/* ========== 设计令牌 ========== */
:root{
  --ink:#1f3d2b;          /* 墨绿 · 主色 */
  --ink-2:#2d5a3f;
  --paper:#f5f1e8;        /* 米白 · 底 */
  --paper-2:#efe9da;
  --line:#d9d2bf;
  --accent:#c0392b;       /* 朱红 · 强调（三区三线） */
  --accent-2:#e74c3c;
  --mute:#6b7280;
  --text:#26322a;
  --maxw:1120px;
  --shadow:0 1px 0 rgba(31,61,43,.06), 0 12px 32px -18px rgba(31,61,43,.25);
  --serif:"Songti SC","SimSun",serif;
}

/* ========== Reset ========== */
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  font-family:"PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  color:var(--text);
  background:var(--paper);
  line-height:1.7;
  font-size:16px;
  /* 规划图纸感的细网格 */
  background-image:
    linear-gradient(rgba(31,61,43,.035) 1px,transparent 1px),
    linear-gradient(90deg,rgba(31,61,43,.035) 1px,transparent 1px);
  background-size:32px 32px;
}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}

/* ========== 顶部导航 ========== */
.topbar{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;gap:24px;
  padding:14px 32px;
  background:rgba(245,241,232,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar__brand{font-weight:800;font-size:18px;color:var(--ink);letter-spacing:.5px}
.topbar__brand-dot{color:var(--accent)}
.topbar__nav{display:flex;gap:22px;margin-left:auto}
.topbar__nav a{font-size:14px;color:var(--mute);transition:color .2s}
.topbar__nav a:hover{color:var(--ink)}
.topbar__cta{
  font-size:13px;padding:8px 16px;
  background:var(--ink);color:var(--paper);border-radius:2px;
  transition:background .2s;
}
.topbar__cta:hover{background:var(--accent)}
.topbar--scrolled{box-shadow:0 2px 14px rgba(31,61,43,.1)}

/* ========== 滚动入场 ========== */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease}
.reveal.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.reveal{opacity:1!important;transform:none!important;transition:none}}

/* ========== Hero ========== */
.hero{
  max-width:var(--maxw);margin:0 auto;
  padding:96px 32px 72px;
  position:relative;
}
.hero__kicker{
  color:var(--accent);font-weight:600;font-size:14px;letter-spacing:2px;
  margin-bottom:22px;text-transform:uppercase;
}
.hero__kicker::before{content:"";display:inline-block;width:36px;height:2px;background:var(--accent);vertical-align:middle;margin-right:12px}
.hero__title{
  font-size:clamp(30px,5vw,54px);
  line-height:1.25;font-weight:800;color:var(--ink);
  margin-bottom:28px;letter-spacing:-.5px;
}
.hero__title strong{color:var(--accent);font-weight:800}
.hero__lead{
  max-width:680px;font-size:17px;color:#41524a;margin-bottom:32px;
}
.hero__tags{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:36px}
.hero__tags li{
  font-size:13px;padding:6px 14px;
  background:var(--paper-2);border:1px solid var(--line);
  border-radius:2px;color:var(--ink);font-weight:500;
}
.hero__meta{display:flex;flex-wrap:wrap;gap:24px;font-size:14px;color:var(--mute)}
.hero__scroll{position:absolute;right:32px;bottom:32px;font-size:12px;color:var(--mute);letter-spacing:2px;animation:bob 2s ease-in-out infinite}
@keyframes bob{0%,100%{transform:translateY(0)}50%{transform:translateY(6px)}}

/* ========== Block 通用 ========== */
.block{
  max-width:var(--maxw);margin:0 auto;
  padding:72px 32px;
  border-top:1px solid var(--line);
}
.block__head{margin-bottom:48px;display:grid;grid-template-columns:auto 1fr;gap:6px 20px;align-items:baseline}
.block__num{
  grid-row:span 2;
  font-size:13px;font-weight:700;color:var(--paper);
  background:var(--ink);padding:6px 10px;border-radius:2px;
  align-self:start;letter-spacing:1px;
}
.block__title{font-size:30px;font-weight:800;color:var(--ink);letter-spacing:-.3px}
.block__sub{grid-column:2;color:var(--mute);font-size:15px}

