/* ============ reset ============ */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;-webkit-font-smoothing:antialiased}
h1,h2,h3,h4,h5,h6,p,ul,ol,figure,blockquote,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
img,svg,video{display:block;max-width:100%}
input,textarea,select{font:inherit}
[hidden]{display:none!important}
:focus-visible{outline:2px solid #FF6B35;outline-offset:2px;border-radius:2px}

/* ============ tokens ============ */
:root{
  --sea:#0B3B5C;
  --ink:#072A42;
  --orange:#FF6B35;
  --orange-press:#C9451A;
  --teal:#2EC4B6;
  --teal-deep:#1B7F78;
  --paper:#F7F4EE;
  --mist:#F2F5F7;
  --line:#D5DDE3;
  --graphite:#24333D;
  --white:#FFFFFF;
  --muted:#6B7C88;

  --font-display:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;

  --rail-w:72px;
  --bar-h:56px;
  --maxw:1180px;
  --shadow-1:0 1px 2px rgba(11,59,92,.06);
  --shadow-2:0 8px 24px rgba(11,59,92,.08);
  --ease:cubic-bezier(.22,.61,.36,1);
}

body{
  background:var(--paper);
  color:var(--graphite);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  padding-top:var(--bar-h);
}
@media (min-width:768px){
  body{padding-top:0;padding-left:var(--rail-w)}
}

/* ============ 中文排版 ============ */
h1,h2,h3,h4{font-family:var(--font-display);font-weight:900;color:var(--sea);line-height:1.14;letter-spacing:-.01em}
h1{font-size:clamp(30px,4.6vw,52px);line-height:1.12;max-width:20em}
h2{font-size:clamp(23px,3vw,36px);max-width:22em}
h3{font-size:clamp(17px,1.8vw,20px);line-height:1.35;max-width:26em}
h4{font-size:16px;line-height:1.4}
p{max-width:38em}
.mono{font-family:var(--font-mono);letter-spacing:.08em}

/* ============ 布局工具 ============ */
.container{width:100%;max-width:var(--maxw);margin:0 auto;padding:0 clamp(16px,4vw,40px)}
.section{padding:clamp(44px,6vw,88px) 0}
.section--ink{background:var(--sea);color:rgba(255,255,255,.82);border-top:1px solid var(--ink);border-bottom:1px solid var(--ink)}
.section--ink h2,.section--ink h3,.section--ink h4{color:var(--white)}
.section--ink .eyebrow{color:var(--teal)}
.section--ink .status{color:var(--teal);border-color:currentColor}
.section--mist{background:var(--mist);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.prose{max-width:34em}
.prose p{margin-bottom:1em}
.prose h2,.prose h3{margin:1.6em 0 .6em}
.prose ul{list-style:none;margin-bottom:1em}
.prose li{padding-left:1.1em;position:relative}
.prose li::before{content:"";position:absolute;left:0;top:.75em;width:8px;height:1px;background:var(--orange-press)}

.grid{display:grid;gap:clamp(16px,2.4vw,24px);grid-template-columns:1fr}
@media (min-width:720px){
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:1000px){
  .grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
  .grid--rail{grid-template-columns:8fr 4fr;align-items:start}
}

/* ============ 章节与标签 ============ */
.eyebrow{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;color:var(--orange-press);line-height:1.4}
.eyebrow::before{content:"";width:18px;height:1px;background:currentColor;flex:0 0 auto}
.chapter-num{font-family:var(--font-mono);font-weight:700;font-size:clamp(28px,4vw,44px);line-height:1;letter-spacing:.02em;color:var(--orange);display:block}

.status{display:inline-flex;align-items:center;gap:6px;font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;line-height:1.2;padding:4px 8px;border:1px solid currentColor;border-radius:2px;white-space:nowrap}
.status::before{content:"";width:6px;height:6px;border-radius:50%;background:currentColor;flex:0 0 auto}
.status--accepted{color:var(--sea)}
.status--progress{color:var(--orange-press)}
.status--replied{color:var(--teal-deep)}
.status--closed{color:var(--muted)}

