:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #1d2230;
  --muted: #6b7280;
  --border: #e5e7eb;
  --primary: #2563eb;
  --primary-fg: #ffffff;
  --selected: #10b981;
  --selected-bg: #ecfdf5;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 12px rgba(0,0,0,.05);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui,
               Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
code { background: #f0f1f4; padding: 1px 5px; border-radius: 4px; font-size: .9em; }
.muted { color: var(--muted); }
.small { font-size: .85em; }

/* ---------- Landing ---------- */
.landing {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}
.landing-card {
  background: var(--card);
  border-radius: 12px;
  padding: 32px;
  width: 100%;
  max-width: 520px;
  box-shadow: var(--shadow);
}
.landing-card h1 { margin: 0 0 8px; font-size: 1.6rem; }
.start-form { display: grid; gap: 18px; margin: 24px 0 16px; }
.start-form label > span {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
}
.start-form input[type=text] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 1rem;
}
.start-form fieldset {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 14px;
}
.start-form fieldset legend { font-weight: 600; padding: 0 6px; }
.start-form .radio {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 0;
}
button.primary {
  background: var(--primary);
  color: var(--primary-fg);
  border: none;
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}
button.primary:hover { filter: brightness(1.05); }

/* ---------- Annotate ---------- */
.annotate { padding: 0 0 80px; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 12px;
  padding: 10px 18px;
  background: rgba(255,255,255,.95);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}
.topbar-left { display: flex; align-items: center; gap: 14px; }
.topbar-right { display: flex; align-items: center; gap: 12px; justify-content: flex-end; }
.home-link { font-weight: 600; }
.test-label { font-weight: 600; }
.progress { font-size: 1rem; }
.annotator-tag {
  background: #eef2ff;
  color: #3730a3;
  padding: 3px 10px;
  border-radius: 999px;
  font-size: .85rem;
  font-weight: 600;
}
.jump-form input {
  width: 90px;
  padding: 6px 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: .9rem;
}

.request-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 20px;
  margin: 18px;
  box-shadow: var(--shadow);
}
.request-box h2 { margin: 0 0 8px; font-size: 1rem; }
.request-box p { margin: 0; }
.request-box details { margin-top: 10px; }
.request-box details summary { cursor: pointer; color: var(--muted); }
.request-box details ul { margin: 8px 0 0 18px; }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  padding: 0 18px;
}
.ui-card {
  margin: 0;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}
.ui-card figcaption {
  padding: 8px 12px;
  font-weight: 700;
  font-size: .95rem;
  background: #f9fafb;
  border-bottom: 1px solid var(--border);
}
.ui-card img {
  width: 100%;
  height: auto;
  display: block;
  background: #fafafa;
}

.rating {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  margin: 18px;
  padding: 16px 20px;
  box-shadow: var(--shadow);
}
.rating h3 { margin: 0 0 12px; font-size: 1rem; }
.rating-buttons {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
}
.choice {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px 8px;
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  font: inherit;
  transition: border-color .12s, background .12s, transform .05s;
}
.choice:hover { border-color: var(--primary); }
.choice:active { transform: scale(.98); }
.choice.selected {
  border-color: var(--selected);
  background: var(--selected-bg);
}
.choice .key {
  font-size: .8rem;
  font-weight: 700;
  color: var(--muted);
  background: #f3f4f6;
  border-radius: 4px;
  padding: 1px 6px;
}
.choice .lbl { font-weight: 700; }
.choice .desc { font-size: .8rem; color: var(--muted); text-align: center; }
.status { margin: 12px 0 0; }

.navbar {
  display: flex;
  justify-content: space-between;
  padding: 0 18px;
  margin-top: 8px;
}
.nav {
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  font-weight: 600;
}
.nav.disabled { color: var(--muted); background: #f3f4f6; pointer-events: none; }