/* ==========================================================================
   Kim Hoi Zhang Group — 课题组主页样式
   文件结构：
     1. 变量与基础设置
     2. 通用排版与容器
     3. 顶部导航
     4. 首屏 Hero
     5. 关于课题组
     6. 研究方向
     7. 团队成员
     8. 论文成果
     9. 组内动态
    10. 加入我们
    11. 联系方式
    12. 页脚与返回顶部
    13. 入场动画
    14. 响应式（平板 / 手机）
   ========================================================================== */

/* 1. 变量与基础设置 ------------------------------------------------------- */
:root {
  --ink: #0d1e29;
  --ink-soft: #1c3542;
  --ink-mute: #40596a;
  --text: #23353f;
  --muted: #61727d;
  --line: #e3ded2;
  --line-soft: #ece7dc;
  --paper: #faf8f3;
  --paper-2: #f3efe5;
  --white: #fffefb;
  --accent: #0e7c78;
  --accent-soft: #d8ecea;
  --accent-deep: #0a5f5d;
  --gold: #b1832f;
  --gold-soft: #e8dcc2;

  --font: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Noto Sans SC",
    "Source Han Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  --font-serif: Georgia, "Times New Roman", "Songti SC", "SimSun", serif;

  --wrap: 1120px;
  --gutter: 24px;
  --header-h: 68px;
  --radius: 16px;
  --radius-lg: 26px;
  --shadow-sm: 0 1px 2px rgba(13, 30, 41, 0.05), 0 10px 26px -18px rgba(13, 30, 41, 0.35);
  --shadow-md: 0 2px 4px rgba(13, 30, 41, 0.05), 0 22px 48px -26px rgba(13, 30, 41, 0.45);
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

/* 让 JS 用 hidden 属性控制显示/隐藏时一定生效（否则会被 display:grid 覆盖） */
[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.85;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--accent-deep);
  text-decoration: none;
  transition: color 0.2s var(--ease);
}

a:hover {
  color: var(--accent);
}

::selection {
  background: var(--accent-soft);
  color: var(--ink);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 10px 16px;
  background: var(--ink);
  color: #fff;
  border-radius: 8px;
  transform: translateY(-200%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
  color: #fff;
}

/* 2. 通用排版与容器 ------------------------------------------------------- */
.wrap {
  width: min(100% - (var(--gutter) * 2), var(--wrap));
  margin-inline: auto;
}

.section {
  padding-block: clamp(64px, 9vw, 108px);
}

.section--tight {
  padding-block: clamp(48px, 6vw, 72px);
}

.section--alt {
  background: var(--paper-2);
  border-block: 1px solid var(--line-soft);
}

.section-head {
  max-width: 760px;
  margin-bottom: clamp(32px, 4vw, 52px);
}

.kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 18px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--ink-mute);
  text-transform: uppercase;
}

.kicker span {
  color: var(--gold);
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  letter-spacing: 0.08em;
}

.kicker::after {
  content: "";
  flex: 1;
  max-width: 64px;
  height: 1px;
  background: var(--gold-soft);
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

h2 {
  font-size: clamp(1.6rem, 2.6vw, 2.3rem);
  line-height: 1.35;
}

h3 {
  font-size: 1.0625rem;
  line-height: 1.55;
}

p {
  margin: 0 0 1em;
}

p:last-child {
  margin-bottom: 0;
}

.lead {
  font-size: clamp(1.0625rem, 1.4vw, 1.1875rem);
  line-height: 1.95;
  color: var(--ink-mute);
}

.muted {
  color: var(--muted);
}

/* 不让中英文混排的名字被拆到两行 */
.nb {
  white-space: nowrap;
}

.small {
  font-size: 0.875rem;
  line-height: 1.8;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 24px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;
  transition: transform 0.2s var(--ease), background-color 0.2s var(--ease),
    border-color 0.2s var(--ease), color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn svg {
  width: 16px;
  height: 16px;
  flex: none;
}

.btn--solid {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 10px 22px -14px rgba(13, 30, 41, 0.9);
}

.btn--solid:hover {
  background: var(--accent-deep);
  color: #fff;
}

.btn--light {
  background: var(--paper);
  color: var(--ink);
}

.btn--light:hover {
  background: #fff;
  color: var(--accent-deep);
}

.btn--ghost {
  border-color: var(--line);
  background: transparent;
  color: var(--ink);
}