/* ============ 按钮 ============ */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 22px;border:1px solid transparent;border-radius:3px;font-family:var(--font-body);font-weight:700;font-size:15px;line-height:1.2;letter-spacing:.02em;transition:transform .18s var(--ease),background-color .18s var(--ease),border-color .18s var(--ease),color .18s var(--ease),box-shadow .18s var(--ease)}
.btn--primary{background:var(--orange);color:var(--ink);border-color:var(--orange);box-shadow:var(--shadow-1)}
.btn--primary:hover{background:var(--orange-press);border-color:var(--orange-press);color:var(--white);transform:translateY(-2px);box-shadow:var(--shadow-2)}
.btn--ghost{background:transparent;color:var(--sea);border-color:var(--line)}
.btn--ghost:hover{border-color:var(--sea);background:var(--mist);transform:translateY(-2px)}
.btn--dark{background:var(--sea);color:var(--white);border-color:var(--sea)}
.btn--dark:hover{background:var(--ink);border-color:var(--ink);transform:translateY(-2px)}

/* ============ 卡片与图片容器 ============ */
.card{background:var(--white);border:1px solid var(--line);border-radius:4px;padding:clamp(16px,2.4vw,22px);box-shadow:var(--shadow-1);transition:transform .2s var(--ease),box-shadow .2s var(--ease),border-color .2s var(--ease)}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow-2);border-color:#C3CFD8}

.media-frame{position:relative;overflow:hidden;border:1px solid var(--line);border-radius:4px;background:var(--mist);box-shadow:var(--shadow-1);aspect-ratio:16/10}
.media-frame::before{content:"";position:absolute;top:0;left:0;right:0;height:2px;background:var(--teal-deep);z-index:1}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:4/5}
.media-frame__caption{position:absolute;left:0;bottom:0;right:0;padding:10px 12px;font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--white);background:linear-gradient(to top,rgba(7,42,66,.78),rgba(7,42,66,0))}

/* ============ 面包屑 ============ */
.breadcrumb{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:20px 0 0;font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--muted)}
.breadcrumb__link{color:var(--teal-deep);text-decoration:underline;text-underline-offset:3px}
.breadcrumb__link:hover{color:var(--orange-press)}
.breadcrumb__sep{color:var(--line)}

/* ============ 滚动显现 ============ */
[data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .4s var(--ease),transform .4s var(--ease);transition-delay:var(--reveal-delay,0ms)}
[data-reveal].is-visible{opacity:1;transform:none}

/* ============ HEADER ============ */
.skip-link{position:fixed;top:8px;left:8px;z-index:300;padding:10px 16px;background:var(--orange);color:var(--ink);font-weight:700;font-size:14px;border-radius:3px;transform:translateY(-200%);transition:transform .18s var(--ease)}
.skip-link:focus{transform:none}

.site-header{
  position:fixed;top:0;left:0;right:0;z-index:120;
  display:flex;align-items:center;gap:8px;
  height:var(--bar-h);padding:0 12px;
  background:var(--ink);color:var(--white);
  border-bottom:1px solid rgba(213,221,227,.16);
}

.rail-brand{display:flex;align-items:center;gap:10px;min-width:0}
.rail-brand__mark{display:grid;place-items:center;width:32px;height:32px;flex:0 0 auto;background:var(--orange);color:var(--ink);font-family:var(--font-display);font-weight:900;font-size:15px;border-radius:3px}
.rail-brand__text{display:flex;flex-direction:column;line-height:1.15;min-width:0}
.rail-brand__name{font-family:var(--font-display);font-weight:900;font-size:16px;color:var(--white);letter-spacing:.02em}
.rail-brand__sub{font-family:var(--font-mono);font-size:9px;letter-spacing:.12em;color:var(--teal)}

