:root {
  --bg: #0f1117;
  --card: #181b24;
  --card-2: #20242f;
  --border: #2b3040;
  --text: #e8eaf0;
  --muted: #9aa0b0;
  --accent: #4a8ce0;
  --accent-2: #3a6db3;
  --radius: 14px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", "Heebo", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.site-header {
  text-align: center;
  padding: 32px 20px 12px;
}
.site-header h1 { margin: 0 0 8px; font-size: 1.9rem; }
.tagline { color: var(--muted); max-width: 640px; margin: 0 auto; }

/* ---- Tutorial video ---- */
.tutorial {
  max-width: 720px;
  margin: 8px auto 0;
  padding: 0 20px;
}
.tutorial > summary {
  cursor: pointer;
  list-style: none;
  text-align: center;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 18px;
  font-weight: 700;
  color: var(--text);
  transition: border-color .15s, background .15s;
}
.tutorial > summary::-webkit-details-marker { display: none; }
.tutorial > summary:hover { border-color: var(--accent); background: var(--card-2); }
.tutorial[open] > summary { border-radius: var(--radius) var(--radius) 0 0; }
.tutorial-body {
  background: var(--card);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 14px;
}
.video-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 10px;
  overflow: hidden;
  background: #000;
}
.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.layout {
  display: grid;
  grid-template-columns: minmax(320px, 1fr) minmax(360px, 1.3fr);
  gap: 20px;
  max-width: 1200px;
  margin: 20px auto;
  padding: 0 20px;
  align-items: start;
}
/* Preview stays visible while scrolling the controls, so design changes are live. */
.preview-pane { position: sticky; top: 16px; align-self: start; }
@media (max-width: 880px) {
  .layout { display: flex; flex-direction: column; }
  .preview-pane { order: -1; position: sticky; top: 0; z-index: 5; }
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 18px;
}
.card h2 { margin: 0 0 14px; font-size: 1.15rem; }

/* ---- Collapsible + draggable cards ---- */
.card-toggle {
  width: 100%; display: flex; justify-content: space-between; align-items: center;
  color: var(--text); font-size: 1.15rem; font-weight: 600; margin: 0 0 14px;
}
.card-toggle .th-left { display: flex; align-items: center; gap: 8px; cursor: pointer; flex: 1; }
.card-toggle .grip { cursor: grab; color: var(--muted); font-size: 1.05rem; line-height: 1; user-select: none; }
.card-toggle .grip:active { cursor: grabbing; }
.card.collapsed .card-toggle { margin-bottom: 0; }
.card-toggle .chev { color: var(--muted); transition: transform 0.15s; font-size: 0.85rem; cursor: pointer; }
.card.collapsed .card-toggle .chev { transform: rotate(-90deg); }
.card.collapsed .card-body { display: none; }
.card.dragging { opacity: 0.5; outline: 2px dashed var(--accent); }
/* Export lives in the preview pane and isn't part of the reorderable list */
.preview-pane .grip { display: none; }
.preview-pane .th-left { cursor: default; }
.card h3 { margin: 0 0 6px; font-size: 1rem; }
.card h3.sub { margin: 18px 0 10px; padding-top: 14px; border-top: 1px solid var(--border); font-size: 0.95rem; color: var(--muted); }

/* ---- Segmented toggle ---- */
.seg-toggle { display: flex; gap: 4px; margin-top: 6px; background: var(--card-2); border: 1px solid var(--border); border-radius: 9px; padding: 4px; }
.seg { flex: 1; border: none; background: transparent; color: var(--muted); padding: 8px 10px; border-radius: 6px; cursor: pointer; font-family: inherit; font-size: 0.9rem; }
.seg.active { background: var(--accent); color: #fff; font-weight: 600; }
.check-row { display: flex; align-items: center; gap: 8px; margin: 8px 0; font-size: 0.9rem; color: var(--text); cursor: pointer; }
.check-row input[type="checkbox"] { width: auto; margin: 0; accent-color: var(--accent); cursor: pointer; }
.import-panel { margin: 8px 0; padding: 10px; background: var(--card-2); border: 1px solid var(--border); border-radius: 9px; }
.import-panel textarea { width: 100%; box-sizing: border-box; resize: vertical; font-family: inherit; font-size: 0.9rem; direction: rtl; margin-bottom: 6px; }
.import-panel code { background: var(--card); padding: 1px 5px; border-radius: 4px; }

/* ---- Advanced (progressive disclosure) ---- */
details.adv { margin: 10px 0 2px; border-top: 1px solid var(--border); padding-top: 10px; }
details.adv > summary { cursor: pointer; color: var(--muted); font-size: 0.86rem; list-style: none; user-select: none; padding: 4px 0; display: flex; align-items: center; gap: 6px; }
details.adv > summary::-webkit-details-marker { display: none; }
details.adv > summary::before { content: '▸'; display: inline-block; transition: transform .15s ease; }
details.adv[open] > summary::before { transform: rotate(90deg); }
details.adv > summary:hover { color: var(--text); }
.adv-body { padding-top: 8px; }