.btn--ghost:hover {
  border-color: var(--ink);
  background: var(--white);
}

.btn--on-dark {
  border-color: rgba(255, 255, 255, 0.32);
  background: transparent;
  color: #f2efe6;
}

.btn--on-dark:hover {
  border-color: rgba(255, 255, 255, 0.75);
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
}

.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink-mute);
  white-space: nowrap;
}

.tag--accent {
  border-color: transparent;
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.tag--muted {
  border-style: dashed;
  background: transparent;
  color: var(--muted);
}

/* 占位文字：提醒你需要替换成真实内容 */
.todo {
  border-bottom: 1px dashed currentColor;
  color: var(--muted);
  font-style: normal;
  cursor: help;
}

/* 3. 顶部导航 ------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(250, 248, 243, 0.82);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.site-header.is-scrolled {
  background: rgba(250, 248, 243, 0.95);
  border-bottom-color: var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  min-width: 0;
}

.brand:hover {
  color: var(--ink);
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  flex: none;
  border-radius: 11px;
  background: var(--ink);
  color: #7fd8d1;
}

.brand-mark svg {
  width: 24px;
  height: 24px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
  min-width: 0;
}

.brand-text strong {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-text small {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav a {
  display: block;
  padding: 8px 13px;
  border-radius: 999px;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--ink-mute);
  letter-spacing: 0.03em;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}

.nav a:hover {
  background: var(--paper-2);
  color: var(--ink);
}

.nav a[aria-current="true"],
.nav a[aria-current="page"] {
  background: var(--ink);
  color: #fff;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
}

.nav-toggle svg {
  width: 20px;
  height: 20px;
}

.nav-toggle .icon-close {
  display: none;
}

.nav-toggle[aria-expanded="true"] .icon-close {
  display: block;
}

.nav-toggle[aria-expanded="true"] .icon-open {
  display: none;
}

/* 3.5 语言切换按钮 -------------------------------------------------------- */
.header-end {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  min-width: 52px;
  padding: 0 14px;
  flex: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--ink-mute);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease),
    background-color 0.2s var(--ease);
}

.lang-switch:hover {
  color: var(--accent-deep);
  border-color: #bcd9d6;
  background: var(--accent-soft);
}

/* 按钮上是中文时（英文页），去掉宽字距 */
.lang-switch--zh {
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
}

/* 4. 首屏 Hero ----------------------------------------------------------- */
.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  width: min(100% - (var(--gutter) * 2), 1240px);
  margin: 4px auto 0;
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 140% at 84% 8%, rgba(38, 116, 112, 0.55) 0%, transparent 58%),
    linear-gradient(155deg, #0a1a24 0%, #102b37 52%, #0c3437 100%);
  color: #eef3f2;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -6%;
  z-index: -2;
  background: url("../img/network.svg") center / cover no-repeat;
  opacity: 0.5;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(94deg, rgba(8, 20, 28, 0.94) 0%, rgba(8, 20, 28, 0.78) 44%, rgba(8, 20, 28, 0.2) 100%),
    radial-gradient(100% 100% at 100% 100%, rgba(4, 12, 16, 0.6) 0%, transparent 60%);
}

.hero-inner {
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: min(78vh, 720px);
  padding: clamp(48px, 7vw, 88px) clamp(24px, 5vw, 72px);
}

.hero-eyebrow {
  display: inline-flex;
  align-items: flex-start;
  gap: 10px;
  margin: 0 0 22px;
  font-size: 0.8125rem;
  font-weight: 700;
  line-height: 1.6;
  letter-spacing: 0.16em;
  color: #9fd6d1;
  text-transform: uppercase;
}

.hero-eyebrow::before {
  content: "";
  flex: none;
  width: 26px;
  height: 1px;
  margin-top: 0.8em;
  background: currentColor;
  opacity: 0.8;
}

.hero h1 {
  max-width: 15ch;
  margin: 0;
  color: #fdfcf8;
  font-size: clamp(2.35rem, 5.4vw, 4.1rem);
  line-height: 1.1;
  letter-spacing: -0.015em;
}

.hero-name {
  display: block;
  font-family: var(--font-serif);
  font-weight: 700;
  letter-spacing: -0.005em;
}

