:root {
    --bg: #0e0e10;
    --panel: #17171a;
    --panel-2: #1f1f23;
    --line: #2c2c31;
    --text: #e9e7e4;
    --muted: #8d8a86;
    --accent: #d42a2a;
    --accent-hi: #ff4a3d;
    --ok: #4caf6a;
    --paper: #f6f4ef;
    --radius: 8px;
    font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
    color-scheme: dark;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-size: 14px;
}

h1, h2, h3 { margin: 0; font-weight: 700; }
button, input, select { font: inherit; color: inherit; }

.muted { color: var(--muted); }
.small { font-size: 12px; }

.app {
    display: grid;
    grid-template-columns: 280px 1fr;
    height: 100vh;
}

/* ---------- Sidebar ---------- */
.sidebar {
    background: var(--panel);
    border-right: 1px solid var(--line);
    padding: 18px 16px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { font-size: 17px; letter-spacing: 0.06em; text-transform: uppercase; }
.brand-mark { color: var(--accent); font-size: 18px; }

.sidebar h2 {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--muted);
    margin-bottom: 6px;
}

.add-song span {
    display: block;
    text-align: center;
    padding: 10px;
    border: 1px dashed var(--accent);
    border-radius: var(--radius);
    color: var(--accent-hi);
    cursor: pointer;
    font-weight: 600;
}
.add-song span:hover { background: rgba(212, 42, 42, 0.08); }
.hint { margin: -6px 0 0; font-size: 12px; color: var(--muted); }

.song-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.song-list button {
    width: 100%;
    text-align: left;
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius);
    padding: 8px 10px;
    cursor: pointer;
}
.song-list button:hover { background: var(--panel-2); }
.song-list button[aria-current="true"] { background: var(--panel-2); border-color: var(--accent); }
.song-list .title { display: block; font-weight: 600; }
.song-list .meta { display: block; font-size: 12px; color: var(--muted); margin-top: 2px; }
.empty { font-size: 12px; color: var(--muted); margin: 0; }

.tags { display: flex; flex-wrap: wrap; gap: 6px; }

.filters { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.filters select { width: 100%; padding: 6px 8px; font-size: 13px; }

.count { color: var(--muted); font-weight: 400; letter-spacing: 0; }

.drill-group { margin-bottom: 6px; }
.drill-group summary {
    cursor: pointer;
    padding: 6px 4px;
    font-weight: 700;
    font-size: 13px;
    border-bottom: 1px solid var(--line);
    margin-bottom: 4px;
    user-select: none;
}
.drill-group summary:hover { color: var(--accent-hi); }

.level {
    display: inline-block;
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 1px 6px;
    border-radius: 999px;
    vertical-align: 1px;
    border: 1px solid currentColor;
}
.level-beginner { color: var(--ok); }
.level-intermediate { color: #e0a93b; }
.level-advanced { color: var(--accent-hi); }

.tip {
    margin: 6px 0 0;
    max-width: 70ch;
    font-size: 13px;
    color: var(--text);
    border-left: 3px solid var(--accent);
    padding-left: 10px;
}
.chip {
    font-size: 12px;
    padding: 3px 9px;
    border-radius: 999px;
    border: 1px solid var(--line);
    background: var(--panel-2);
    cursor: pointer;
}
.chip[aria-pressed="true"] { border-color: var(--accent); color: var(--accent-hi); }
.chip .x { margin-left: 4px; color: var(--muted); }
.tags input {
    width: 130px;
    background: transparent;
    border: 1px dashed var(--line);
    border-radius: 999px;
    padding: 3px 9px;
    font-size: 12px;
}

.overall { margin-top: auto; border-top: 1px solid var(--line); padding-top: 12px; font-size: 12px; color: var(--muted); }
.overall strong { color: var(--text); }

/* ---------- Main ---------- */
.main {
    display: flex;
    flex-direction: column;
    min-width: 0;
    height: 100vh;
}

