/* 盐值大闯关 —— 知乎风格样式（移动端优先） */
:root {
  --zhihu-blue: #056de8;
  --zhihu-blue-dark: #0459be;
  --bg: #f6f8fa;
  --card: #ffffff;
  --text: #1a1a1a;
  --text-2: #646464;
  --line: #ebebeb;
  --good: #00965e;
  --bad: #e64340;
  --hot: #ff7a45;
  --radius: 14px;
}

* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC",
    "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

#app { max-width: 520px; margin: 0 auto; min-height: 100vh; padding: 16px; }

.screen { display: none; animation: fadein .25s ease; }
.screen.active { display: block; }
@keyframes fadein { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.hidden { display: none !important; }
.hl { color: var(--hot); }

/* ---------- 主页 ---------- */
.hero { text-align: center; padding: 44px 0 24px; }
.logo {
  width: 72px; height: 72px; margin: 0 auto 14px;
  background: var(--zhihu-blue); color: #fff;
  font-size: 42px; font-weight: 700;
  border-radius: 18px; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 8px 24px rgba(5, 109, 232, .35);
}
.hero h1 { font-size: 30px; letter-spacing: 2px; }
.slogan { color: var(--zhihu-blue); font-size: 14px; margin-top: 2px; }
.desc { color: var(--text-2); font-size: 14px; margin-top: 14px; }

.menu { display: flex; flex-direction: column; gap: 12px; margin-top: 26px; }

.btn {
  border: none; cursor: pointer; font-size: 16px;
  border-radius: var(--radius); padding: 12px 18px;
  transition: transform .06s ease, opacity .2s;
  font-family: inherit;
}
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--zhihu-blue); color: #fff; }
.btn-primary:hover { background: var(--zhihu-blue-dark); }
.btn-hot { background: linear-gradient(135deg, #ff9a44, var(--hot)); color: #fff; }
.btn-ghost { background: #fff; color: var(--zhihu-blue); border: 1px solid var(--zhihu-blue); }
.btn-big { padding: 16px 18px; text-align: left; display: flex; flex-direction: column; gap: 2px; }
.btn-title { font-size: 18px; font-weight: 600; }
.btn-sub { font-size: 12px; opacity: .85; }

.hot-tip { color: var(--bad); font-size: 13px; text-align: center; margin-top: 12px; min-height: 20px; }
.footer { text-align: center; color: #aaa; font-size: 12px; margin-top: 40px; }

/* ---------- 卡片 ---------- */
.card {
  background: var(--card); border-radius: var(--radius);
  padding: 18px; box-shadow: 0 2px 10px rgba(0, 0, 0, .05);
  margin-top: 14px;
}

/* ---------- 答题 ---------- */
.quiz-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 2px; font-size: 14px;
}
.lives { letter-spacing: 2px; font-size: 15px; }
.progress-text { color: var(--text-2); }
.score-chip {
  background: #e8f1fd; color: var(--zhihu-blue);
  border-radius: 999px; padding: 3px 12px; font-size: 13px;
}
.score-chip b { font-size: 15px; }

.timer-track { height: 6px; background: #e4e8ec; border-radius: 999px; overflow: hidden; }
.timer-bar { height: 100%; width: 100%; background: var(--zhihu-blue); border-radius: 999px; transition: width .1s linear; }
.timer-bar.urgent { background: var(--bad); }

.combo-banner { min-height: 22px; text-align: center; color: var(--hot); font-size: 13px; font-weight: 600; margin-top: 4px; }

.q-meta { display: flex; gap: 8px; margin-bottom: 10px; }
.tag {
  background: #e8f1fd; color: var(--zhihu-blue);
  font-size: 12px; border-radius: 6px; padding: 2px 8px;
}
.tag-diff { background: #fff3e8; color: var(--hot); }
.q-text { font-size: 19px; line-height: 1.5; margin-bottom: 16px; }

.options { display: flex; flex-direction: column; gap: 10px; }
.option-btn {
  text-align: left; font-size: 16px; font-family: inherit;
  background: #f4f6f8; border: 2px solid transparent;
  border-radius: 10px; padding: 12px 14px; cursor: pointer;
  transition: border-color .15s, background .15s;
}
.option-btn:hover:not(:disabled) { border-color: var(--zhihu-blue); background: #eef5fe; }
.option-btn.right { border-color: var(--good); background: #e6f7f0; color: var(--good); font-weight: 600; }
.option-btn.wrong { border-color: var(--bad); background: #fdecec; color: var(--bad); }
.option-btn.removed { opacity: .35; text-decoration: line-through; }
.option-btn:disabled { cursor: default; }

