:root {
  --bg: #f4f3ef;
  --surface: #ffffff;
  --line: #d8d6cd;
  --ink: #1d1e1a;
  --ink-dim: #6a6d63;
  --correct: #2f7a4f;
  --correct-bg: #e5f3ea;
  --partial: #a3781f;
  --partial-bg: #f6ecd6;
  --incorrect: #a63b30;
  --incorrect-bg: #f7e4e0;
  --accent: #2f5f7a;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #17191a; --surface: #202323; --line: #3a3d3a;
    --ink: #e9e7dc; --ink-dim: #9aa093;
    --correct: #6fbf8f; --correct-bg: #1b2e21;
    --partial: #d9a94a; --partial-bg: #332812;
    --incorrect: #e08a7c; --incorrect-bg: #33201d;
    --accent: #7fb3d9;
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  padding-block: 20px;
}
header {
  max-width: 760px;
  margin: 0 auto 16px;
  padding-inline: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}
.title { font-weight: 600; font-size: 15px; }
.progress { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--ink-dim); }
.bar { width: 140px; height: 6px; background: var(--line); border-radius: 4px; overflow: hidden; }
#bar-fill { height: 100%; width: 0%; background: var(--accent); transition: width 0.2s; }

main {
  max-width: 760px;
  margin: 0 auto;
  padding-inline: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.block .label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-dim);
  margin-bottom: 6px;
}
#ground-truth.big { font-size: 19px; font-weight: 600; line-height: 1.35; }
.ai-answer .row { display: flex; gap: 10px; padding: 6px 0; border-top: 1px solid var(--line); }
.ai-answer .row:first-child { border-top: none; }
.ai-answer .k { flex: 0 0 160px; color: var(--ink-dim); font-size: 13px; }
.ai-answer .v { flex: 1; font-size: 14.5px; }
#ai-differential { margin: 0; padding-left: 18px; }
#ai-differential li { margin-bottom: 3px; }

.rubric button {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  color: var(--ink-dim);
  font-size: 12.5px;
  cursor: pointer;
  padding: 4px 0;
}
#rubric-body { font-size: 12.5px; color: var(--ink-dim); line-height: 1.5; padding: 8px 0 4px; }
#rubric-body p { margin: 0 0 8px; }

.actions { display: flex; gap: 10px; }
.verdict-btn {
  flex: 1;
  padding: 16px 10px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 10px;
  border: 1.5px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.verdict-btn .key {
  font-size: 11px;
  font-weight: 700;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 6px;
}
.v-correct.active, .v-correct:hover { border-color: var(--correct); background: var(--correct-bg); color: var(--correct); }
.v-partial.active, .v-partial:hover { border-color: var(--partial); background: var(--partial-bg); color: var(--partial); }
.v-incorrect.active, .v-incorrect:hover { border-color: var(--incorrect); background: var(--incorrect-bg); color: var(--incorrect); }

.note-row input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  font-size: 13px;
}

.nav-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--ink-dim);
}
.nav-row button {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 13px;
  padding: 6px 4px;
}
.nav-row button:disabled { color: var(--ink-dim); cursor: default; }

#done-banner[hidden] { display: none; }
#done-banner {
  position: fixed; inset: 0; background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
}
.done-inner {
  background: var(--surface); border-radius: 12px; padding: 28px 32px;
  max-width: 420px; text-align: center;
}
.done-inner code { background: var(--bg); padding: 1px 5px; border-radius: 4px; font-size: 12.5px; }

/* --- login / name screens --- */
.screen[hidden] { display: none; }
#screen-login[hidden], #screen-name[hidden] { display: none; }
#screen-login, #screen-name {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.auth-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 32px 28px;
  width: 100%;
  max-width: 340px;
  text-align: center;
}
.auth-title { font-size: 19px; font-weight: 700; margin-bottom: 6px; }
.auth-sub { font-size: 13px; color: var(--ink-dim); margin: 0 0 20px; line-height: 1.5; }
#login-form, #name-form { display: flex; flex-direction: column; gap: 10px; }
#login-form input, #name-form input {
  padding: 11px 13px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  font-size: 14px;
}
#login-form button, #name-form button {
  padding: 11px;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  margin-top: 4px;
}
.auth-error { color: var(--incorrect); font-size: 12.5px; margin-top: 12px; }