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

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #272727;
    --bg-hover: #333;
    --text-primary: #f1f1f1;
    --text-secondary: #aaa;
    --text-muted: #717171;
    --accent: #3ea6ff;
    --accent-hover: #65b8ff;
    --border: #333;
    --success: #2ecc71;
    --radius: 8px;
    --radius-lg: 12px;
    --topnav-h: 56px;
}

html { font-size: 15px; }
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

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

/* ── Buttons ─────────────────────────────────────────────── */
.btn {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 8px 16px; border-radius: var(--radius);
    font-size: .875rem; font-weight: 500;
    cursor: pointer; border: none; transition: all .15s;
}
.btn--sm { padding: 5px 12px; font-size: .8rem; }
.btn--primary { background: var(--accent); color: #000; }
.btn--primary:hover { background: var(--accent-hover); }
.btn--ghost { background: transparent; color: var(--text-secondary); border: 1px solid var(--border); }
.btn--ghost:hover { background: var(--bg-tertiary); color: var(--text-primary); }

/* ── Top Nav ─────────────────────────────────────────────── */
.topnav {
    position: fixed; top: 0; left: 0; right: 0;
    height: var(--topnav-h);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 20px;
    z-index: 1000;
}
.topnav__brand {
    display: flex; align-items: center; gap: 10px;
    color: var(--text-primary); font-size: 1.2rem; font-weight: 700;
    flex-shrink: 0;
}
.topnav__brand svg { color: var(--accent); }
.topnav__right { display: flex; align-items: center; gap: 12px; }
.topnav__user { color: var(--text-secondary); font-size: .875rem; }

/* Hamburger — hidden on desktop */
.topnav__hamburger {
    display: none;
    background: none; border: none; cursor: pointer;
    flex-direction: column; gap: 5px; padding: 4px;
    z-index: 1001;
}
.topnav__hamburger span {
    display: block; width: 22px; height: 2px;
    background: var(--text-primary); border-radius: 2px;
    transition: all .25s;
}
.topnav__hamburger--active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.topnav__hamburger--active span:nth-child(2) { opacity: 0; }
.topnav__hamburger--active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.main-content { margin-top: var(--topnav-h); }

/* ── Login Page ──────────────────────────────────────────── */
.login-page {
    display: flex; align-items: center; justify-content: center;
    min-height: calc(100vh - var(--topnav-h));
    padding: 20px;
}
.login-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    width: 100%; max-width: 400px;
}
.login-card h1 { font-size: 1.5rem; margin-bottom: 8px; }
.login-card p { color: var(--text-secondary); margin-bottom: 24px; font-size: .9rem; }
.form-group { margin-bottom: 16px; }
.form-group label {
    display: block; font-size: .85rem; font-weight: 500;
    margin-bottom: 6px; color: var(--text-secondary);
}
.form-group input {
    width: 100%; padding: 10px 14px;
    background: var(--bg-tertiary); border: 1px solid var(--border);
    border-radius: var(--radius); color: var(--text-primary);
    font-size: .95rem;
}
.form-group input:focus { outline: none; border-color: var(--accent); }
.login-card .btn { width: 100%; justify-content: center; margin-top: 8px; padding: 12px; }
.login-error {
    background: #3a1c1c; border: 1px solid #7a2d2d; color: #ff7b7b;
    padding: 10px 14px; border-radius: var(--radius);
    margin-bottom: 16px; font-size: .85rem;
}

/* ── Course Grid (Home Page) ─────────────────────────────── */
.page-header { padding: 32px 24px 16px; }
.page-header h1 { font-size: 1.6rem; font-weight: 700; }
.page-header p { color: var(--text-secondary); margin-top: 4px; }
.page-header__row {
    display: flex; align-items: flex-start; justify-content: space-between;
    gap: 16px; flex-wrap: wrap;
}

