/* 六智宝库 - 关于页专用样式
   视觉基准：home/antacid.html
   数据条数字复用站点的 pH 三色渐变 #C73E2A → #C89F3D → #1E6B6E */

.about-content {
  max-width: 900px;
  margin: 0 auto 4rem;
  padding: 0 1.5rem;
}

/* ---------- 数据条 ---------- */
.about-stats {
  display: grid;
  /* auto-fit：桌面 4 项一行，窄屏自动折成 2 列，无需额外断点 */
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-bottom: 2.6rem;
}
.stat {
  --tone: var(--primary);
  padding: 1.35rem 1rem 1.2rem;
  text-align: center;
  border-radius: 14px;
  border: 1px solid var(--card-border);
  background: var(--card);
  box-shadow: var(--card-shadow);
}
.stat b {
  display: block;
  font-family: 'Fraunces', 'Songti SC','Source Han Serif SC','SimSun', serif;
  font-size: 2.1rem; font-weight: 700; line-height: 1.1;
  /* 每个数字用自己的色相做深色渐变，避免整行都落在浅金上而发灰 */
  background: linear-gradient(135deg, var(--tone), color-mix(in srgb, var(--tone) 58%, #4A3410));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat span {
  display: block; margin-top: .35rem;
  font-size: .78rem; font-weight: 600; letter-spacing: .06em;
  color: var(--muted);
}

/* ---------- 内容区块 ---------- */
.about-block { margin-bottom: 2.5rem; }
.about-block > h2 {
  display: flex; align-items: center; gap: .6rem;
  font-family: 'Fraunces', 'Songti SC','Source Han Serif SC','SimSun', serif;
  font-size: 1.3rem; font-weight: 700; letter-spacing: -.01em;
  margin-bottom: .95rem;
}
.about-block > h2::before {
  content: ''; flex-shrink: 0;
  width: 4px; height: 1.15rem; border-radius: 2px;
  background: linear-gradient(180deg, #C73E2A, #1E6B6E);
}
.about-block > p {
  color: var(--muted);
  font-size: .95rem; line-height: 1.85;
}

/* ---------- 场景进度行 ---------- */
.progress-list { display: flex; flex-direction: column; gap: .7rem; }

.progress-row {
  --tone: var(--primary);
  display: flex; align-items: center; gap: .95rem;
  padding: 1.05rem 1.3rem;
  border-radius: 14px;
  border: 1px solid var(--card-border);
  background:
    linear-gradient(90deg, color-mix(in srgb, var(--tone) 6%, transparent), transparent 55%),
    var(--card);
  box-shadow: var(--card-shadow);
  text-decoration: none; color: inherit;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), border-color .25s;
}
a.progress-row:hover {
  transform: translateX(4px);
  border-color: color-mix(in srgb, var(--tone) 32%, transparent);
  box-shadow: 0 18px 38px -26px color-mix(in srgb, var(--tone) 48%, rgba(44, 31, 18, .45));
}
.progress-icon {
  display: grid; place-items: center;
  width: 40px; height: 40px; flex-shrink: 0;
  border-radius: 11px; font-size: 1.1rem; line-height: 1;
  background: color-mix(in srgb, var(--tone) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--tone) 24%, transparent);
}
.progress-main { display: flex; flex-direction: column; gap: .2rem; min-width: 0; }
.progress-main strong { font-size: .98rem; font-weight: 700; }
.progress-main span { font-size: .82rem; color: var(--muted); line-height: 1.5; }
.progress-state {
  margin-left: auto; flex-shrink: 0;
  font-size: .72rem; font-weight: 700; letter-spacing: .04em;
  padding: .24rem .62rem; border-radius: 999px;
}
.progress-state.is-live {
  color: var(--tone);
  background: color-mix(in srgb, var(--tone) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--tone) 24%, transparent);
}
.progress-state.is-soon {
  color: var(--muted);
  background: rgba(111, 90, 71, .10);
  border: 1px solid rgba(111, 90, 71, .20);
}

