:root {
  --bg: #f4f5fb;
  --surface: #ffffff;
  --border: #e3e5ef;
  --text: #1c1e26;
  --muted: #6b7080;
  --accent: #4f46e5;
  --accent-hover: #4338ca;
  --accent-soft: #eef0ff;
  --danger: #dc2626;
  --success: #16a34a;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(20, 22, 40, 0.07), 0 8px 24px rgba(20, 22, 40, 0.06);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

.container { max-width: 960px; margin: 0 auto; padding: 24px 16px 64px; }

.topbar {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 10;
}
.topbar .brand { font-weight: 700; font-size: 17px; }
.topbar .brand span { color: var(--accent); }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
  margin-bottom: 16px;
}

h1 { font-size: 26px; margin: 0 0 6px; }
h2 { font-size: 20px; margin: 0 0 14px; }
h3 { font-size: 16px; margin: 0 0 8px; }
p.muted, .muted { color: var(--muted); }
.small { font-size: 13px; }

label.field-label { display: block; font-weight: 600; font-size: 14px; margin: 14px 0 5px; }
label.field-label .req { color: var(--danger); }

input[type="text"], input[type="email"], input[type="password"], input[type="number"], input[type="url"], select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  background: #fff;
  color: var(--text);
}
input:focus, select:focus, textarea:focus {
  outline: 2px solid var(--accent-soft);
  border-color: var(--accent);
}
textarea { min-height: 110px; resize: vertical; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 8px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  background: var(--accent);
  color: #fff;
  transition: background 0.15s;
}
.btn:hover { background: var(--accent-hover); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.secondary { background: var(--surface); color: var(--text); border-color: var(--border); }
.btn.secondary:hover { background: var(--accent-soft); }
.btn.danger { background: #fff; color: var(--danger); border-color: #f3c1c1; }
.btn.danger:hover { background: #fdf1f1; }
.btn.small { padding: 6px 12px; font-size: 13px; }
.btn.big { padding: 14px 28px; font-size: 17px; }

.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.row.between { justify-content: space-between; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 16px; }
@media (max-width: 640px) { .grid-2 { grid-template-columns: 1fr; } }

.error-msg { color: var(--danger); font-size: 14px; margin-top: 10px; min-height: 1em; }

.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  background: var(--accent-soft);
  color: var(--accent);
}
.badge.green { background: #e8f7ee; color: var(--success); }
.badge.gray { background: #eef0f4; color: var(--muted); }
.badge.orange { background: #fef3e2; color: #b45309; }

table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  background: var(--surface);
}
table.data th, table.data td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
  white-space: nowrap;
}
table.data td.wrap { white-space: normal; min-width: 180px; max-width: 340px; }
table.data th { font-size: 12px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.table-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }

.hidden { display: none !important; }

/* ---------- question builder ---------- */
.q-card {
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 14px;
  background: #fbfbfe;
}
.q-card .q-head { display: flex; gap: 10px; flex-wrap: wrap; }
.q-card .q-head input[type="text"] { flex: 2 1 260px; }
.q-card .q-head select { flex: 1 1 150px; width: auto; }
.q-options { margin-top: 10px; }
.q-option-row { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.q-option-row .dot { width: 14px; height: 14px; border: 2px solid #c3c6d4; border-radius: 50%; flex: none; }
.q-option-row .dot.square { border-radius: 3px; }
.q-option-row input { flex: 1; }
.q-foot { display: flex; justify-content: flex-end; align-items: center; gap: 14px; margin-top: 12px; border-top: 1px solid var(--border); padding-top: 10px; }
.icon-btn {
  border: none; background: none; cursor: pointer; font-size: 16px;
  color: var(--muted); padding: 4px 6px; border-radius: 6px;
}
.icon-btn:hover { background: var(--accent-soft); color: var(--accent); }
.toggle { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; cursor: pointer; user-select: none; }