/* ── Sort Controls ─────────────────────────────────────── */
.sort-control { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }
.sort-control__label { font-size: .8rem; color: var(--text-muted); white-space: nowrap; }
.sort-control__select {
    appearance: none;
    -webkit-appearance: none;
    background: var(--bg-tertiary) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23aaa' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E") no-repeat right 8px center;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: .8rem;
    padding: 6px 28px 6px 10px;
    cursor: pointer;
    transition: border-color .15s;
}
.sort-control__select:hover { border-color: var(--accent); color: var(--text-primary); }
.sort-control__select:focus { outline: none; border-color: var(--accent); }
.sort-control__select--sm { padding: 3px 24px 3px 8px; font-size: .75rem; }

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    padding: 0 24px 40px;
}
.course-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all .2s;
    display: flex; flex-direction: column;
}
.course-card:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,0,0,.3);
}
.course-card__cover {
    width: 100%; height: 170px;
    overflow: hidden; background: var(--bg-tertiary);
}
.course-card__cover img { width: 100%; height: 100%; object-fit: cover; display: block; }
.course-card__cover--placeholder {
    display: flex; align-items: center; justify-content: center;
}
.course-card__cover--placeholder svg { color: var(--text-muted); }
.course-card__body {
    padding: 16px 20px 20px;
    flex: 1; display: flex; flex-direction: column;
}
.course-card__body h2 { font-size: 1.1rem; font-weight: 600; margin-bottom: 8px; }
.course-card__meta { color: var(--text-muted); font-size: .8rem; margin-top: auto; }

/* Progress & Access */
.course-card-wrapper { position: relative; }
.course-card-wrapper--hidden { opacity: 0.45; }
.course-card-wrapper--hidden:hover { opacity: 0.75; }
.course-card__progress {
    display: flex; align-items: center; gap: 6px;
    font-size: .75rem; color: var(--accent); margin-top: 8px;
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.course-card__progress svg { flex-shrink: 0; }
.course-card__actions {
    position: absolute; top: 8px; right: 8px;
    display: flex; gap: 4px;
    opacity: 0; transition: opacity .2s; z-index: 2;
}
.course-card-wrapper:hover .course-card__actions { opacity: 1; }
.course-card-wrapper--hidden .course-card__actions { opacity: 1; }
.course-card__action-btn {
    background: var(--bg-secondary); border: 1px solid var(--border);
    border-radius: 6px; padding: 6px 8px; cursor: pointer;
    color: var(--text-muted); transition: color .2s, border-color .2s;
}
.course-card__action-btn:hover { color: var(--accent); border-color: var(--accent); }

/* ── Course Detail (Player Page) ─────────────────────────── */
.course-layout {
    display: grid;
    grid-template-columns: 1fr 360px;
    min-height: calc(100vh - var(--topnav-h));
}

.player-area {
    padding: 24px;
    overflow-y: auto;
    display: flex; flex-direction: column; align-items: center;
}
.player-wrapper {
    background: #000;
    border-radius: var(--radius-lg);
    overflow: hidden;
    width: 100%; max-width: 1100px;
    position: relative;
}
.transcode-overlay {
    position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    z-index: 10;
    background: rgba(0,0,0,.92);
    display: flex; align-items: center; justify-content: center;
    text-align: center; padding: 24px;
    min-height: 480px;
}
.transcode-overlay__inner { max-width: 400px; }
.transcode-overlay h3 { font-size: 1.1rem; margin-bottom: 8px; }
.video-js { width: 100%; min-height: 480px; }
.player-info { padding: 16px 0; width: 100%; max-width: 1100px; }
.player-info h1 { font-size: 1.25rem; font-weight: 600; }
.player-info__meta { color: var(--text-muted); font-size: .85rem; margin-top: 4px; }

