/* =========================================================
   优发国际址中文站 · 共享样式 /assets/site.css
   设计逻辑：潮汐分层 + 档案并置；框架式导航；前强后稳
   ========================================================= */

/* ---------- 1. 令牌 ---------- */
:root{
  --deep:#0B3B4F;
  --tide:#14566E;
  --ink:#06232F;
  --mist:#E6EEF1;
  --paper:#F7F4ED;
  --coral:#FF6B4A;
  --sand:#E8C07A;
  --stone:#5C6A70;
  --moss:#6E8B6A;
  --clay:#A9624A;

  --mast-h:64px;
  --rail-w:0px;
  --wrap:1180px;
  --wrap-wide:1440px;

  --font-title:"Source Han Sans SC","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Source Han Serif SC","Noto Serif SC","Songti SC","SimSun",Georgia,serif;
  --font-mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --r-lg:28px;
  --r-md:20px;
  --r-sm:12px;
  --r-pill:999px;

  --ease:cubic-bezier(.22,.61,.36,1);
  --hairline:rgba(230,238,241,.12);
  --hairline-dark:rgba(11,59,79,.12);
  --lift:0 10px 26px rgba(6,35,47,.28);
}

@media (min-width:1025px){
  :root{ --mast-h:72px; --rail-w:68px; }
}

/* ---------- 2. reset ---------- */
*,*::before,*::after{ box-sizing:border-box; }

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
}

body{
  margin:0;
  min-height:100vh;
  padding-top:var(--mast-h);
  padding-left:var(--rail-w);
  background:var(--deep);
  color:var(--mist);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.9;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img,svg,video{ max-width:100%; display:block; }
a{ color:inherit; }
ul,ol{ margin:0; padding:0; list-style:none; }
h1,h2,h3,h4,h5,p,figure,blockquote{ margin:0; }
button,input,select,textarea{ font:inherit; color:inherit; }
[hidden]{ display:none !important; }

:focus-visible{
  outline:2px solid var(--sand);
  outline-offset:3px;
  box-shadow:0 0 0 4px rgba(232,192,122,.22);
}

/* ---------- 3. 跳转链接 ---------- */
.skip-link{
  position:fixed;
  left:14px;
  top:10px;
  z-index:200;
  transform:translateY(-180%);
  display:inline-block;
  padding:10px 20px;
  border-radius:var(--r-pill);
  background:var(--sand);
  color:var(--ink);
  font-family:var(--font-title);
  font-size:14px;
  font-weight:700;
  letter-spacing:.08em;
  text-decoration:none;
  transition:transform 220ms var(--ease);
}
.skip-link:focus{ transform:translateY(0); }

/* ---------- 4. 页头：顶栏 + 左缘导航轨 ---------- */
.site-header{ position:relative; z-index:60; }

.masthead{
  position:fixed;
  top:0;
  left:0;
  right:0;
  height:var(--mast-h);
  z-index:60;
  display:flex;
  align-items:center;
  background:var(--deep);
  border-bottom:1px solid var(--hairline);
}

.masthead__inner{
  width:100%;
  max-width:var(--wrap-wide);
  margin:0 auto;
  padding:0 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:14px;
}

.brand{
  display:flex;
  align-items:baseline;
  gap:12px;
  min-width:0;
  flex:1 1 auto;
  text-decoration:none;
}

.brand__mark{
  font-family:var(--font-title);
  font-size:20px;
  font-weight:800;
  letter-spacing:.16em;
  color:var(--mist);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.brand__line{
  font-family:var(--font-title);
  font-size:11.5px;
  font-weight:400;
  letter-spacing:.1em;
  color:rgba(230,238,241,.55);
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

.masthead__tools{
  display:flex;
  align-items:center;
  gap:9px;
  flex:0 0 auto;
}

.version-chip{
  display:inline-block;
  padding:3px 11px;
  border-radius:var(--r-pill);
  background:rgba(232,192,122,.14);
  color:var(--sand);
  font-size:12px;
  letter-spacing:.06em;
  line-height:1.6;
}

.lang-switch{
  display:inline-flex;
  align-items:center;
  gap:2px;
  padding:3px;
  border-radius:var(--r-pill);
  background:rgba(230,238,241,.09);
}