.song-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    padding: 16px 20px 10px;
}
.song-header h2 { font-size: 22px; }
.song-header p { margin: 2px 0 0; }
.song-header-actions { display: flex; gap: 8px; align-items: center; }

button, select {
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 7px 12px;
    cursor: pointer;
}
button:hover:not(:disabled) { border-color: var(--muted); }
button:disabled, select:disabled { opacity: 0.45; cursor: not-allowed; }
button.primary { background: var(--accent); border-color: var(--accent); font-weight: 700; min-width: 96px; }
button.primary:hover:not(:disabled) { background: var(--accent-hi); border-color: var(--accent-hi); }
button.ghost { background: transparent; }
button.danger { color: #ff7b72; }
button.active { border-color: var(--accent); color: var(--accent-hi); }

:focus-visible { outline: 2px solid var(--accent-hi); outline-offset: 2px; }

.transport {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    padding: 10px 20px;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: var(--panel);
}
.speed { display: flex; align-items: center; gap: 8px; }
.speed input[type="range"] { width: 160px; accent-color: var(--accent); }
.speed output { font-variant-numeric: tabular-nums; min-width: 42px; font-weight: 700; }
.toggle { display: flex; align-items: center; gap: 5px; cursor: pointer; user-select: none; }
.toggle input { accent-color: var(--accent); }

.practice-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    padding: 12px 20px;
}
.panel {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 12px 14px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.panel h3 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.08em; }
.panel p { margin: 0; }

.trainer-fields { display: flex; flex-wrap: wrap; gap: 10px; }
.trainer-fields label, .goal label { display: flex; align-items: center; gap: 4px; font-size: 13px; }
input[type="number"] {
    width: 58px;
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 4px 6px;
}
.trainer-actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
#tr-status { font-variant-numeric: tabular-nums; }

.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin: 0; }
.stats div { background: var(--panel-2); border-radius: 6px; padding: 6px 8px; }
.stats dt { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }
.stats dd { margin: 2px 0 0; font-size: 16px; font-weight: 700; font-variant-numeric: tabular-nums; }

.goal { display: flex; align-items: center; gap: 10px; }
.meter { flex: 1; height: 8px; background: var(--panel-2); border-radius: 999px; overflow: hidden; }
.meter span { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--accent), var(--accent-hi)); transition: width 0.3s; }
.meter.reached span { background: var(--ok); }

/* ---------- Score ---------- */
.score-wrap {
    position: relative;
    flex: 1;
    overflow-y: auto;
    margin: 0 20px 20px;
    background: var(--paper);
    border-radius: var(--radius);
    color: #111;
}
.score-hint { margin: 0; padding: 10px 16px 0; font-size: 12px; color: #6b6660; }
.loading {
    position: sticky;
    top: 0;
    z-index: 10;
    background: var(--accent);
    color: #fff;
    text-align: center;
    padding: 6px;
    font-weight: 600;
}

/* alphaTab cursor + selection styling */
.at-cursor-bar { background: rgba(212, 42, 42, 0.08); }
.at-selection div { background: rgba(212, 42, 42, 0.18); }
.at-cursor-beat { background: var(--accent); width: 3px; }
.at-highlight * { fill: var(--accent); stroke: var(--accent); }

/* ---------- YouTube ---------- */
.yt-add { display: flex; gap: 6px; }
.yt-add input {
    flex: 1;
    min-width: 0;
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 7px 10px;
}
.yt-add input:focus { border-color: var(--accent); outline: none; }

.riff-list { margin: 2px 0 4px 14px; padding-left: 8px; border-left: 2px solid var(--line); }
.riff-list button { padding: 5px 8px; }
.riff-list .title { font-weight: 500; }

.video-area {
    flex: 1;
    overflow-y: auto;
    padding: 0 20px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.video-frame {
    position: relative;
    width: 100%;
    max-width: calc(52vh * 16 / 9);
    aspect-ratio: 16 / 9;
    margin: 0 auto;
    background: #000;
    border-radius: var(--radius);
    overflow: hidden;
}
.video-frame iframe, .video-frame > div { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }

/* The area scrolls; don't let flexbox squash the video or panels to fit. */
.video-area > * { flex-shrink: 0; }

/* Shrink the video when a riff's tab is showing so both fit on screen. */
.video-area.has-tab .video-frame { max-width: calc(34vh * 16 / 9); }