/* Audio player */
.audio-player-wrapper {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    width: 100%; max-width: 600px;
    display: flex; flex-direction: column; align-items: center;
    gap: 24px;
}
.audio-player-art {
    width: 120px; height: 120px;
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-primary));
    border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
}
.audio-player-art svg { color: var(--accent); }
.audio-player-wrapper .video-js {
    width: 100%; min-height: auto; height: 50px;
    background: transparent !important;
}
.audio-player-wrapper .vjs-poster { display: none; }

/* Download prompt for non-video/audio */
.download-prompt {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 60px 40px;
    text-align: center;
    width: 100%; max-width: 600px;
}

/* Image viewer */
.image-viewer {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    width: 100%; max-width: 1100px;
    display: flex; align-items: center; justify-content: center;
    min-height: 300px;
}
.image-viewer img { max-width: 100%; max-height: 80vh; object-fit: contain; display: block; }
.download-prompt svg { color: var(--text-muted); margin-bottom: 16px; }
.download-prompt h2 { font-size: 1.2rem; margin-bottom: 8px; }
.download-prompt p { color: var(--text-secondary); margin-bottom: 20px; }

/* ── Sidebar ──────────────────────────────────────────────── */
.sidebar {
    background: var(--bg-secondary);
    border-left: 1px solid var(--border);
    overflow-y: auto;
    height: calc(100vh - var(--topnav-h));
    position: sticky;
    top: var(--topnav-h);
}
.sidebar__header {
    padding: 16px 16px 12px;
    font-weight: 600; font-size: .95rem;
    border-bottom: 1px solid var(--border);
    position: sticky; top: 0;
    background: var(--bg-secondary);
    z-index: 10;
}
.sidebar__title-row {
    display: flex; align-items: center; justify-content: space-between;
    gap: 8px; margin-top: 4px;
}
.sidebar__title-row > span {
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0;
}

/* ── Tree View (collapsible sidebar) ─────────────────────── */
.sidebar-tree {
    padding: 6px 0;
}

/* Folder node */
.tree-node {
    content-visibility: auto;
    contain-intrinsic-size: 0 36px;
}
.tree-folder {
    display: flex; align-items: center; gap: 6px;
    padding: 7px 12px 7px 12px;
    font-size: .85rem; font-weight: 600;
    color: var(--text-secondary);
    cursor: default;
    user-select: none;
}
.tree-toggle {
    background: none; border: none; cursor: pointer;
    display: flex; align-items: center; justify-content: center;
    width: 20px; height: 20px; flex-shrink: 0;
    border-radius: 4px; padding: 0;
    color: var(--text-muted);
    transition: background .1s;
}
.tree-toggle:hover { background: var(--bg-tertiary); color: var(--text-primary); }
.tree-chevron { transition: transform .2s; }
.tree-node:not(.tree-node--collapsed) > .tree-folder .tree-chevron {
    transform: rotate(90deg);
}
.tree-folder-icon { color: var(--accent); flex-shrink: 0; opacity: .7; }
.tree-folder-name { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* Children container — hidden when collapsed */
.tree-children {
    overflow: hidden;
    transition: max-height .2s ease;
}
.tree-node--collapsed > .tree-children {
    display: none;
}

/* File items inside tree */
.file-item {
    display: flex; align-items: center; gap: 10px;
    padding: 7px 12px;
    color: var(--text-primary);
    transition: background .1s;
    cursor: pointer;
    font-size: .85rem;
}
.file-item:hover { background: var(--bg-tertiary); color: var(--text-primary); }
.file-item--active {
    background: var(--bg-tertiary);
    border-left: 3px solid var(--accent);
}
.file-item__icon {
    flex-shrink: 0;
    width: 28px; height: 28px;
    background: var(--bg-primary);
    border-radius: 6px;
    display: flex; align-items: center; justify-content: center;
}
.file-item__icon svg { width: 14px; height: 14px; }
.file-item__icon--video svg { color: var(--accent); }
.file-item__icon--audio svg { color: #f59e0b; }
.file-item__icon--image svg { color: #e879f9; }
.file-item__icon--file svg { color: var(--text-muted); }
.file-item__info { flex: 1; min-width: 0; }
.file-item__title {
    white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.file-item__size { font-size: .7rem; color: var(--text-muted); }