.nav-toggle{display:inline-flex;flex-direction:column;justify-content:center;gap:5px;width:40px;height:40px;padding:0 9px;margin-left:auto;border:1px solid rgba(255,255,255,.28);border-radius:3px;flex:0 0 auto}
.nav-toggle__bar{display:block;height:2px;width:100%;background:var(--white);transition:transform .25s var(--ease),opacity .2s var(--ease)}
.site-header[data-open] .nav-toggle__bar:nth-child(1){transform:translateY(7px) rotate(45deg)}
.site-header[data-open] .nav-toggle__bar:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle__bar:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

.nav-drawer{
  position:fixed;top:var(--bar-h);right:0;bottom:0;z-index:2;
  width:min(320px,86vw);
  display:flex;flex-direction:column;
  padding:4px 0 24px;
  background:var(--sea);
  border-left:1px solid rgba(255,255,255,.1);
  box-shadow:var(--shadow-2);
  overflow-y:auto;
  transform:translateX(100%);
  visibility:hidden;
  transition:transform .32s var(--ease),visibility .32s var(--ease);
}
.site-header[data-open] .nav-drawer{transform:none;visibility:visible}

.nav-scrim{position:fixed;top:var(--bar-h);left:0;right:0;bottom:0;z-index:1;background:rgba(7,42,66,.58);opacity:0;visibility:hidden;transition:opacity .3s var(--ease),visibility .3s var(--ease)}
.site-header[data-open] .nav-scrim{opacity:1;visibility:visible}

.site-nav{flex:1 1 auto}
.site-nav__list{display:block}
.site-nav__link{display:flex;align-items:center;gap:14px;padding:14px 20px;font-size:15px;letter-spacing:.04em;color:rgba(255,255,255,.82);border-bottom:1px solid rgba(255,255,255,.09);transition:background-color .18s var(--ease),color .18s var(--ease)}
.site-nav__num{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--teal);flex:0 0 auto}
.site-nav__text{font-size:15px}
.site-nav__link:hover{background:rgba(255,255,255,.07);color:var(--white)}
.site-nav__link[aria-current="page"]{background:var(--orange);color:var(--ink);font-weight:700}
.site-nav__link[aria-current="page"] .site-nav__num{color:var(--ink)}

.rail-actions{margin-top:auto;border-top:1px solid rgba(255,255,255,.12);display:flex;flex-direction:column}
.rail-search{display:block;width:100%;padding:13px 20px;text-align:left;font-size:14px;letter-spacing:.04em;color:rgba(255,255,255,.85);border-bottom:1px solid rgba(255,255,255,.09);transition:background-color .18s var(--ease),color .18s var(--ease)}
.rail-search:hover{background:rgba(255,255,255,.07);color:var(--white)}
.rail-cta{display:block;width:100%;padding:15px 20px;text-align:center;background:var(--orange);color:var(--ink);font-weight:700;font-size:15px;letter-spacing:.04em;transition:background-color .18s var(--ease),color .18s var(--ease)}
.rail-cta:hover{background:var(--orange-press);color:var(--white)}

.rail-progress{position:fixed;top:var(--bar-h);left:0;right:0;height:2px;z-index:5;background:rgba(255,255,255,.1);pointer-events:none}
.rail-progress__bar{display:block;width:100%;height:100%;background:var(--orange);transform:scaleX(0);transform-origin:left center}