.hero-sub {
  display: block;
  max-width: 22ch;
  margin-top: 16px;
  font-size: 0.4em;
  font-weight: 500;
  line-height: 1.55;
  letter-spacing: 0.02em;
  color: #9fd8d3;
}

/* 中文页：大标题是汉字，改用黑体并收一点字距 */
.hero-name--zh {
  font-family: var(--font);
  font-weight: 800;
  letter-spacing: 0.06em;
}

/* 汉字姓名下面那行拉丁名（或英文页的主标题下方的中文名） */
.hero-latin {
  display: block;
  margin-top: 14px;
  font-family: var(--font-serif);
  font-size: clamp(0.8125rem, 1.3vw, 1rem);
  font-weight: 600;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: rgba(238, 243, 242, 0.52);
}

.hero-lead {
  max-width: 46ch;
  margin: 24px 0 0;
  font-size: clamp(1rem, 1.25vw, 1.125rem);
  line-height: 1.95;
  color: rgba(238, 243, 242, 0.82);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 22px;
  margin: clamp(36px, 6vw, 64px) 0 0;
  padding-top: 22px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: rgba(238, 243, 242, 0.62);
}

.hero-meta span {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.hero-meta span::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #6fc8c2;
}

/* 5. 关于课题组 ----------------------------------------------------------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(32px, 5vw, 72px);
  align-items: start;
}

.about-copy .lead {
  margin-bottom: 1.2em;
}

.about-copy p {
  color: var(--ink-mute);
}

.pullquote {
  margin: 28px 0 0;
  padding: 4px 0 4px 22px;
  border-left: 3px solid var(--gold);
  font-family: var(--font-serif);
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

.fact-list {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.fact {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 16px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

.fact-icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.fact-icon svg {
  width: 21px;
  height: 21px;
}

.fact h3 {
  margin: 0 0 2px;
  font-size: 0.9375rem;
}

.fact p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--muted);
}

/* 6. 研究方向 ------------------------------------------------------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.research-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.research-card:hover {
  transform: translateY(-4px);
  border-color: #cfd9d6;
  box-shadow: var(--shadow-md);
}

.research-card .num {
  position: absolute;
  top: 22px;
  right: 26px;
  font-family: var(--font-serif);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  color: #c9c2b0;
}

.research-icon {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: linear-gradient(150deg, var(--ink) 0%, #16414a 100%);
  color: #8fdcd5;
}

.research-icon svg {
  width: 23px;
  height: 23px;
}

.research-card h3 {
  margin: 0;
  font-size: 1.125rem;
}

.research-card .en {
  display: block;
  margin-top: 4px;
  font-family: var(--font-serif);
  font-size: 0.8125rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.research-card p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-mute);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  padding-top: 6px;
}

/* 7. 团队成员 ------------------------------------------------------------- */
.pi-grid {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
  margin-bottom: clamp(40px, 6vw, 64px);
}

.portrait {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background:
    radial-gradient(120% 120% at 20% 0%, #1d4854 0%, transparent 60%),
    linear-gradient(160deg, #0e2430 0%, #123740 100%);
  aspect-ratio: 4 / 5;
  box-shadow: var(--shadow-md);
}

.portrait::before {
  content: attr(data-label);
  position: absolute;
  left: 14px;
  bottom: 14px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.75);
}

.portrait img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 放了真实照片以后，那个"照片待补充"的小标签就不再显示 */
.portrait:has(img)::before {
  display: none;
}

.portrait .monogram {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--font-serif);
  font-size: clamp(3rem, 6vw, 4.5rem);
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.82);
}

.pi-name {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  margin: 0;
  font-size: clamp(1.5rem, 2.4vw, 2rem);
}

.pi-name small {
  font-family: var(--font);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--gold);
  text-transform: uppercase;
}

/* 中文页的 PI 姓名用黑体；拉丁名单独一行，衬线小字 */
.pi-name--zh {
  font-family: var(--font);
  letter-spacing: 0.04em;
}

.pi-latin {
  margin: 8px 0 0;
  font-family: var(--font-serif);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--muted);
}

.pi-role {
  margin: 6px 0 20px;
  font-size: 0.9375rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}

.pi-grid p {
  color: var(--ink-mute);
}

.member-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.member {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 22px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: rgba(255, 253, 248, 0.7);
  transition: border-color 0.25s var(--ease), background-color 0.25s var(--ease);
}

