/* ============================================================
   擎天科创团队 · 极简风主页
   设计规范来源：github.com/anthropics/skills · frontend-design
   配色全部提取自团队 logo：藏青 #002040 / 鎏金 #a08040
   ============================================================ */

:root {
  --navy: #002040;   /* 擎天藏青（logo 主色）：标题、按钮、页脚 */
  --gold: #a08040;   /* 鎏金（logo 辅色）：唯一强调色，仅两处 */
  --ink: #223244;    /* 正文墨蓝 */
  --mist: #5d6b7a;   /* 次级雾灰 */
  --cloud: #f6f7f8;  /* 冷云白背景 */
  --line: #e3e6e9;   /* 细线 */
  --serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", STSong, SimSun, serif;
  --sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--cloud);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 顶部导航 ---------- */

.top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 0;
}

.wordmark {
  font-family: var(--serif);
  font-size: 19px;
  letter-spacing: 0.08em;
  color: var(--navy);
  text-decoration: none;
}

.join-link {
  font-size: 14px;
  color: var(--navy);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.join-link:hover { border-bottom-color: var(--gold); }

.join-link:focus-visible,
.cta:focus-visible,
.foot a:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- Hero：页面唯一的视觉重心 ---------- */

.hero {
  padding: 72px 0 96px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.logo-disc {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 1px 2px rgba(0, 32, 64, 0.08), 0 10px 36px rgba(0, 32, 64, 0.12);
}

.name {
  font-family: var(--serif);
  font-weight: 400;
  font-size: clamp(38px, 7vw, 58px);
  letter-spacing: 0.06em;
  color: var(--navy);
  margin: 40px 0 0;
}

.tagline {
  color: var(--mist);
  font-size: 17px;
  margin: 14px 0 0;
}

.divider {
  width: 56px;
  height: 2px;
  background: var(--gold);
  border: 0;
  margin: 30px 0 0;
}

.cta {
  margin-top: 40px;
  display: inline-block;
  background: var(--navy);
  color: #ffffff;
  text-decoration: none;
  font-size: 16px;
  letter-spacing: 0.14em;
  padding: 14px 46px;
  border-radius: 999px;
  transition: background 0.2s ease;
}

.cta:hover { background: #0a3a6e; }

/* ---------- 正文小节 ---------- */

.section { padding: 64px 0 8px; }

.section h2 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 21px;
  letter-spacing: 0.04em;
  color: var(--navy);
  margin: 0 0 18px;
}

.lede {
  max-width: 62ch;
  margin: 0;
  font-size: 16.5px;
}

.work {
  padding: 64px 0 96px;
}

.work-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 44px;
  border-top: 1px solid var(--line);
  padding-top: 36px;
  margin: 0;
}

.work-grid h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 17px;
  color: var(--navy);
  margin: 0 0 8px;
}

.work-grid p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 页脚 ---------- */

.foot {
  background: var(--navy);
  color: #c9d4df;
  padding: 36px 0;
  font-size: 13.5px;
}

.foot .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.foot a {
  color: #ffffff;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
  padding-bottom: 1px;
}

.foot a:hover { border-bottom-color: var(--gold); }

/* ---------- 入场动效：全页仅此一处编排 ---------- */

@keyframes rise {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: none; }
}

.hero > * { animation: rise 0.7s ease both; }
.hero > *:nth-child(1) { animation-delay: 0.05s; }
.hero > *:nth-child(2) { animation-delay: 0.18s; }
.hero > *:nth-child(3) { animation-delay: 0.30s; }
.hero > *:nth-child(4) { animation-delay: 0.42s; }
.hero > *:nth-child(5) { animation-delay: 0.54s; }

@media (prefers-reduced-motion: reduce) {
  .hero > * { animation: none; }
}

/* ---------- 身份选项列表（加入我们） ---------- */

.options-wrap { padding-bottom: 96px; }

.option-list {
  display: block;
  border-top: 1px solid var(--line);
  margin-top: 8px;
}

.option {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 26px 4px;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}

.option-name {
  font-family: var(--serif);
  font-size: 21px;
  letter-spacing: 0.04em;
  color: var(--navy);
  width: fit-content;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease;
}

.option:hover .option-name { border-bottom-color: var(--gold); }

.option:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: -2px;
}

.option-desc {
  font-size: 14.5px;
  color: var(--mist);
}

/* ---------- 移动端 ---------- */

@media (max-width: 640px) {
  .hero { padding: 56px 0 72px; }
  .logo-disc { width: 120px; height: 120px; }
  .work-grid { grid-template-columns: 1fr; gap: 30px; }
  .section, .work { padding-top: 48px; }
  .work { padding-bottom: 72px; }
  .options-wrap { padding-bottom: 72px; }
  .option { padding: 20px 2px; }
}