access-card h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.no-access-card p {
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.7;
}

.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    color: #fff;
}

.btn-primary:hover {
    background: var(--accent-hover);
    color: #fff;
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
}

.btn-ghost:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

/* ===== Layout: Sidebar + Main ===== */
.app-layout {
    display: flex;
    min-height: 100vh;
}

/* ===== Sidebar ===== */
.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
    overflow-y: auto;
    transition: transform 0.3s ease;
}

.sidebar-header {
    padding: 24px 20px 16px;
    border-bottom: 1px solid var(--border);
}

.sidebar-header .logo {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 10px;
}

.sidebar-header .logo-icon {
    width: 32px;
    height: 32px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
}

.sidebar-nav {
    flex: 1;
    padding: 12px 0;
    overflow-y: auto;
}

.module-group {
    margin-bottom: 4px;
}

.module-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    user-select: none;
    transition: color var(--transition);
}

.module-header:hover {
    color: var(--text-secondary);
}

.module-header .chevron {
    margin-left: auto;
    font-size: 0.7rem;
    transition: transform 0.2s;
}

.module-header.open .chevron {
    transform: rotate(90deg);
}

.module-lessons {
    display: none;
}

.module-lessons.open {
    display: block;
}

.lesson-link {
    display: block;
    padding: 8px 20px 8px 36px;
    font-size: 0.88rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition);
    border-left: 2px solid transparent;
}

.lesson-link:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.lesson-link.active {
    color: var(--accent);
    background: var(--accent-dim);
    border-left-color: var(--accent);
}

.sidebar-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--border);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-avatar {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: var(--bg-hover);
    object-fit: cover;
}

.user-avatar-placeholder {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: var(--accent-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 600;
}

.user-name {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
}

.user-logout {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.user-logout:hover {
    color: var(--danger);
}

/* ===== Main Content ===== */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 40px 48px;
    max-width: 900px;
}

/* ===== Dashboard ===== */
.dashboard-header {
    margin-bottom: 40px;
}

.dashboard-header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.dashboard-header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.modules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.module-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    transition: all var(--transition);
    text-decoration: none;
    color: inherit;
    display: block;
}

.module-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
    color: inherit;
}

.module-card .card-icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.module-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.module-card .card-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ===== Lesson Content ===== */
.lesson-header {
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border);
}

.lesson-breadcrumb {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.lesson-header h1 {
    font-size: 1.6rem;
    font-weight: 700;
}

.lesson-body h1 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 28px 0 12px;
}

.lesson-body h2 {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 24px 0 10px;
    color: var(--text-primary);
}

.lesson-body h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 20px 0 8px;
}

.lesson-body p {
    margin-bottom: 14px;
    color: var(--text-primary);
    line-height: 1.75;
}

.lesson-body ul, .lesson-body ol {
    margin: 0 0 14px 24px;
}

.lesson-body li {
    margin-bottom: 6px;
    line-height: 1.7;
}

.lesson-body img {
    max-width: 100%;
    border-radius: var(--radius);
    margin: 16px 0;
}

.lesson-body code {
    background: var(--bg-hover);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.88em;
}

.lesson-body pre {
    background: var(--bg-sidebar);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px 20px;
    overflow-x: auto;
    margin: 16px 0;
}

.lesson-body pre code {
    background: none;
    padding: 0;
}

.lesson-body blockquote {
    border-left: 3px solid var(--accent);
    padding: 12px 20px;
    margin: 16px 0;
    background: var(--accent-dim);
    border-radius: 0 var(--radius) var(--radius) 0;
    color: var(--text-secondary);
}

/* Video wrapper */
.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    margin: 20px 0;
    border-radius: var(--radius);
    background: var(--bg-sidebar);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
    border-radius: var(--radius);
}

/* Lesson navigation */
.lesson-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    gap: 16px;
}

.lesson-nav a {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.88rem;
    transition: all var(--transition);
}