.member:hover {
  border-color: var(--accent);
  background: var(--white);
}

.member h3 {
  margin: 0;
  font-size: 0.9375rem;
}

.member p {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--muted);
}

.member .tag {
  align-self: flex-start;
}

/* 8. 论文成果 ------------------------------------------------------------- */
.pub-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 22px;
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter {
  padding: 7px 15px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--ink-mute);
  cursor: pointer;
  transition: all 0.2s var(--ease);
}

.filter:hover {
  border-color: var(--ink);
  color: var(--ink);
}

.filter[aria-pressed="true"] {
  border-color: var(--ink);
  background: var(--ink);
  color: #fff;
}

.pub-list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.pub {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 20px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.pub-year {
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  padding-top: 2px;
}

.pub-title {
  margin: 0 0 6px;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.6;
  color: var(--ink);
}

.pub-authors {
  margin: 0 0 4px;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--muted);
}

.pub-authors b {
  color: var(--ink-soft);
  font-weight: 700;
}

.pub-journal {
  font-family: var(--font-serif);
  font-size: 0.875rem;
  font-style: italic;
  color: var(--ink-mute);
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 8px;
  font-size: 0.8125rem;
  font-weight: 700;
}

.empty-state {
  display: grid;
  gap: 10px;
  place-items: center;
  padding: clamp(36px, 6vw, 60px) 24px;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  background: var(--white);
  text-align: center;
}

/* 论文列表下方那行"自动同步自 ORCID" */
.pub-source {
  margin: 20px 0 0;
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.pub-source a {
  font-weight: 700;
}

.empty-state svg {
  width: 30px;
  height: 30px;
  color: var(--accent);
  opacity: 0.9;
}

.empty-state p {
  max-width: 44ch;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--muted);
}

/* 9. 组内动态 ------------------------------------------------------------- */
.timeline {
  position: relative;
  display: grid;
  gap: 4px;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(var(--gold-soft), var(--line));
}

.timeline li {
  position: relative;
  padding: 0 0 26px;
}

.timeline li::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 9px;
  width: 11px;
  height: 11px;
  border: 2px solid var(--paper-2);
  border-radius: 50%;
  background: var(--accent);
}

.timeline li.is-latest::before {
  background: var(--gold);
}

.news-date {
  display: block;
  font-family: var(--font-serif);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.news-title {
  margin: 2px 0 4px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink);
}

.timeline p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-mute);
}

/* 10. 加入我们 ------------------------------------------------------------ */
.join-panel {
  position: relative;
  overflow: hidden;
  padding: clamp(32px, 5vw, 60px);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(110% 130% at 88% 0%, rgba(41, 122, 117, 0.5) 0%, transparent 55%),
    linear-gradient(150deg, #0a1a24 0%, #123039 100%);
  color: #eaf1f0;
}

.join-panel .kicker {
  color: rgba(234, 241, 240, 0.7);
}

.join-panel .kicker span {
  color: #d8b878;
}

.join-panel .kicker::after {
  background: rgba(216, 184, 120, 0.4);
}

.join-panel h2 {
  max-width: 24ch;
  color: #fdfcf8;
}

.join-panel p {
  max-width: 52ch;
  color: rgba(234, 241, 240, 0.8);
}

.join-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: clamp(28px, 5vw, 60px);
  align-items: start;
  margin-top: 26px;
}

.steps {
  display: grid;
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 14px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.steps li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.steps li::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  font-family: var(--font-serif);
  font-size: 0.875rem;
  color: #d8b878;
  padding-top: 2px;
}

.steps h3 {
  margin: 0 0 2px;
  color: #f4f7f6;
  font-size: 0.9375rem;
}

.steps p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.8;
  color: rgba(234, 241, 240, 0.72);
}

.join-note {
  padding: 22px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.05);
}

.join-note h3 {
  margin: 0 0 10px;
  color: #fff;
  font-size: 0.9375rem;
}

.join-note ul {
  margin: 0;
  padding-left: 18px;
  font-size: 0.875rem;
  line-height: 1.9;
  color: rgba(234, 241, 240, 0.78);
}

.join-note li::marker {
  color: #6fc8c2;
}

/* 11. 联系方式 ------------------------------------------------------------ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: clamp(28px, 5vw, 64px);
  align-items: start;
}