/* ========== 关于 ========== */
.about{display:grid;grid-template-columns:1.1fr .9fr;gap:56px}
.about__h{
  font-size:14px;color:var(--accent);font-weight:700;letter-spacing:2px;
  margin-bottom:22px;padding-bottom:10px;border-bottom:2px solid var(--ink);
}
.timeline{position:relative;padding-left:22px}
.timeline::before{content:"";position:absolute;left:5px;top:6px;bottom:6px;width:2px;background:var(--line)}
.timeline__item{position:relative;margin-bottom:30px}
.timeline__item::before{content:"";position:absolute;left:-22px;top:8px;width:12px;height:12px;border-radius:50%;background:var(--paper);border:2px solid var(--accent)}
.timeline__when{font-size:12px;color:var(--accent);font-weight:700;letter-spacing:1px;margin-bottom:4px}
.timeline__role{font-size:17px;font-weight:700;color:var(--ink)}
.timeline__org{font-size:14px;color:#41524a;margin:2px 0 6px}
.timeline__desc{font-size:14px;color:var(--mute)}
.offer li{font-size:14px;color:#41524a;margin-bottom:14px;padding-left:18px;position:relative}
.offer li::before{content:"";position:absolute;left:0;top:11px;width:8px;height:2px;background:var(--accent)}
.offer b{color:var(--ink)}
.about__stat{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:28px;padding-top:24px;border-top:1px dashed var(--line)}
.about__stat div{text-align:center}
.about__stat b{display:block;font-size:28px;color:var(--accent);font-weight:800;font-family:var(--serif)}
.about__stat span{font-size:12px;color:var(--mute)}

/* ========== 项目分组 ========== */
.group{margin-bottom:64px}
.group__title{
  display:flex;align-items:center;gap:14px;
  font-size:20px;font-weight:800;color:var(--ink);
  margin-bottom:24px;padding-bottom:12px;border-bottom:1px solid var(--line);
}
.group__tag{
  display:inline-flex;align-items:center;justify-content:center;
  width:28px;height:28px;background:var(--ink);color:var(--paper);
  font-size:14px;border-radius:2px;
}
.group__org{margin-left:auto;font-size:13px;color:var(--mute);font-weight:500}

/* 详展 */
.feature{background:#fff;border:1px solid var(--line);border-left:4px solid var(--accent);padding:28px 30px;margin-bottom:28px;box-shadow:var(--shadow)}
.feature__head{margin-bottom:18px;padding-bottom:16px;border-bottom:1px dashed var(--line)}
.feature__title{font-size:21px;font-weight:800;color:var(--ink);line-height:1.4}
.feature__meta{font-size:13px;color:var(--mute);margin-top:6px}
.feature__abstract p{font-size:15px;color:#41524a;margin-bottom:12px}
.feature__role{font-size:14px;color:var(--ink);background:var(--paper-2);padding:10px 14px;border-radius:2px;border-left:3px solid var(--ink)}
.feature__figures{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:22px 0}
.feature__figures--3{grid-template-columns:repeat(3,1fr)}
.fig{position:relative}
.fig img{width:100%;border:1px solid var(--line);background:var(--paper-2);aspect-ratio:16/10;object-fit:cover;transition:transform .3s}
.fig:hover img{transform:scale(1.02)}
.fig figcaption{font-size:12px;color:var(--mute);margin-top:6px;line-height:1.4}
.feature__data{display:grid;grid-template-columns:repeat(4,1fr);gap:16px;margin-top:22px;padding-top:20px;border-top:2px solid var(--ink)}
.feature__data div{}
.feature__data b{display:block;font-size:24px;color:var(--accent);font-weight:800;font-family:var(--serif)}
.feature__data span{font-size:12px;color:var(--mute);line-height:1.4}

/* 卡片条目 */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.card{background:#fff;border:1px solid var(--line);padding:18px 20px;transition:border-color .2s,transform .2s}
.card:hover{border-color:var(--accent);transform:translateY(-2px)}
.card h5{font-size:15px;font-weight:700;color:var(--ink);margin-bottom:8px}
.card p{font-size:13px;color:var(--mute);margin-bottom:10px}
.card__chip{font-size:11px;color:var(--accent);border:1px solid var(--accent);padding:2px 8px;border-radius:2px}

/* ========== 技术研发仓库卡 ========== */
.repo-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.repo{
  background:#fff;border:1px solid var(--line);padding:18px;
  display:flex;flex-direction:column;gap:8px;
  transition:border-color .2s,transform .2s,box-shadow .2s;
}
.repo:hover{border-color:var(--ink);transform:translateY(-3px);box-shadow:var(--shadow)}
.repo__top{display:flex;justify-content:space-between;align-items:center;font-size:12px}
.repo__lang{font-weight:700;color:var(--ink);padding:2px 8px;background:var(--paper-2);border-radius:10px}
.repo__star{color:var(--accent);font-weight:600}
.repo h5{font-size:15px;font-weight:700;color:var(--ink);line-height:1.35}
.repo p{font-size:12.5px;color:var(--mute);line-height:1.55}