.share-box {
  display: flex; gap: 8px; align-items: center;
  background: var(--accent-soft);
  border: 1px dashed var(--accent);
  padding: 10px 14px; border-radius: 10px;
  margin: 10px 0;
}
.share-box code { font-size: 13px; word-break: break-all; flex: 1; }

.steps { display: flex; gap: 8px; margin-bottom: 18px; font-size: 13px; font-weight: 600; }
.steps .step { padding: 5px 14px; border-radius: 999px; background: #eef0f4; color: var(--muted); }
.steps .step.active { background: var(--accent); color: #fff; }

/* ---------- user task page ---------- */
.center-wrap { max-width: 760px; margin: 0 auto; padding: 28px 16px 64px; }

.modal-backdrop {
  position: fixed; inset: 0;
  background: rgba(18, 20, 32, 0.55);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  z-index: 50; padding: 16px;
}
.modal {
  background: var(--surface);
  border-radius: 16px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.25);
  padding: 28px;
  width: 100%; max-width: 460px;
}

/* Video mode: the whole page is locked to the viewport — no scrolling.
   The player is sized to fill ~the whole screen while the title, controls
   and lock note always stay visible. */
body.video-mode {
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}
body.video-mode .topbar { flex: none; }
body.video-mode .center-wrap {
  flex: 1;
  min-height: 0;
  max-width: none;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
}
#stage-video {
  width: min(94vw, calc((100vh - 230px) * 16 / 9));
  max-width: 100%;
}
#stage-video .card { padding: 14px 16px 16px; margin: 0; }
#stage-video h2 {
  font-size: 17px;
  margin-bottom: 10px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.video-shell {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
  border-radius: 12px;
  overflow: hidden;
}
/* The iframe is deliberately 240px taller than the visible shell: YouTube
   letterboxes the video and draws its title / share / "More videos" overlays
   in the top and bottom bars, which end up cropped out of view. The video
   itself always spans the full width, so no content is lost. */
.video-shell iframe {
  position: absolute;
  top: 50%;
  left: 0;
  width: 100%;
  height: calc(100% + 240px);
  transform: translateY(-50%);
}
.video-guard {
  position: absolute; inset: 0;
  z-index: 5;
  cursor: pointer;
  background: transparent;
}
/* Opaque pause cover: hides YouTube's paused-state overlays ("More videos",
   channel avatar, title cards). JS sets the video's own thumbnail as its
   background, so pausing shows a clean dimmed poster instead. */
.video-guard .big-play {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: #000;
  background-size: cover;
  background-position: center;
  transition: opacity 0.2s;
}
.video-guard .big-play .circle {
  width: 84px; height: 84px; border-radius: 50%;
  background: var(--accent);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 34px;
  box-shadow: 0 8px 30px rgba(0,0,0,0.4);
}
/* In-video timed question popup (lives inside .video-shell so it also
   shows in fullscreen) */
.quiz-overlay {
  position: absolute;
  inset: 0;
  z-index: 10;
  background: rgba(10, 11, 20, 0.72);
  backdrop-filter: blur(3px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
}
.quiz-box {
  background: var(--surface);
  border-radius: 14px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  padding: 22px 24px;
  width: 100%;
  max-width: 520px;
  max-height: 92%;
  overflow-y: auto;
}
.quiz-box h3 { font-size: 17px; margin-bottom: 12px; }
.quiz-box .toggle { display: flex; margin: 8px 0; }
.quiz-q { margin-bottom: 16px; }
.quiz-q-label { font-weight: 600; font-size: 14.5px; margin-bottom: 6px; }

/* admin: timestamp input + section cards in the builder */
.q-time-input { width: 90px !important; padding: 6px 10px !important; }
.section-card {
  border: 1px solid var(--border);
  border-left: 4px solid #eab308;
  border-radius: 10px;
  padding: 16px;
  margin-bottom: 14px;
  background: #fffdf5;
}
.section-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.section-head input[type="text"]:first-child { flex: 1 1 260px; font-weight: 600; }
.section-card .q-card { background: #fff; }