.contact-list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.contact-list li {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.contact-list dt,
.contact-label {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.contact-value {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--ink);
}

.contact-value a {
  border-bottom: 1px solid var(--accent-soft);
}

.contact-card {
  padding: clamp(24px, 3vw, 32px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  box-shadow: var(--shadow-sm);
}

.contact-card h3 {
  margin: 0 0 12px;
  font-size: 1rem;
}

.contact-card p {
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--ink-mute);
}

.contact-card .btn {
  margin-top: 18px;
}

/* 12. 页脚与返回顶部 ------------------------------------------------------ */
.site-footer {
  padding: 44px 0 34px;
  border-top: 1px solid var(--line);
  background: var(--paper-2);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px 32px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand .brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
}

.footer-brand .brand-mark svg {
  width: 21px;
  height: 21px;
}

.footer-brand strong {
  display: block;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  color: var(--ink);
}

.footer-brand small {
  display: block;
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.8125rem;
}

.footer-links a {
  color: var(--ink-mute);
}

.footer-links a:hover {
  color: var(--accent-deep);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: 26px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-size: 0.75rem;
  letter-spacing: 0.03em;
  color: var(--muted);
}

.to-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 90;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--white);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.25s var(--ease), transform 0.25s var(--ease),
    visibility 0.25s var(--ease), background-color 0.2s var(--ease);
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover {
  background: var(--ink);
  color: #fff;
}

.to-top svg {
  width: 18px;
  height: 18px;
}

/* 13. 入场动画 ------------------------------------------------------------ */
/* 只有脚本正常运行时才启用"先隐藏、滚动到再淡入"，
   这样万一 main.js 没加载成功，页面内容也不会消失。 */
.js .reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.js .reveal.is-in {
  opacity: 1;
  transform: none;
}

.reveal[data-delay="1"] { transition-delay: 0.08s; }
.reveal[data-delay="2"] { transition-delay: 0.16s; }
.reveal[data-delay="3"] { transition-delay: 0.24s; }
.reveal[data-delay="4"] { transition-delay: 0.32s; }

/* 14. 英文页排版微调 ------------------------------------------------------ */
/* 英文页（en.html）在 <html lang="en"> 下，这里把中文字体栈换掉，
   行高、字距、行宽也按拉丁字母的习惯微调，其余样式与中文页完全共用。 */
html[lang="en"] {
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, "Microsoft YaHei", sans-serif;
}

html[lang="en"] body {
  line-height: 1.72;
  letter-spacing: 0;
}

html[lang="en"] h1,
html[lang="en"] h2,
html[lang="en"] h3 {
  letter-spacing: -0.012em;
}

html[lang="en"] .hero h1 {
  max-width: 20ch;
  letter-spacing: -0.02em;
}

html[lang="en"] .hero-sub {
  max-width: 34ch;
  font-size: 0.32em;
  letter-spacing: 0.01em;
}

html[lang="en"] .hero-lead {
  max-width: 54ch;
  line-height: 1.8;
}

html[lang="en"] .lead {
  line-height: 1.8;
}

html[lang="en"] .hero-eyebrow {
  letter-spacing: 0.12em;
}

html[lang="en"] .brand-text strong {
  letter-spacing: 0;
}

/* 英文一行能放的字更多，给新闻和正文设一个更舒服的行宽 */
html[lang="en"] .timeline p {
  max-width: 68ch;
}

html[lang="en"] .about-copy p {
  max-width: 74ch;
}

/* 15. 多页站点：页头、入口卡、成员分组 ------------------------------------ */

/* 子页面是从导航点进来的，顶部留白比首页小一点 */
main[data-page] > section.section:first-child {
  padding-top: clamp(44px, 6vw, 78px);
}

/* 每个独立页面的页头用 h1 */
.page-head {
  max-width: 820px;
  margin-bottom: clamp(30px, 4vw, 48px);
}

.page-head h1 {
  margin: 0;
  font-size: clamp(2rem, 4.4vw, 3.05rem);
  line-height: 1.16;
  letter-spacing: -0.01em;
}