.lang-switch__btn{
  border:0;
  padding:5px 9px;
  border-radius:var(--r-pill);
  background:transparent;
  color:rgba(230,238,241,.78);
  font-family:var(--font-title);
  font-size:12px;
  font-weight:700;
  letter-spacing:.04em;
  line-height:1.4;
  cursor:pointer;
  transition:background-color 200ms var(--ease),color 200ms var(--ease);
}
.lang-switch__btn:hover{ color:var(--sand); }
.lang-switch__btn[aria-pressed="true"]{
  background:var(--sand);
  color:var(--ink);
}

/* 按钮 */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  border:0;
  padding:12px 24px;
  border-radius:var(--r-pill);
  font-family:var(--font-title);
  font-size:15px;
  font-weight:700;
  letter-spacing:.06em;
  line-height:1.4;
  text-decoration:none;
  cursor:pointer;
  transition:transform 200ms var(--ease),box-shadow 200ms var(--ease),
             background-color 200ms var(--ease),color 200ms var(--ease),
             border-color 200ms var(--ease);
}
.btn:hover{
  transform:translateX(4px);
  box-shadow:0 4px 0 rgba(6,35,47,.22);
}
.btn:active{ transform:translateX(2px); }

.btn--coral{ background:var(--coral); color:var(--ink); }
.btn--coral:hover{ box-shadow:0 4px 0 rgba(255,107,74,.35); }

.btn--ghost{
  background:transparent;
  color:var(--mist);
  border:1px solid rgba(230,238,241,.32);
}
.btn--ghost:hover{
  color:var(--sand);
  border-color:var(--sand);
  background:rgba(232,192,122,.1);
}

.btn--sm{
  padding:8px 16px;
  font-size:13px;
  letter-spacing:.04em;
}

/* 菜单按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:8px 14px;
  border:1px solid rgba(230,238,241,.3);
  border-radius:var(--r-pill);
  background:transparent;
  color:var(--mist);
  font-family:var(--font-title);
  font-size:13px;
  font-weight:700;
  letter-spacing:.08em;
  line-height:1.4;
  cursor:pointer;
  transition:background-color 200ms var(--ease),border-color 200ms var(--ease),color 200ms var(--ease);
}
.nav-toggle:hover{
  background:rgba(230,238,241,.09);
  border-color:var(--sand);
  color:var(--sand);
}

.nav-toggle__bars{
  position:relative;
  display:block;
  width:14px;
  height:2px;
  border-radius:2px;
  background:currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:14px;
  height:2px;
  border-radius:2px;
  background:currentColor;
}
.nav-toggle__bars::before{ top:-5px; }
.nav-toggle__bars::after{ top:5px; }

/* 左缘导航轨：桌面端竖排 */
.nav-rail{
  position:fixed;
  top:var(--mast-h);
  left:0;
  bottom:0;
  width:68px;
  z-index:55;
  display:flex;
  flex-direction:column;
  align-items:center;
  padding:22px 0 30px;
  background:var(--deep);
  overflow-y:auto;
  overflow-x:hidden;
  scrollbar-width:none;
}
.nav-rail::-webkit-scrollbar{ display:none; }

.nav-rail__list{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:6px;
  width:100%;
}

.nav-rail__link{
  display:inline-block;
  writing-mode:vertical-rl;
  text-orientation:mixed;
  padding:12px 9px;
  border-radius:var(--r-pill);
  color:var(--mist);
  font-family:var(--font-title);
  font-size:13px;
  font-weight:700;
  letter-spacing:.14em;
  line-height:1.2;
  text-decoration:none;
  transition:background-color 200ms var(--ease),color 200ms var(--ease),transform 200ms var(--ease);
}
.nav-rail__link:hover{
  background:rgba(232,192,122,.16);
  color:var(--sand);
  transform:translateX(3px);
}
.nav-rail__link[aria-current="page"]{
  background:var(--coral);
  color:var(--ink);
}

/* 滚动进度潮线 */
.tide-progress{
  position:fixed;
  left:0;
  top:var(--mast-h);
  width:4px;
  height:0;
  z-index:70;
  pointer-events:none;
  border-radius:0 4px 4px 0;
  background:linear-gradient(180deg,var(--sand) 0%,var(--coral) 100%);
  transition:height 120ms linear;
}

/* ---------- 5. 页脚 ---------- */
.site-footer{
  background:var(--ink);
  color:var(--mist);
  padding:66px 0 30px;
}