/* ========== 研究成果 ========== */
.research{display:grid;grid-template-columns:1fr 1fr;gap:48px}
.research__h{font-size:15px;color:var(--ink);font-weight:800;margin-bottom:18px;padding-left:12px;border-left:3px solid var(--accent)}
.research__h--mt{margin-top:36px}
.list li{padding:14px 0;border-bottom:1px dashed var(--line)}
.list__title{font-size:15px;font-weight:600;color:var(--text);line-height:1.45}
.list__meta{font-size:12.5px;color:var(--mute);margin-top:4px}
.list__sub{font-size:12px;color:var(--mute);margin-top:2px}
.hl{color:var(--accent);font-weight:700}

/* ========== 技能 ========== */
.skills{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.skill{background:#fff;border:1px solid var(--line);padding:22px 24px}
.skill h4{font-size:16px;font-weight:800;color:var(--ink);margin-bottom:10px;display:flex;align-items:center;gap:8px}
.skill h4::before{content:"";width:4px;height:16px;background:var(--accent)}
.skill p{font-size:14px;color:#41524a;line-height:1.8}

/* ========== Footer ========== */
.foot{background:var(--ink);color:var(--paper);margin-top:48px}
.foot__inner{max-width:var(--maxw);margin:0 auto;padding:56px 32px 40px;display:grid;grid-template-columns:1.4fr 1fr;gap:40px;align-items:center}
.foot__main h3{font-size:24px;font-weight:800;margin-bottom:8px}
.foot__main p{color:rgba(245,241,232,.7);font-size:14px}
.foot__contact li{display:flex;gap:14px;padding:8px 0;font-size:14px;border-bottom:1px solid rgba(245,241,232,.15)}
.foot__contact span{color:rgba(245,241,232,.5);width:60px;flex-shrink:0}
.foot__contact a{color:var(--paper);font-weight:600}
.foot__contact a:hover{color:var(--accent-2)}
.foot__copy{text-align:center;padding:18px;font-size:12px;color:rgba(245,241,232,.4);border-top:1px solid rgba(245,241,232,.1)}

/* ========== 响应式 ========== */
@media (max-width:900px){
  .topbar{padding:12px 18px;gap:12px}
  .topbar__nav{display:none}
  .hero{padding:56px 18px 48px}
  .block{padding:48px 18px}
  .block__head{grid-template-columns:auto 1fr}
  .about,.research{grid-template-columns:1fr;gap:32px}
  .feature__figures,.feature__figures--3{grid-template-columns:repeat(2,1fr)}
  .feature__data{grid-template-columns:repeat(2,1fr)}
  .cards{grid-template-columns:repeat(2,1fr)}
  .repo-grid{grid-template-columns:repeat(2,1fr)}
  .skills{grid-template-columns:1fr}
  .about__stat{grid-template-columns:repeat(4,1fr)}
  .foot__inner{grid-template-columns:1fr;padding:40px 18px}
}
@media (max-width:560px){
  .feature__figures,.feature__figures--3,.cards,.repo-grid{grid-template-columns:1fr}
  .feature{padding:20px}
  .hero__meta{gap:14px}
}

/* ========== 打印 / PDF ========== */
@media print{
  body{background:#fff;background-image:none;font-size:11pt}
  .reveal{opacity:1!important;transform:none!important}
  .topbar,.hero__scroll{display:none}
  .hero{padding:24px 0 32px}
  .hero__title{font-size:24pt}
  .block{padding:24px 0;border-top:2px solid #333;page-break-inside:avoid}
  .group{page-break-inside:avoid;margin-bottom:28px}
  .feature,.card,.repo,.skill{box-shadow:none;break-inside:avoid}
  .feature{border-left-width:3px}
  .fig,.feature__figures,.feature__figures--3{break-inside:avoid}
  .fig img{object-fit:contain}
  a{color:#000}
  .foot{background:#fff;color:#000;border-top:2px solid #333}
  .foot__main h3,.foot__main p,.foot__contact a,.foot__contact span,.foot__copy{color:#000}
  .foot__contact li{border-color:#ccc}
}