/* ── No Content State ────────────────────────────────────── */
.empty-state {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    min-height: 400px; text-align: center; padding: 40px;
}
.empty-state svg { color: var(--text-muted); margin-bottom: 16px; }
.empty-state h2 { font-size: 1.2rem; margin-bottom: 8px; }
.empty-state p { color: var(--text-secondary); max-width: 400px; }
.empty-state code {
    display: block; background: var(--bg-tertiary); padding: 12px 20px;
    border-radius: var(--radius); margin-top: 16px;
    font-size: .85rem; color: var(--accent);
}

/* ── Video.js – Red progress bar ──────────────────────────── */
.video-js .vjs-play-progress {
    background-color: #e53e3e !important;
}
.video-js .vjs-play-progress:before {
    color: #e53e3e !important;
    font-size: 0.85em;
    top: 50% !important;
    transform: translateY(-50%);
    position: absolute;
    right: -0.5em;
    line-height: 1;
}
.video-js .vjs-progress-control { align-items: center; }
.video-js .vjs-progress-holder {
    background: rgba(255,255,255,.15) !important;
    height: 0.4em !important;
}
.video-js .vjs-play-progress,
.video-js .vjs-load-progress { height: 100% !important; }
.video-js .vjs-mouse-display { height: 100% !important; }
.video-js .vjs-slider:focus .vjs-play-progress {
    background-color: #e53e3e !important;
}
.video-js .vjs-load-progress { background: rgba(255,255,255,.1) !important; }
.video-js .vjs-load-progress div { background: rgba(255,255,255,.15) !important; }

/* ── Modal ───────────────────────────────────────────────── */
.modal-overlay {
    position: fixed; inset: 0;
    background: rgba(0,0,0,.7);
    display: flex; align-items: center; justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(4px);
}
.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    width: 90%; max-width: 560px;
    max-height: 80vh;
    display: flex; flex-direction: column;
    box-shadow: 0 20px 60px rgba(0,0,0,.5);
}
.modal__header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 20px 24px 16px;
    border-bottom: 1px solid var(--border);
}
.modal__header h2 { font-size: 1.1rem; font-weight: 600; }
.modal__close {
    background: none; border: none; color: var(--text-muted);
    font-size: 1.5rem; cursor: pointer; padding: 0 4px; line-height: 1;
}
.modal__close:hover { color: var(--text-primary); }
.modal__body { padding: 20px 24px; overflow-y: auto; flex: 1; }

.scan-spinner {
    display: flex; flex-direction: column; align-items: center; gap: 12px;
    padding: 20px 0; color: var(--text-secondary);
}
.scan-spinner svg { animation: spin 1s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.scan-summary { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.scan-stat {
    padding: 4px 12px; border-radius: 20px;
    font-size: .8rem; font-weight: 500;
    background: var(--bg-tertiary); color: var(--text-secondary);
}
.scan-stat--added { background: #1a3a2a; color: #4ade80; }
.scan-stat--removed { background: #3a1c1c; color: #ff7b7b; }
.scan-stat--updated { background: #2a2a1a; color: #fbbf24; }
.scan-empty { text-align: center; padding: 20px; color: var(--text-muted); font-size: .9rem; }

.scan-group-label {
    font-size: .75rem; font-weight: 600; text-transform: uppercase;
    letter-spacing: .05em; color: var(--text-muted);
    padding: 12px 0 6px; border-bottom: 1px solid var(--border); margin-bottom: 4px;
}
.scan-item {
    padding: 8px 12px; border-radius: var(--radius);
    font-size: .85rem; margin-bottom: 4px;
}
.scan-item strong { font-weight: 500; }
.scan-detail { color: var(--text-muted); font-size: .8rem; }
.scan-item--added { background: rgba(74,222,128,.06); }
.scan-item--removed { background: rgba(255,123,123,.06); color: #ff7b7b; }
.scan-item--updated { background: rgba(251,191,36,.06); color: #fbbf24; }