.footer-inner{
  width:100%;
  max-width:var(--wrap);
  margin:0 auto;
  padding:0 20px;
}

.footer-head{
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,2fr);
  gap:48px;
  padding-bottom:42px;
}

.footer-brand{ min-width:0; }

.footer-brand__mark{
  display:inline-block;
  font-family:var(--font-title);
  font-size:26px;
  font-weight:800;
  letter-spacing:.16em;
  color:var(--mist);
  text-decoration:none;
}

.footer-slogan{
  margin-top:12px;
  font-family:var(--font-title);
  font-size:14px;
  font-weight:700;
  letter-spacing:.16em;
  color:var(--sand);
}

.footer-note{
  margin-top:14px;
  max-width:22em;
  font-size:14px;
  line-height:1.9;
  color:rgba(230,238,241,.62);
}

.footer-nav{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:26px;
}

.footer-col__title{
  margin-bottom:14px;
  font-family:var(--font-title);
  font-size:13px;
  font-weight:700;
  letter-spacing:.16em;
  color:var(--sand);
}

.footer-list li + li{ margin-top:9px; }

.footer-list a{
  display:inline-block;
  font-size:14px;
  line-height:1.8;
  color:rgba(230,238,241,.78);
  text-decoration:none;
  transition:color 200ms var(--ease),transform 200ms var(--ease);
}
.footer-list a:hover{
  color:var(--sand);
  transform:translateX(4px);
}

.footer-contact{
  display:grid;
  gap:10px;
  padding-top:24px;
  border-top:1px solid rgba(230,238,241,.12);
}

.footer-contact__line{
  font-size:13.5px;
  line-height:1.85;
  color:rgba(230,238,241,.7);
}
.footer-contact__line .mono{ color:var(--sand); }

.footer-meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:8px 22px;
  margin-top:24px;
  font-family:var(--font-title);
  font-size:12.5px;
  letter-spacing:.04em;
  color:var(--stone);
}
.footer-meta__line{ margin:0; }

/* ---------- 6. 容器与区块 ---------- */
.container{
  width:100%;
  max-width:var(--wrap);
  margin:0 auto;
  padding:0 20px;
}
.container--narrow{ max-width:860px; }

.section{
  padding:72px 0;
  background:var(--deep);
  color:var(--mist);
}
.section--mist{ background:var(--mist); color:var(--ink); }
.section--paper{ background:var(--paper); color:var(--ink); }
.section--tide{ background:var(--tide); color:var(--mist); }
.section--deep{ background:var(--deep); color:var(--mist); }
.section--tight{ padding:44px 0; }
.section--loose{ padding:104px 0; }

/* ---------- 7. 栅格与节奏 ---------- */
.grid{
  display:grid;
  gap:24px;
}
.grid--5-7{ grid-template-columns:minmax(0,5fr) minmax(0,7fr); }
.grid--7-5{ grid-template-columns:minmax(0,7fr) minmax(0,5fr); }
.grid--4-8{ grid-template-columns:minmax(0,4fr) minmax(0,8fr); }
.grid--2{ grid-template-columns:repeat(2,minmax(0,1fr)); }
.grid--3{ grid-template-columns:repeat(3,minmax(0,1fr)); }

.stack > * + *{ margin-top:var(--stack-gap,16px); }

.rule{
  height:1px;
  border:0;
  margin:0;
  background:var(--hairline);
}
.section--mist .rule,
.section--paper .rule{ background:var(--hairline-dark); }

.band{
  padding:36px 30px;
  border-radius:var(--r-lg);
  background:var(--tide);
  color:var(--mist);
}

/* ---------- 8. 排版组件 ---------- */
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:9px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.16em;
  line-height:1.6;
  color:var(--sand);
  font-variant-numeric:tabular-nums;
}
.eyebrow::before{
  content:"";
  width:6px;
  height:6px;
  border-radius:50%;
  background:currentColor;
  flex:0 0 auto;
}
.section--mist .eyebrow,
.section--paper .eyebrow{ color:var(--clay); }

.sidenote{
  font-family:var(--font-title);
  font-size:12.5px;
  font-weight:700;
  letter-spacing:.18em;
  line-height:1.7;
  color:var(--sand);
  opacity:.8;
}
.section--mist .sidenote,
.section--paper .sidenote{ color:var(--clay); opacity:1; }