/* ---- YouTube-style overlaid player controls ---- */
.yt-controls {
  position: absolute; left: 0; right: 0; bottom: 0;
  z-index: 6;
  padding: 18px 14px 8px;
  background: linear-gradient(to top,
    rgba(0, 0, 0, 0.78) 0%, rgba(0, 0, 0, 0.45) 45%, rgba(0, 0, 0, 0) 100%);
  opacity: 1;
  transition: opacity 0.25s ease;
  -webkit-user-select: none; user-select: none;
}
/* Auto-hide while the video is playing, reveal on hover (like YouTube). */
.video-shell.playing .yt-controls { opacity: 0; pointer-events: none; }
.video-shell.playing:hover .yt-controls,
.video-shell.playing .yt-controls:focus-within { opacity: 1; pointer-events: auto; }
.video-shell.playing:hover { cursor: default; }

.yt-controls-row { display: flex; align-items: center; gap: 4px; }
.yt-left { display: flex; align-items: center; gap: 2px; }
.yt-right { display: flex; align-items: center; gap: 4px; margin-left: auto; }

.yt-btn {
  background: transparent; border: none; color: #fff; cursor: pointer;
  width: 40px; height: 40px; border-radius: 50%;
  font-size: 18px; line-height: 1; padding: 0;
  display: flex; align-items: center; justify-content: center;
  transition: background 0.15s ease;
}
.yt-btn:hover { background: rgba(255, 255, 255, 0.18); }

/* Action row below the player (holds the "Next" button once the video ends). */
.video-actions { display: flex; justify-content: flex-end; margin-top: 12px; }

/* Fullscreen mode for the player card (triggered by the ⛶ button) */
#videoCard:fullscreen,
#videoCard:-webkit-full-screen {
  background: #000;
  border: none;
  border-radius: 0;
  display: flex;
  flex-direction: column;
  padding: 0;
}
#videoCard:fullscreen h2,
#videoCard:-webkit-full-screen h2 { display: none; }
#videoCard:fullscreen .video-shell,
#videoCard:-webkit-full-screen .video-shell {
  flex: 1;
  min-height: 0;
  border-radius: 0;
  aspect-ratio: auto;
}
#videoCard:fullscreen #videoNote,
#videoCard:-webkit-full-screen #videoNote { display: none; }

/* Scrubber: thin red YouTube-style bar that thickens on hover. */
.yt-controls .progress-track {
  width: 100%; height: 4px; border-radius: 2px;
  background: rgba(255, 255, 255, 0.32);
  margin-bottom: 4px; overflow: visible; position: relative;
  transition: height 0.1s ease;
}
.yt-controls .progress-track.seekable { cursor: pointer; }
.yt-controls .progress-track:hover { height: 6px; }
.yt-controls .progress-fill {
  height: 100%; width: 0%; background: #ff0000; border-radius: 2px;
  position: relative; transition: width 0.2s linear;
}
.progress-thumb {
  position: absolute; right: -6px; top: 50%;
  width: 13px; height: 13px; border-radius: 50%; background: #ff0000;
  transform: translateY(-50%) scale(0);
  transition: transform 0.1s ease;
}
.yt-controls .progress-track:hover .progress-thumb { transform: translateY(-50%) scale(1); }
.yt-controls .time-label {
  color: #fff; font-size: 13px; margin-left: 8px;
  font-variant-numeric: tabular-nums; white-space: nowrap;
}

.notice {
  background: #fffaeb; border: 1px solid #fbe6a2; color: #92600a;
  border-radius: 10px; padding: 10px 14px; font-size: 14px; margin: 12px 0;
}

.thanks { text-align: center; padding: 60px 20px; }
.thanks .check {
  width: 92px; height: 92px; margin: 0 auto 22px;
  border-radius: 50%; background: #e8f7ee; color: var(--success);
  display: flex; align-items: center; justify-content: center; font-size: 44px;
}