/* ---- Chapters ---- */
.hint { color: var(--muted); font-size: 0.82rem; margin: 0 0 12px; }
.chapters-head {
  display: grid;
  grid-template-columns: 1fr 84px 34px 30px 28px;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--muted);
  margin-bottom: 6px;
  padding: 0 2px;
}
.chapters { display: flex; flex-direction: column; gap: 10px; margin-bottom: 12px; }
.chapter-row {
  display: grid;
  grid-template-columns: 1fr 84px 34px 30px 28px;
  gap: 6px;
  align-items: center;
}
.btn-capture {
  background: transparent; border: 1px solid var(--border); color: var(--muted);
  border-radius: 7px; cursor: pointer; font-size: 0.95rem; line-height: 1; padding: 6px 0;
}
.btn-capture:hover { color: var(--accent); border-color: var(--accent); }
.chapter-row input[type="text"],
.chapter-row input[type="text"]::placeholder { text-align: right; }
.chapter-row .color-cell { display: flex; justify-content: center; }
.drag-handle { color: var(--muted); cursor: default; text-align: center; }

/* ---- Fields ---- */
.field-row { margin-bottom: 14px; }
.field-row.two { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
label { display: block; font-size: 0.9rem; color: var(--text); }
label small { display: block; color: var(--muted); font-size: 0.78rem; margin-top: 4px; }

input[type="text"], input[type="number"], select {
  width: 100%;
  margin-top: 6px;
  padding: 9px 10px;
  background: var(--card-2);
  border: 1px solid var(--border);
  border-radius: 9px;
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
}
input[type="range"] { width: 100%; margin-top: 8px; accent-color: var(--accent); }
input[type="color"] {
  width: 36px; height: 36px; padding: 0; border: 1px solid var(--border);
  border-radius: 8px; background: none; cursor: pointer;
}
input[type="file"] { width: 100%; margin: 8px 0; color: var(--muted); font-size: 0.85rem; }

/* ---- Buttons ---- */
.btn {
  font-family: inherit;
  font-size: 0.95rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  padding: 10px 16px;
  cursor: pointer;
  background: var(--card-2);
  color: var(--text);
  transition: filter 0.15s, opacity 0.15s;
}
.btn:hover { filter: brightness(1.15); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn-primary { background: var(--accent); border-color: var(--accent-2); color: #fff; font-weight: 600; width: 100%; }
.btn-ghost { background: transparent; border-style: dashed; width: 100%; }
.btn-icon { width: 44px; padding: 8px 0; flex: 0 0 auto; }
.btn-remove {
  background: transparent; border: none; color: var(--muted); cursor: pointer;
  font-size: 1.2rem; line-height: 1; padding: 4px;
}
.btn-remove:hover { color: #e0654a; }

/* ---- Preview ---- */
.canvas-wrap { position: relative; width: 100%; border-radius: 10px; overflow: hidden; }
.checkerboard {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(45deg, #2a2a2a 25%, transparent 25%),
    linear-gradient(-45deg, #2a2a2a 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #2a2a2a 75%),
    linear-gradient(-45deg, transparent 75%, #2a2a2a 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0;
  background-color: #1c1c1c;
}
#previewVideo {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: contain; background: #000; display: block;
}
#preview { position: relative; width: 100%; height: auto; display: block; }

.scrubber-row { display: flex; align-items: center; gap: 10px; margin-top: 12px; }
.scrubber-row input[type="range"] { flex: 1; margin-top: 0; }
.time-label { font-variant-numeric: tabular-nums; color: var(--muted); min-width: 44px; text-align: center; }

/* ---- Export ---- */
.export-option { margin-bottom: 12px; }
.export-option p { color: var(--muted); font-size: 0.85rem; margin: 4px 0 10px; }
.export-card hr { border: none; border-top: 1px solid var(--border); margin: 18px 0; }
.support-note { font-size: 0.8rem; margin-top: 8px; }
.support-note.ok { color: #58b368; }
.support-note.warn { color: #e0a84a; }

.export-status { margin-top: 16px; }
.progress-bar { width: 100%; height: 8px; background: var(--card-2); border-radius: 5px; overflow: hidden; }
.progress-fill { height: 100%; width: 0%; background: var(--accent); transition: width 0.2s; }
#exportStatusText { font-size: 0.85rem; color: var(--muted); margin-top: 8px; }

.site-footer { text-align: center; color: var(--muted); padding: 24px; font-size: 0.85rem; }
.site-footer a { color: var(--accent); }