.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.02em;
}

.lede{
  max-width:30em;
  font-size:19px;
  line-height:1.85;
  color:rgba(230,238,241,.84);
}
.section--mist .lede,
.section--paper .lede{ color:rgba(11,59,79,.8); }

.prose{
  max-width:38em;
  font-size:17px;
  line-height:1.9;
}
.prose p + p{ margin-top:1em; }
.prose h2{
  margin:1.8em 0 .6em;
  font-family:var(--font-title);
  font-size:1.5rem;
  font-weight:800;
  letter-spacing:.05em;
  line-height:1.45;
}
.prose h3{
  margin:1.5em 0 .5em;
  font-family:var(--font-title);
  font-size:1.15rem;
  font-weight:700;
  letter-spacing:.05em;
  line-height:1.5;
}
.prose ul,
.prose ol{
  margin:1em 0;
  padding-left:1.3em;
  list-style:disc;
}
.prose ol{ list-style:decimal; }
.prose li + li{ margin-top:.42em; }
.prose a{
  color:var(--sand);
  text-underline-offset:3px;
  transition:color 200ms var(--ease);
}
.prose a:hover{ color:var(--coral); }
.section--mist .prose a,
.section--paper .prose a{ color:var(--tide); }
.section--mist .prose a:hover,
.section--paper .prose a:hover{ color:var(--clay); }

/* ---------- 9. 胶囊 / 色点 / 卡片 / 图 ---------- */
.pill{
  display:inline-flex;
  align-items:center;
  gap:7px;
  padding:7px 15px;
  border-radius:var(--r-pill);
  background:rgba(230,238,241,.12);
  color:var(--mist);
  font-family:var(--font-title);
  font-size:13px;
  font-weight:700;
  letter-spacing:.08em;
  line-height:1.5;
  text-decoration:none;
  border:0;
  cursor:pointer;
  transition:transform 200ms var(--ease),box-shadow 200ms var(--ease),
             background-color 200ms var(--ease),color 200ms var(--ease);
}
a.pill:hover,
button.pill:hover{
  transform:translateX(4px);
  box-shadow:0 4px 0 rgba(6,35,47,.2);
}

.pill--coral{ background:var(--coral); color:var(--ink); }
.pill--sand{ background:var(--sand); color:var(--ink); }
.pill--moss{ background:var(--moss); color:#0A1C12; }
.pill--quiet{ background:rgba(11,59,79,.1); color:var(--deep); }

.section--mist .pill,
.section--paper .pill{
  background:rgba(11,59,79,.1);
  color:var(--deep);
}
.section--mist .pill--coral,
.section--paper .pill--coral{ background:var(--coral); color:var(--ink); }
.section--mist .pill--sand,
.section--paper .pill--sand{ background:var(--sand); color:var(--ink); }
.section--mist .pill--moss,
.section--paper .pill--moss{ background:var(--moss); color:#0A1C12; }

.dot{
  display:inline-block;
  width:9px;
  height:9px;
  border-radius:50%;
  background:var(--stone);
  flex:0 0 auto;
}
.dot--desktop{ background:var(--coral); }
.dot--mobile{ background:var(--sand); }
.dot--both{ background:var(--moss); }

.card{
  padding:26px 24px;
  border-radius:var(--r-lg);
  background:var(--tide);
  color:var(--mist);
  transition:transform 220ms var(--ease),box-shadow 220ms var(--ease);
}
.card:hover{
  transform:translateY(-3px);
  box-shadow:var(--lift);
}
.card--paper{ background:var(--paper); color:var(--ink); }
.card--tide{ background:var(--tide); color:var(--mist); }

.figure{
  margin:0;
  overflow:hidden;
  border-radius:var(--r-lg);
  background:var(--tide);
}

.figure__img{
  display:block;
  width:100%;
  aspect-ratio:16 / 9;
  object-fit:cover;
  background:linear-gradient(150deg,var(--tide) 0%,var(--deep) 60%,var(--ink) 100%);
}
.figure__img--wide{ aspect-ratio:21 / 9; }
.figure__img--tall{ aspect-ratio:4 / 5; }

.figure__cap{
  display:block;
  padding:12px 18px;
  background:rgba(6,35,47,.55);
  color:rgba(230,238,241,.66);
  font-family:var(--font-title);
  font-size:12.5px;
  letter-spacing:.06em;
  line-height:1.7;
}