/* ---------- 技术特点 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}
.feature-item {
  padding: 1.25rem 1.3rem;
  border-radius: 14px;
  border: 1px solid var(--card-border);
  background: var(--card);
  box-shadow: var(--card-shadow);
  transition: transform .25s var(--ease), box-shadow .25s var(--ease),
              border-color .25s;
}
.feature-item:hover {
  transform: translateY(-4px);
  border-color: color-mix(in srgb, var(--primary) 26%, transparent);
  box-shadow: 0 20px 42px -24px rgba(44, 31, 18, .42);
}
.feature-item h3 {
  display: flex; align-items: center; gap: .45rem;
  font-size: .95rem; font-weight: 700;
  margin-bottom: .45rem;
}
.feature-item p {
  font-size: .84rem; line-height: 1.68;
  color: var(--muted);
}

/* ---------- 常见问题（FAQ）----------
   用 <details> 折叠：答案文本始终留在 HTML 里，搜索引擎与 AI 抓取器都能读到；
   首个条目默认展开，保证正文中永远有一段完整的问答可见。 */
.faq-list { display: flex; flex-direction: column; gap: .65rem; }

.faq-item {
  position: relative;
  border-radius: 14px;
  border: 1px solid var(--card-border);
  background: var(--card);
  box-shadow: var(--card-shadow);
  overflow: hidden;
  transition: border-color .25s var(--ease);
}
.faq-item:hover { border-color: color-mix(in srgb, var(--primary) 26%, transparent); }
.faq-item[open] { border-color: color-mix(in srgb, var(--primary) 24%, transparent); }

.faq-item > summary {
  position: relative;
  cursor: pointer;
  list-style: none;
  padding: .95rem 2.6rem .95rem 1.2rem;
  font-size: .93rem; font-weight: 600; line-height: 1.5;
  color: var(--fg);
}
.faq-item > summary::-webkit-details-marker { display: none; }
.faq-item > summary:focus-visible { outline: 2px solid var(--primary); outline-offset: -2px; }

/* 展开指示符（纯 CSS 箭头） */
.faq-item > summary::after {
  content: '';
  position: absolute; right: 1.3rem; top: 50%;
  width: .5rem; height: .5rem;
  margin-top: -.34rem;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: rotate(45deg);
  transition: transform .25s var(--ease), margin-top .25s, border-color .25s;
}
.faq-item[open] > summary::after {
  transform: rotate(-135deg);
  margin-top: -.14rem;
  border-color: var(--primary);
}

.faq-answer { padding: 0 1.2rem 1.05rem; }
.faq-answer p { font-size: .88rem; line-height: 1.8; color: var(--muted); }
.faq-answer p + p { margin-top: .6rem; }
.faq-answer code {
  font-family: 'JetBrains Mono', ui-monospace, monospace;
  font-size: .85em;
  padding: .08em .4em; border-radius: 4px;
  background: rgba(44, 31, 18, .07);
  color: var(--fg);
}

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  .about-stats { gap: .7rem; margin-bottom: 2.1rem; }
  .stat { padding: 1.05rem .6rem .95rem; border-radius: 12px; }
  .stat b { font-size: 1.6rem; }
  .stat span { font-size: .72rem; }
  .about-block { margin-bottom: 2rem; }
  .about-block > h2 { font-size: 1.18rem; }
  .progress-row { padding: .95rem 1.05rem; gap: .8rem; }
  .progress-icon { width: 36px; height: 36px; font-size: 1rem; }
  .feature-grid { grid-template-columns: 1fr; }
  .faq-item > summary { padding: .85rem 2.3rem .85rem 1rem; font-size: .88rem; }
  .faq-item > summary::after { right: 1.1rem; }
  .faq-answer { padding: 0 1rem .95rem; }
}