.page-head .lead {
  margin: 18px 0 0;
}

/* 首页的三张入口卡 */
.entry-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.entry-card {
  display: flex;
  flex-direction: column;
  gap: 13px;
  padding: clamp(22px, 3vw, 30px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  background: var(--white);
  box-shadow: var(--shadow-sm);
  color: inherit;
  text-decoration: none;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.entry-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-soft);
  box-shadow: var(--shadow-md);
}

.entry-icon {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 13px;
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.entry-icon svg {
  width: 24px;
  height: 24px;
}

.entry-card h3 {
  margin: 4px 0 0;
  font-size: 1.125rem;
}

.entry-card p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--muted);
}

.entry-more {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: auto;
  padding-top: 8px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent-deep);
}

.entry-arrow {
  width: 16px;
  height: 16px;
  flex: none;
  transition: transform 0.3s var(--ease);
}

.entry-card:hover .entry-arrow,
.more-link a:hover .entry-arrow,
.btn:hover .btn-arrow {
  transform: translateX(4px);
}

.btn-arrow {
  width: 16px;
  height: 16px;
  flex: none;
  transition: transform 0.3s var(--ease);
}

.more-link {
  margin: 30px 0 0;
}

.more-link a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--accent-deep);
}

/* 成员按身份分组 */
.member-group {
  margin-top: clamp(28px, 4vw, 44px);
}

.member-group-title {
  margin: 0 0 14px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-mute);
}

.member-grid--auto {
  grid-template-columns: repeat(auto-fill, minmax(238px, 1fr));
}

.member-mail {
  margin: 0;
  font-size: 0.8125rem;
}

.member-mail a {
  color: var(--accent-deep);
  word-break: break-all;
}

/* 首页底部的联系条 */
.section--slim {
  padding-block: clamp(34px, 5vw, 52px);
}

.contact-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.contact-bar h3 {
  margin: 0 0 6px;
  font-size: 1.125rem;
}

.contact-bar p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--muted);
}

/* 首页招聘面板的紧凑版 */
.join-panel--teaser p {
  max-width: 62ch;
}

@media (max-width: 860px) {
  .entry-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }
}

/* 16. 响应式 -------------------------------------------------------------- */
@media (max-width: 1000px) {
  .about-grid,
  .contact-grid,
  .join-grid {
    grid-template-columns: 1fr;
  }

  .pi-grid {
    grid-template-columns: 240px minmax(0, 1fr);
  }

  .member-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* 英文页的导航文字比中文长，中等宽度先把字号和留白收一点，避免挤到语言按钮 */
@media (max-width: 1080px) {
  html[lang="en"] .header-inner {
    gap: 12px;
  }

  html[lang="en"] .brand-text small {
    display: none;
  }

  html[lang="en"] .nav a {
    padding: 8px 9px;
    font-size: 0.8125rem;
    letter-spacing: 0;
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 62px;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .nav {
    position: fixed;
    inset: var(--header-h) 0 auto;
    padding: 10px var(--gutter) 22px;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 24px 40px -30px rgba(13, 30, 41, 0.6);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.22s var(--ease), transform 0.22s var(--ease),
      visibility 0.22s var(--ease);
  }

  .nav.is-open {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav ul {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .nav a {
    padding: 12px 14px;
    border-radius: 10px;
    font-size: 0.9375rem;
  }

  .hero {
    border-radius: 20px;
  }

  .hero-inner {
    min-height: auto;
    padding-block: 48px 40px;
  }

  .hero h1 {
    max-width: 100%;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .pi-grid {
    grid-template-columns: 1fr;
  }

  .portrait {
    max-width: 260px;
  }

  .member-grid {
    grid-template-columns: 1fr;
  }

  .pub {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .contact-list li {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  :root {
    --gutter: 18px;
  }

  .brand-text small {
    display: none;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .section {
    padding-block: 56px;
  }
}

/* 尊重系统的"减少动态效果"设置 */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* 打印 */
@media print {
  .site-header,
  .to-top,
  .nav-toggle,
  .hero-actions {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .hero,
  .join-panel {
    background: #fff !important;
    color: #000 !important;
    border: 1px solid #ccc;
  }

  .hero h1,
  .hero-lead,
  .join-panel h2,
  .join-panel p,
  .join-panel .kicker {
    color: #000 !important;
  }

  .section {
    padding-block: 24px;
    break-inside: avoid;
  }

  .js .reveal {
    opacity: 1 !important;
    transform: none !important;
  }
}