/* ── Library Management ───────────────────────────────────── */
.lib-page { max-width: 800px; margin: 0 auto; padding: 0 24px 40px; }
.lib-add-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px; margin-bottom: 24px;
}
.lib-add-card h3 { font-size: 1rem; font-weight: 600; margin-bottom: 16px; }
.lib-add-form { display: flex; flex-wrap: wrap; gap: 12px; align-items: flex-end; }
.lib-add-form .form-group { flex: 1; min-width: 200px; margin-bottom: 0; }
.lib-error {
    width: 100%;
    background: #3a1c1c; border: 1px solid #7a2d2d; color: #ff7b7b;
    padding: 8px 14px; border-radius: var(--radius);
    font-size: .85rem; margin-top: 4px;
}
.lib-list { display: flex; flex-direction: column; gap: 12px; }
.lib-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.lib-card__info { flex: 1; min-width: 0; }
.lib-card__name { font-weight: 600; font-size: .95rem; display: flex; align-items: center; gap: 8px; }
.lib-card__path { margin-top: 4px; display: flex; align-items: center; gap: 8px; }
.lib-card__path code {
    font-size: .8rem; color: var(--text-muted);
    background: var(--bg-tertiary); padding: 2px 8px;
    border-radius: 4px; word-break: break-all;
}
.lib-card__meta { margin-top: 6px; font-size: .8rem; color: var(--text-muted); }
.lib-card__actions { display: flex; gap: 8px; flex-shrink: 0; }
.lib-badge {
    font-size: .7rem; font-weight: 600; text-transform: uppercase;
    padding: 2px 8px; border-radius: 10px; letter-spacing: .03em;
}
.lib-badge--active { background: #1a3a2a; color: #4ade80; }
.lib-badge--inactive { background: var(--bg-tertiary); color: var(--text-muted); }
.lib-badge--error { background: #3a1c1c; color: #ff7b7b; }
.lib-btn--danger { color: #ff7b7b !important; border-color: #7a2d2d !important; }
.lib-btn--danger:hover { background: #3a1c1c !important; }
.lib-empty { text-align: center; padding: 40px; color: var(--text-muted); }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 900px) {
    .course-layout { grid-template-columns: 1fr; }
    .sidebar {
        position: static; height: auto;
        border-left: none; border-top: 1px solid var(--border);
        max-height: 50vh; overflow-y: auto;
    }
    .video-js { min-height: 240px; }
    .course-grid { grid-template-columns: 1fr; }
    .player-area { padding: 12px; }
}

@media (max-width: 640px) {
    /* Show hamburger, hide nav by default */
    .topnav__hamburger {
        display: flex;
    }
    .topnav__right {
        display: none;
        position: absolute;
        top: var(--topnav-h);
        left: 0; right: 0;
        background: var(--bg-secondary);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 12px 20px;
        gap: 8px;
        box-shadow: 0 8px 24px rgba(0,0,0,.4);
    }
    .topnav__right--open {
        display: flex;
    }
    .topnav__right .btn {
        width: 100%; justify-content: center;
    }
    .topnav__right form { width: 100%; }
    .topnav__right form .btn { width: 100%; justify-content: center; }

    .page-header { padding: 20px 16px 12px; }
    .page-header h1 { font-size: 1.3rem; }
    .course-grid { padding: 0 16px 24px; gap: 12px; }

    .audio-player-wrapper { padding: 24px 16px; }
    .audio-player-art { width: 80px; height: 80px; }
    .audio-player-art svg { width: 40px; height: 40px; }

    .lib-page { padding: 0 12px 24px; }
    .lib-card { flex-direction: column; align-items: flex-start; }
    .lib-card__actions { width: 100%; }
}