:root {
  --ink: #1a2a28;
  --muted: #5c706d;
  --paper: #f2f6f4;
  --panel: #ffffff;
  --accent: #0d7a6f;
  --accent-deep: #08574f;
  --warm: #e8a54b;
  --line: #d4e2de;
  --ok: #2f8f5b;
  --danger: #a94442;
  --shadow: 0 10px 28px rgba(26, 42, 40, 0.08);
  --radius: 18px;
  --font: "Avenir Next", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --font-en: Georgia, "Times New Roman", serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  min-height: 100vh;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1000px 420px at 8% -8%, #d7efe8 0%, transparent 55%),
    radial-gradient(820px 380px at 100% 0%, #ffe9cb 0%, transparent 48%),
    var(--paper);
}

a { color: var(--accent-deep); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap {
  width: min(820px, 100%);
  margin: 0 auto;
  padding: 22px 16px 56px;
}

header.app-header h1 {
  margin: 0 0 6px;
  font-size: clamp(1.55rem, 4.5vw, 2.05rem);
  letter-spacing: 0.02em;
}
header.app-header p {
  margin: 0;
  color: var(--muted);
  line-height: 1.5;
}

.nav-tabs {
  display: flex;
  gap: 8px;
  margin: 16px 0 0;
  flex-wrap: wrap;
}
.nav-tabs button {
  border: 1px solid var(--line);
  background: #fafcfb;
  color: var(--muted);
  border-radius: 999px;
  padding: 8px 14px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.nav-tabs button.active {
  background: #eef8f5;
  color: var(--accent-deep);
  border-color: #9fd0c8;
}
.nav-tabs a.nav-tab-link {
  border: 1px solid var(--line);
  background: #fff8ef;
  color: #3a2508;
  border-radius: 999px;
  padding: 8px 14px;
  font: inherit;
  font-weight: 700;
  text-decoration: none;
}
.nav-tabs a.nav-tab-link:hover {
  border-color: #f0c48a;
  text-decoration: none;
}

.panel {
  margin-top: 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}

.card-list {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}

.card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
  color: inherit;
  text-decoration: none;
  transition: transform 0.12s ease, border-color 0.15s ease;
}
.card:hover {
  transform: translateY(-1px);
  border-color: #9fd0c8;
  text-decoration: none;
}
.card h2 {
  margin: 0 0 6px;
  font-size: 1.15rem;
}
.card .meta {
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.45;
}
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}
.tag {
  font-size: 0.78rem;
  color: var(--accent-deep);
  background: #e5f4f0;
  border-radius: 999px;
  padding: 3px 9px;
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 12px;
  align-items: center;
}

label.chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
  user-select: none;
  color: var(--muted);
  background: #fafcfb;
  font-size: 0.95rem;
}
label.chip:has(input:checked) {
  color: var(--accent-deep);
  border-color: #9fd0c8;
  background: #eef8f5;
  font-weight: 600;
}
label.chip input { accent-color: var(--accent); }

.stage {
  margin-top: 14px;
  min-height: 200px;
  border-radius: calc(var(--radius) - 4px);
  border: 1px dashed #b9d4ce;
  background: linear-gradient(180deg, #fbfffd 0%, #f4fbf8 100%);
  padding: 20px 16px;
  text-align: center;
}
.badge {
  display: inline-block;
  font-size: 0.85rem;
  color: var(--accent-deep);
  background: #dff3ee;
  padding: 4px 10px;
  border-radius: 999px;
  margin-bottom: 10px;
}
.prompt {
  margin: 0 0 8px;
  color: var(--muted);
  min-height: 1.4em;
}
.big {
  font-family: var(--font-en);
  font-size: clamp(1.3rem, 4.2vw, 1.85rem);
  line-height: 1.35;
  margin: 8px 0 0;
  min-height: 2.5em;
  word-break: break-word;
}
.big.blur {
  filter: blur(7px);
  user-select: none;
}

.progress {
  margin-top: 12px;
  height: 8px;
  background: #e4eeeb;
  border-radius: 999px;
  overflow: hidden;
}
.progress > i {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), #3aa895);
  transition: width 0.25s ease;
}
.meta-line {
  margin-top: 8px;
  display: flex;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.9rem;
  gap: 8px;
}

.controls {
  margin-top: 14px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
@media (min-width: 560px) {
  .controls { grid-template-columns: repeat(4, 1fr); }
}

button.btn {
  appearance: none;
  border: 0;
  border-radius: 14px;
  padding: 14px 12px;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.12s ease, opacity 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}
button.btn:active { transform: scale(0.98); }
button.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
}
.btn-start { background: var(--accent); color: #fff; }
.btn-next { background: var(--warm); color: #3a2508; }
.btn-replay { background: #e8f1ef; color: var(--ink); }
.btn-stop { background: #f1e6e4; color: #6b2f28; }
.btn-link {
  display: inline-block;
  margin-top: 10px;
  background: #e8f1ef;
  color: var(--ink);
  border-radius: 12px;
  padding: 10px 14px;
  font-weight: 700;
}

.hint {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.5;
}

details.answers {
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  padding: 12px 16px;
}
details.answers summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--accent-deep);
}
details.answers ol {
  margin: 10px 0 0;
  padding-left: 1.2em;
  line-height: 1.7;
  font-family: var(--font-en);
}

.empty {
  color: var(--muted);
  padding: 18px 4px;
  line-height: 1.55;
}

.footer-note {
  margin-top: 22px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.5;
}

.back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 10px;
  font-weight: 700;
  color: var(--accent-deep);
}