.tab-head-actions, .tab-empty-actions, .tab-form-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.tab-empty p { margin: 0 0 8px; }
.tab-form { display: flex; flex-direction: column; gap: 8px; }
.tab-form textarea {
    width: 100%;
    font: 13px/1.35 ui-monospace, "Cascadia Mono", Consolas, monospace;
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 8px 10px;
    color: var(--text);
    resize: vertical;
    white-space: pre;
    overflow-x: auto;
}
.tab-link-fields { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.tab-link-fields label { display: flex; align-items: center; gap: 6px; font-size: 13px; }
.tab-link-fields select { max-width: 280px; }
#tab-note:empty, #tab-paste-status:empty, #tab-link-status:empty { display: none; }
.tab-view {
    background: var(--paper);
    border-radius: 6px;
    max-height: 46vh;
    overflow-y: auto;
    color: #111;
}

.riff-editor-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; }
kbd {
    font: 11px ui-monospace, monospace;
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: 4px;
    padding: 0 5px;
}

.timeline {
    position: relative;
    height: 30px;
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: 6px;
    cursor: pointer;
    overflow: hidden;
}
.timeline-riff {
    position: absolute;
    top: 3px;
    bottom: 3px;
    min-width: 4px;
    padding: 0;
    border-radius: 4px;
    background: rgba(212, 42, 42, 0.35);
    border: 1px solid var(--accent);
}
.timeline-riff.active { background: var(--accent); }
.timeline-draft {
    position: absolute;
    top: 0;
    bottom: 0;
    background: rgba(233, 231, 228, 0.12);
    border-left: 2px dashed var(--text);
    border-right: 2px dashed var(--text);
    pointer-events: none;
}
.timeline-playhead {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #fff;
    pointer-events: none;
}

.riff-fields, .riff-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.riff-fields label { display: flex; align-items: center; gap: 4px; font-size: 13px; }
.riff-fields input {
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 6px 8px;
}
.riff-name { flex: 1 1 200px; min-width: 0; }
.riff-fields input.time { width: 78px; font-variant-numeric: tabular-nums; }

/* ---------- Share ---------- */
.share-wrap { position: relative; }
#share-btn { border-color: var(--accent); font-weight: 600; }
.share-menu {
    position: absolute;
    /* Share is the first button in its row, so open rightwards to stay on screen. */
    left: 0;
    top: calc(100% + 6px);
    z-index: 50;
    width: min(260px, calc(100vw - 32px));
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.5);
    padding: 6px;
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.share-menu a, .share-menu button {
    display: block;
    width: 100%;
    text-align: left;
    padding: 9px 10px;
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: var(--text);
    text-decoration: none;
    font-size: 14px;
    cursor: pointer;
}
.share-menu a:hover, .share-menu button:hover { background: var(--panel); }
.share-note {
    margin: 4px 4px 2px;
    padding-top: 6px;
    border-top: 1px solid var(--line);
    font-size: 12px;
    color: var(--muted);
}

/* ---------- Overlays ---------- */
.drop-overlay {
    position: fixed;
    inset: 0;
    background: rgba(14, 14, 16, 0.85);
    border: 3px dashed var(--accent);
    display: grid;
    place-items: center;
    font-size: 22px;
    font-weight: 700;
    z-index: 100;
}
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--panel-2);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 10px 16px;
    z-index: 101;
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.5);
    /* Never block the controls underneath (e.g. Save right after adding a video). */
    pointer-events: none;
    max-width: calc(100vw - 32px);
}
.toast.error { border-color: var(--accent); }

[hidden] { display: none !important; }

@media (max-width: 900px) {
    .app { grid-template-columns: 1fr; height: auto; }
    .sidebar { border-right: none; border-bottom: 1px solid var(--line); }
    /* Player first on phones, so a shared drill link opens straight onto the drill. */
    .main { height: auto; order: -1; }
    .practice-row { grid-template-columns: 1fr; padding: 12px 16px; }
    .score-wrap { margin: 0 16px 16px; min-height: 70vh; }
    .video-area { padding: 0 16px 16px; }
    .video-frame { max-width: 100%; }
    .song-header, .transport { padding-left: 16px; padding-right: 16px; }
    .song-header { flex-wrap: wrap; }
    .stats { grid-template-columns: repeat(2, 1fr); }
}