body.nav-open{overflow:hidden}

/* 检索层 */
.search-layer{position:fixed;inset:0;z-index:200;display:flex;justify-content:flex-end;background:rgba(7,42,66,.62)}
.search-layer__panel{width:min(520px,100%);max-height:100%;overflow-y:auto;display:flex;flex-direction:column;gap:16px;padding:20px clamp(16px,4vw,32px) 36px;background:var(--paper);border-left:1px solid var(--line);box-shadow:var(--shadow-2)}
.search-layer__head{display:flex;align-items:center;justify-content:space-between;gap:12px;padding-bottom:12px;border-bottom:1px solid var(--line)}
.search-layer__label{font-family:var(--font-mono);font-size:11px;letter-spacing:.2em;color:var(--sea);max-width:none}
.search-layer__close{padding:6px 12px;border:1px solid var(--line);border-radius:3px;font-size:12px;color:var(--sea);transition:background-color .18s var(--ease),border-color .18s var(--ease)}
.search-layer__close:hover{border-color:var(--sea);background:var(--mist)}
.search-layer__input{width:100%;padding:12px 14px;border:1px solid var(--line);border-radius:3px;background:var(--white);font-size:15px;color:var(--graphite)}
.search-layer__input:focus{outline:none;border-color:var(--sea);box-shadow:0 0 0 2px rgba(11,59,92,.14)}
.search-layer__results{display:flex;flex-direction:column}
.search-layer__item{border-bottom:1px solid var(--line)}
.search-layer__link{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:12px 2px;font-size:15px;color:var(--sea);transition:color .18s var(--ease),padding-left .18s var(--ease)}
.search-layer__link:hover{color:var(--orange-press);padding-left:6px}
.search-layer__name{font-weight:500}
.search-layer__meta{font-family:var(--font-mono);font-size:10px;letter-spacing:.14em;color:var(--teal-deep);flex:0 0 auto}
.search-layer__empty{padding:14px 2px;font-size:14px;color:var(--muted)}
.search-layer__hint{font-size:12px;line-height:1.6;color:var(--muted)}

/* ============ 桌面轨道 ============ */
@media (min-width:768px){
  .site-header{
    right:auto;bottom:0;height:auto;width:var(--rail-w);
    flex-direction:column;align-items:stretch;gap:0;
    padding:0;
    background:var(--sea);color:var(--white);
    border-bottom:0;border-right:1px solid var(--ink);
  }
  .skip-link{left:calc(var(--rail-w) + 12px)}

  .rail-brand{flex-direction:column;gap:8px;padding:14px 0 12px;border-bottom:1px solid rgba(255,255,255,.14)}
  .rail-brand__mark{width:38px;height:38px;font-size:17px}
  .rail-brand__text{align-items:center;gap:6px}
  .rail-brand__name{writing-mode:vertical-rl;font-size:15px;letter-spacing:.16em}
  .rail-brand__sub{writing-mode:vertical-rl;font-size:9px;letter-spacing:.14em}
  .rail-brand__locale{display:none}

  .nav-toggle{display:none}
  .nav-scrim{display:none}
  .nav-drawer{
    position:static;display:flex;flex:1 1 auto;flex-direction:column;
    width:auto;min-height:0;padding:0;
    background:none;border:0;box-shadow:none;
    transform:none;visibility:visible;overflow:visible;
  }

  .site-nav{flex:1 1 auto;display:flex;flex-direction:column;justify-content:center;overflow-y:auto;padding:6px 0}
  .site-nav__list{display:flex;flex-direction:column}
  .site-nav__link{
    position:relative;display:flex;flex-direction:column;align-items:center;gap:6px;
    padding:11px 2px;
    color:rgba(255,255,255,.72);
    border-bottom:0;
    transition:background-color .18s var(--ease),color .18s var(--ease);
  }
  .site-nav__link::after{content:"";position:absolute;right:7px;top:50%;width:10px;height:1px;background:var(--orange);opacity:0;transition:opacity .18s var(--ease)}
  .site-nav__num{font-size:10px;letter-spacing:.1em;color:var(--teal)}
  .site-nav__text{writing-mode:vertical-rl;font-size:12px;letter-spacing:.18em;line-height:1.1}
  .site-nav__link:hover{color:var(--white);background:rgba(255,255,255,.07)}
  .site-nav__link:hover::after{opacity:1}
  .site-nav__link:hover .site-nav__num{color:var(--orange)}
  .site-nav__link[aria-current="page"]{background:rgba(255,107,53,.16);color:var(--white);font-weight:700}
  .site-nav__link[aria-current="page"] .site-nav__num{color:var(--orange)}
  .site-nav__link[aria-current="page"]::after{opacity:1;right:0;top:0;bottom:0;width:2px;height:auto}