.items-bar { display: flex; gap: 10px; margin-top: 12px; }
.item-btn {
  flex: 1; background: #fff; border: 1px dashed #c3cdd8;
  border-radius: 10px; padding: 9px; font-size: 13px; color: var(--text-2);
  cursor: pointer; font-family: inherit;
}
.item-btn:disabled { opacity: .4; cursor: not-allowed; }
.item-btn b { color: var(--zhihu-blue); }

.explain-card { border-left: 4px solid var(--zhihu-blue); }
.explain-verdict { font-weight: 700; font-size: 15px; }
.explain-verdict.good { color: var(--good); }
.explain-verdict.bad { color: var(--bad); }
.explain-text { color: var(--text-2); font-size: 14px; margin: 8px 0 4px; }
.explain-card .btn { width: 100%; margin-top: 12px; }

.related { margin-top: 10px; }
.related-title { font-size: 13px; color: var(--text-2); margin-bottom: 6px; }
.related-loading { font-size: 12px; color: #a5adb5; }
.related-item {
  display: block; text-decoration: none;
  background: #f4f8fe; border-radius: 8px;
  padding: 8px 10px; margin-bottom: 6px;
}
.related-item-title { display: block; color: var(--zhihu-blue); font-size: 14px; }
.related-item-meta { display: block; color: #9aa4ae; font-size: 12px; margin-top: 2px; }

/* ---------- 热榜 PK ---------- */
.hot-question { font-size: 18px; text-align: center; margin: 18px 0 4px; }
.hot-stale { color: var(--hot); font-size: 12px; text-align: center; margin-top: 8px; }

.pk-wrap { display: flex; flex-direction: column; gap: 8px; margin-top: 14px; position: relative; }
.pk-card {
  background: var(--card); border: 2px solid var(--line);
  border-radius: var(--radius); padding: 18px 16px;
  font-size: 16px; text-align: left; cursor: pointer; font-family: inherit;
  transition: border-color .15s, transform .06s;
  min-height: 84px;
}
.pk-card:hover:not(:disabled) { border-color: var(--hot); }
.pk-card:active { transform: scale(.98); }
.pk-title { display: block; font-weight: 600; line-height: 1.5; }
.pk-summary { display: block; color: var(--text-2); font-size: 12px; margin-top: 6px; }
.pk-vs {
  align-self: center; background: var(--hot); color: #fff;
  font-weight: 800; font-size: 13px;
  border-radius: 999px; padding: 3px 14px;
  margin: -4px 0;
  z-index: 1;
}
.pk-card.pk-win { border-color: var(--good); background: #f0fbf6; }
.pk-card.pk-lose { border-color: var(--line); opacity: .6; }
.pk-card:disabled { cursor: default; }
.hot-links { margin-top: 10px; }

/* ---------- 结算 ---------- */
.result-card { text-align: center; margin-top: 40px; padding: 30px 20px; }
.result-badge { font-size: 56px; }
.result-card h2 { font-size: 22px; margin-top: 8px; }
.result-score { color: var(--text-2); margin-top: 6px; }
.result-score b { color: var(--zhihu-blue); font-size: 34px; margin-left: 4px; }
.result-stats { color: var(--text-2); font-size: 13px; margin-top: 10px; }

.submit-row { display: flex; gap: 8px; margin-top: 20px; }
.submit-row input {
  flex: 1; border: 1px solid #cdd5dd; border-radius: 10px;
  padding: 10px 12px; font-size: 15px; font-family: inherit; outline: none;
}
.submit-row input:focus { border-color: var(--zhihu-blue); }
.submit-msg { min-height: 20px; font-size: 13px; color: var(--zhihu-blue); margin-top: 8px; }

.result-actions { display: flex; gap: 8px; margin-top: 14px; }
.result-actions .btn { flex: 1; font-size: 14px; padding: 10px 6px; }

/* ---------- 排行榜 ---------- */
.board-title { text-align: center; margin-top: 24px; }
.board-card { padding: 8px 16px; }
.board-list { list-style: none; }
.board-item {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 0; border-bottom: 1px solid var(--line);
}
.board-item:last-child { border-bottom: none; }
.board-rank { width: 34px; text-align: center; font-size: 17px; font-weight: 700; color: var(--text-2); }
.board-name { flex: 1; font-size: 15px; font-weight: 600; }
.board-name em { display: block; font-style: normal; font-weight: 400; font-size: 12px; color: #9aa4ae; }
.board-score { color: var(--zhihu-blue); font-weight: 700; }
.board-empty { text-align: center; color: #9aa4ae; padding: 24px 0; font-size: 14px; }
#screen-board .btn { width: 100%; margin-top: 14px; }

@media (min-width: 520px) {
  .pk-wrap { flex-direction: row; align-items: stretch; }
  .pk-card { flex: 1; }
  .pk-vs { align-self: center; margin: 0 -6px; }
}