/* ---------- 10. 面包屑 ---------- */
.crumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  padding:16px 0;
  font-family:var(--font-title);
  font-size:12.5px;
  letter-spacing:.08em;
  line-height:1.7;
  color:rgba(230,238,241,.6);
}
.crumb a{
  color:rgba(230,238,241,.6);
  text-decoration:none;
  transition:color 200ms var(--ease);
}
.crumb a:hover{ color:var(--sand); }
.crumb__sep{ color:rgba(230,238,241,.32); }
.crumb__current{ color:var(--sand); }

.section--mist .crumb,
.section--paper .crumb{ color:var(--stone); }
.section--mist .crumb a,
.section--paper .crumb a{ color:var(--stone); }
.section--mist .crumb a:hover,
.section--paper .crumb a:hover{ color:var(--clay); }
.section--mist .crumb__sep,
.section--paper .crumb__sep{ color:rgba(92,106,112,.55); }
.section--mist .crumb__current,
.section--paper .crumb__current{ color:var(--clay); }

/* ---------- 11. 响应式 ---------- */
@media (max-width:1200px){
  .footer-head{ gap:36px; }
}

@media (max-width:1024px){
  .nav-toggle{ display:inline-flex; }

  .nav-rail{
    top:var(--mast-h);
    left:0;
    right:0;
    bottom:auto;
    width:auto;
    max-height:0;
    padding:0 16px;
    display:block;
    background:var(--ink);
    overflow:hidden;
    opacity:0;
    pointer-events:none;
    transition:max-height 320ms var(--ease),opacity 240ms var(--ease),padding 240ms var(--ease);
    scrollbar-width:none;
  }
  .nav-rail::-webkit-scrollbar{ display:none; }

  .site-header[data-open="true"] .nav-rail{
    max-height:calc(100vh - var(--mast-h) - 12px);
    padding:14px 16px 22px;
    overflow-y:auto;
    opacity:1;
    pointer-events:auto;
  }

  .nav-rail__list{
    flex-direction:column;
    align-items:stretch;
    gap:3px;
  }

  .nav-rail__link{
    writing-mode:horizontal-tb;
    text-orientation:initial;
    display:flex;
    align-items:center;
    padding:13px 16px;
    border-radius:var(--r-md);
    font-size:16px;
    letter-spacing:.1em;
  }
  .nav-rail__link:hover{
    transform:none;
    background:rgba(232,192,122,.14);
  }
  .nav-rail__link[aria-current="page"]{
    background:var(--coral);
    color:var(--ink);
  }

  .footer-head{
    grid-template-columns:minmax(0,1fr);
    gap:38px;
  }
}

@media (max-width:900px){
  .masthead__tools .btn--ghost{ display:none; }
  .footer-nav{ grid-template-columns:repeat(2,minmax(0,1fr)); gap:22px; }
}

@media (max-width:860px){
  .section{ padding:52px 0; }
  .section--tight{ padding:32px 0; }
  .section--loose{ padding:72px 0; }

  .grid--5-7,
  .grid--7-5,
  .grid--4-8,
  .grid--2,
  .grid--3{ grid-template-columns:minmax(0,1fr); }

  body{ font-size:16px; line-height:1.85; }
  .lede{ font-size:17.5px; }
  .prose{ font-size:16px; line-height:1.85; }
  .band{ padding:26px 20px; }
  .card{ padding:22px 18px; }
  .footer-brand__mark{ font-size:22px; }
}

@media (max-width:720px){
  .masthead__tools .btn--coral{ display:none; }
  .version-chip{ display:none; }
  .brand__mark{ font-size:17px; letter-spacing:.12em; }
  .brand__line{ display:none; }
  .skip-link{ left:10px; }
  .footer-meta{ justify-content:flex-start; }
}

@media (max-width:480px){
  .footer-nav{ grid-template-columns:minmax(0,1fr); }
}

/* ---------- 12. 减少动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{ scroll-behavior:auto; }

  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }

  .btn:hover,
  a.pill:hover,
  button.pill:hover,
  .footer-list a:hover,
  .nav-rail__link:hover{ transform:none; }

  .card:hover{ transform:none; }

  .tide-progress{ transition:none; opacity:.75; }
}