  .rail-actions{margin-top:0;border-top:1px solid rgba(255,255,255,.14)}
  .rail-search{text-align:center;writing-mode:vertical-rl;padding:14px 0;font-size:11px;letter-spacing:.16em;border-bottom:1px solid rgba(255,255,255,.14)}
  .rail-cta{writing-mode:vertical-rl;padding:18px 0;font-size:13px;letter-spacing:.16em}

  .rail-progress{position:absolute;top:0;bottom:0;left:auto;right:0;width:2px;height:auto}
  .rail-progress__bar{transform:scaleY(0);transform-origin:center top}
}

/* 低高度轨道压缩 */
@media (min-width:768px) and (max-height:880px){
  .rail-brand__sub{display:none}
  .site-nav__link{padding:8px 2px;gap:4px}
  .site-nav__text{font-size:11px;letter-spacing:.12em}
  .rail-cta{padding:14px 0;font-size:12px;letter-spacing:.1em}
  .rail-search{padding:10px 0;font-size:10px}
}
@media (min-width:768px) and (max-height:720px){
  .site-nav__text{display:none}
  .site-nav__link{padding:10px 2px}
}

/* ============ FOOTER ============ */
.site-footer{background:var(--ink);color:rgba(255,255,255,.78);border-top:1px solid rgba(46,196,182,.28)}
.footer-inner{max-width:var(--maxw);margin:0 auto;padding:clamp(40px,6vw,72px) clamp(16px,4vw,40px) 24px}

.footer-top{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:20px;padding-bottom:clamp(24px,3vw,36px);border-bottom:1px solid rgba(255,255,255,.12)}
.footer-closing{font-family:var(--font-display);font-weight:900;font-size:clamp(20px,2.6vw,28px);line-height:1.3;letter-spacing:-.01em;color:var(--white);max-width:24em}

.footer-grid{display:grid;grid-template-columns:1fr;gap:28px 24px;padding:clamp(24px,3.4vw,40px) 0}
@media (min-width:600px){.footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (min-width:1000px){.footer-grid{grid-template-columns:repeat(4,minmax(0,1fr))}}

.footer-col__title{display:flex;align-items:baseline;gap:8px;padding-bottom:10px;margin-bottom:10px;font-family:var(--font-body);font-weight:700;font-size:13px;line-height:1.4;letter-spacing:.08em;color:var(--white);border-bottom:1px solid rgba(255,255,255,.16)}
.footer-col__num{font-family:var(--font-mono);font-size:10px;letter-spacing:.12em;color:var(--teal)}
.footer-list__link{display:block;padding:7px 0;font-size:14px;color:rgba(255,255,255,.72);transition:color .18s var(--ease),transform .18s var(--ease)}
.footer-list__link:hover{color:var(--teal);transform:translateX(3px)}

.footer-contact{display:grid;grid-template-columns:1fr;gap:18px;padding:clamp(22px,3vw,32px) 0;border-top:1px solid rgba(255,255,255,.12)}
@media (min-width:768px){.footer-contact{grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}}
.footer-contact__label{display:block;margin-bottom:6px;font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;color:var(--teal)}
.footer-contact__value{display:block;font-size:14px;line-height:1.65;color:var(--white);word-break:break-word}

.footer-note{font-size:12px;line-height:1.7;color:rgba(255,255,255,.58);padding-bottom:20px;border-bottom:1px solid rgba(255,255,255,.12)}

.footer-legal{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 24px;padding-top:18px;font-size:12px;color:rgba(255,255,255,.55)}
.footer-legal__meta{font-family:var(--font-mono);font-size:11px;letter-spacing:.08em}

/* ============ reduced motion ============ */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  [data-reveal]{opacity:1;transform:none;transition:none}
  .btn:hover,.card:hover,.footer-list__link:hover,.search-layer__link:hover{transform:none}
  .nav-drawer,.nav-scrim,.nav-toggle__bar,.btn,.card,.rail-search,.rail-cta{transition-duration:.01ms}
}