.lesson-nav a:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}

.lesson-nav .spacer {
    flex: 1;
}

/* ===== Mobile ===== */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: var(--bg-sidebar);
    border-bottom: 1px solid var(--border);
    z-index: 200;
    padding: 0 16px;
    align-items: center;
    gap: 12px;
}

.mobile-header .burger {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.4rem;
    cursor: pointer;
    padding: 4px;
}

.mobile-header .mobile-title {
    font-size: 1rem;
    font-weight: 600;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 99;
}

@media (max-width: 768px) {
    .mobile-header {
        display: flex;
    }

    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .sidebar-overlay.open {
        display: block;
    }

    .main-content {
        margin-left: 0;
        padding: 72px 20px 40px;
    }

    .login-card {
        padding: 32px 24px;
    }

    .modules-grid {
        grid-template-columns: 1fr;
    }

    .lesson-nav {
        flex-direction: column;
    }

    .lesson-nav a {
        width: 100%;
        justify-content: center;
    }
}

hr { display: none; }


/* Complete button */
.complete-form { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border); }
.complete-btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 24px; border-radius: var(--radius);
    border: 2px solid var(--accent); background: transparent;
    color: var(--accent); font-size: 15px; font-weight: 600;
    cursor: pointer; transition: all var(--transition);
}
.complete-btn:hover { background: var(--accent-dim); }
.complete-btn.completed { background: var(--accent); color: #fff; border-color: var(--accent); }
.complete-btn.completed:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

/* Sidebar checkmarks */
.lesson-check { margin-right: 6px; font-size: 14px; }
.lesson-check.done { color: var(--success); }
.lesson-check.pending { color: var(--text-muted); opacity: 0.4; }

/* Progress bar */
.progress-section { margin-bottom: 30px; }
.progress-info { display: flex; justify-content: space-between; margin-bottom: 8px; font-size: 14px; color: var(--text-secondary); }
.progress-pct { font-weight: 700; color: var(--accent); }
.progress-bar { height: 8px; background: var(--border); border-radius: 4px; overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-hover)); border-radius: 4px; transition: width 0.5s ease; min-width: 0; }

/* Custom checkbox icon */
.checkbox-icon {
    display: inline-block;
    width: 18px; height: 18px;
    border: 2px solid var(--accent);
    border-radius: 4px;
    vertical-align: middle;
    position: relative;
    flex-shrink: 0;
}
.checkbox-icon.checked {
    background: var(--accent);
    border-color: var(--accent);
}
.checkbox-icon.checked::after {
    content: '✓';
    position: absolute;
    top: -2px; left: 2px;
    color: #fff;
    font-size: 14px;
    font-weight: bold;
}
.complete-btn.completed .checkbox-icon {
    border-color: #fff;
    background: rgba(255,255,255,0.3);
}
.complete-btn.completed .checkbox-icon::after {
    color: #fff;
}

/* Expandable module cards */
.module-card { cursor: pointer; text-decoration: none; }
.card-header { display: flex; flex-direction: column; }
.card-chevron { 
    color: var(--text-muted); font-size: 18px; 
    transition: transform var(--transition);
    margin-top: 8px;
}
.module-card.expanded .card-chevron { transform: rotate(180deg); }
.card-lessons {
    max-height: 0; overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0;
}
.module-card.expanded .card-lessons {
    max-height: 500px;
    padding-top: 12px;
    margin-top: 12px;
    border-top: 1px solid var(--border);
}
.card-lesson-link {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 4px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    border-radius: 6px;
    transition: background var(--transition);
}
.card-lesson-link:hover { background: var(--bg-hover); }

/* Module lessons list page */
.module-lessons-list { display: flex; flex-direction: column; gap: 8px; }
.module-lesson-item {
    display: flex; align-items: center; gap: 14px;
    padding: 16px 18px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text-primary);
    transition: all var(--transition);
}
.module-lesson-item:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}
.module-lesson-info { flex: 1; }
.module-lesson-title { font-size: 16px; font-weight: 500; }
.module-lesson-arrow { color: var(--text-muted); font-size: 18px; }
.module-lesson-item:hover .module-lesson-arrow { color: var(--accent); }