.instructions-body { white-space: pre-wrap; font-size: 15.5px; }

/* user: thumbnail choice page */
.thumb-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin: 18px 0;
}
.thumb-rating-block {
  margin: 8px 0 18px;
  padding-top: 12px;
  border-top: 1px solid var(--border, #e6e8f0);
}
.thumb-option {
  border: 2px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  cursor: pointer;
  background: var(--surface);
  transition: border-color 0.15s, transform 0.1s;
}
.thumb-option:hover { transform: translateY(-2px); }
.thumb-option.selected { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.thumb-option img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; display: block; }
.thumb-option .thumb-title {
  padding: 10px 12px;
  font-weight: 600;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.thumb-option.selected .thumb-title::before { content: '✔'; color: var(--accent); }

/* admin: thumbnail builder cards */
.thumb-card {
  display: flex;
  gap: 14px;
  border: 1px solid var(--border);
  border-left: 4px solid #0ea5e9;
  border-radius: 10px;
  padding: 14px;
  margin-bottom: 12px;
  background: #f8fcff;
  flex-wrap: wrap;
}
.thumb-preview {
  width: 200px;
  aspect-ratio: 16 / 9;
  background: #e8eaf1;
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 13px;
  flex: none;
}
.thumb-preview img { width: 100%; height: 100%; object-fit: cover; }
.thumb-fields { flex: 1 1 260px; display: flex; flex-direction: column; gap: 8px; }

/* star rating question (5 stars, half-star steps) */
.star-rating {
  display: flex; align-items: center; gap: 6px;
  margin-top: 10px; user-select: none;
}
.star-rating .star {
  position: relative; font-size: 34px; line-height: 1; cursor: pointer;
}
.star-rating .star-base { color: #d5d8e4; }
.star-rating .star-fill {
  position: absolute; left: 0; top: 0; width: 0;
  overflow: hidden; white-space: nowrap;
  color: #eab308; pointer-events: none;
}
.star-rating .star-hit { position: absolute; top: 0; width: 50%; height: 100%; }
.star-rating .star-hit.left { left: 0; }
.star-rating .star-hit.right { right: 0; }
.star-rating-value {
  margin-left: 8px; font-size: 14px; color: var(--muted);
  min-width: 52px; font-variant-numeric: tabular-nums;
}

/* admin: question & answer view inside the submission modal */
/* Grouped answer sections in the submission detail modal */
.qa-section {
  margin: 18px 0;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}
.qa-section:first-child { border-top: none; padding-top: 0; }
.qa-section-title {
  font-size: 14px; font-weight: 700; color: var(--accent);
  margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.02em;
}
.qa-thumb-wrap {
  position: relative; display: inline-block; max-width: 260px; width: 100%;
  cursor: zoom-in; border-radius: 8px; overflow: hidden;
}
.qa-thumb {
  width: 100%; border-radius: 8px; border: 1px solid var(--border); display: block;
}
/* Hover hint: lighten the thumbnail and show a fullscreen icon in the middle. */
.qa-thumb-overlay {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(255, 255, 255, 0.15);
  opacity: 0; transition: opacity 0.15s ease;
}
.qa-thumb-wrap:hover .qa-thumb-overlay { opacity: 1; }
.qa-thumb-overlay span {
  width: 54px; height: 54px; border-radius: 50%;
  background: rgba(0, 0, 0, 0.55); color: #fff; font-size: 25px;
  display: flex; align-items: center; justify-content: center;
}
/* Full-screen image viewer for the selected thumbnail */
.img-lightbox {
  position: fixed; inset: 0; z-index: 1000;
  background: rgba(0, 0, 0, 0.9);
  display: flex; align-items: center; justify-content: center;
  padding: 24px; cursor: zoom-out;
}
.img-lightbox img {
  max-width: 100%; max-height: 100%;
  border-radius: 8px; box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}
.qa { margin: 14px 0; }
.qa-q { font-weight: 600; font-size: 14px; margin-bottom: 4px; }
.qa-a {
  background: #f6f7fb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 14px;
  white-space: pre-wrap;
  word-break: break-word;
}