/* ============================================================
   安信主页 · 共享样式表  /assets/site.css
   展览画册式导航手册：深色刊头 · 非对称索引 · 紧凑页脚
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root{
  --ink-900:#0B2A33;
  --teal-800:#0E5C63;
  --teal-600:#12808A;
  --teal-100:#D9EEF0;
  --mist-50:#F4F9F9;
  --action-500:#F26522;
  --action-600:#D9541A;
  --action-100:#FFE4D4;
  --amber-400:#F5A623;
  --graphite-700:#2B3A3F;
  --line-300:#C9D6D8;
  --white:#FFFFFF;
  --success-600:#1E8E5A;
  --alert-600:#C0392B;

  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;

  --wrap:1240px;
  --gutter:24px;
  --radius:2px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --dur:160ms;
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{margin:0;}
h1,h2,h3,h4,p,figure,blockquote,dl,dd{margin:0;}
ul,ol{margin:0;padding:0;list-style:none;}
img,svg{display:block;max-width:100%;}
button,input,select,textarea{font:inherit;color:inherit;}
a{color:inherit;text-decoration:none;}
[hidden]{display:none !important;}
[id]{scroll-margin-top:140px;}

/* ---------- 3. 基础排版 ---------- */
body{
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  color:var(--graphite-700);
  background:var(--mist-50);
  font-weight:400;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4{color:var(--ink-900);font-weight:700;line-height:1.2;letter-spacing:-.01em;}
strong,b{font-weight:700;color:var(--ink-900);}
::selection{background:var(--action-100);color:var(--ink-900);}

:focus-visible{outline:2px solid var(--action-500);outline-offset:2px;border-radius:1px;}

.skip-link{
  position:absolute;
  left:50%;
  top:-100px;
  transform:translateX(-50%);
  z-index:200;
  background:var(--action-500);
  color:#fff;
  font-size:14px;
  font-weight:700;
  letter-spacing:.08em;
  padding:12px 22px;
  border-radius:0 0 var(--radius) var(--radius);
  transition:top var(--dur) var(--ease);
}
.skip-link:focus{top:0;}

/* ---------- 4. 刊头 / header ---------- */
.masthead{
  position:sticky;
  top:0;
  z-index:80;
  background:var(--ink-900);
  color:#fff;
  border-bottom:1px solid var(--teal-800);
}
.masthead__inner{
  position:relative;
  width:100%;
  max-width:var(--wrap);
  margin:0 auto;
  padding:0 var(--gutter);
}
.masthead__top{
  position:relative;
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:78px;
  padding:12px 0;
}
.masthead__brand{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:6px;
  text-align:center;
}
.masthead__brand-mark{
  width:60px;
  height:3px;
  background:repeating-linear-gradient(to right,var(--action-500) 0 8px,transparent 8px 13px);
}
.masthead__brand-name{
  font-size:clamp(1.35rem,2.4vw,1.7rem);
  font-weight:900;
  letter-spacing:.1em;
  color:#fff;
  line-height:1.1;
}
.masthead__brand-sub{
  font-size:12px;
  letter-spacing:.16em;
  color:#8fb4b8;
  line-height:1.5;
}
.masthead__quick{
  position:absolute;
  right:0;
  top:50%;
  transform:translateY(-50%);
  display:flex;
  gap:8px;
}
.quick-link{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:40px;
  padding:0 16px;
  font-size:14px;
  font-weight:500;
  letter-spacing:.06em;
  color:#fff;
  border:1px solid rgba(255,255,255,.3);
  border-radius:var(--radius);
  transition:background-color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),
             color var(--dur) var(--ease);
}
.quick-link:hover{
  background:rgba(255,255,255,.1);
  border-color:#fff;
}
.quick-link--action{
  background:var(--action-500);
  border-color:var(--action-500);
  font-weight:700;
}
.quick-link--action:hover{
  background:var(--action-600);
  border-color:var(--action-600);
}

/* 栏目带 */
.masthead__nav-row{
  border-top:1px solid rgba(255,255,255,.12);
}
.nav{display:block;}
.nav__list{
  display:flex;
  flex-wrap:wrap;
  justify-content:center;
  align-items:center;
}
.nav__item{border-left:1px solid rgba(255,255,255,.08);}
.nav__item:first-child{border-left:0;}
.nav__link{
  position:relative;
  display:block;
  padding:14px 18px;
  font-size:15px;
  letter-spacing:.08em;
  color:#cfe3e5;
  transition:color var(--dur) var(--ease);
}
.nav__link::before{
  content:"";
  display:inline-block;
  width:6px;
  height:6px;
  margin-right:0;
  background:var(--action-500);
  vertical-align:middle;
  opacity:0;
  transition:opacity var(--dur) var(--ease),margin var(--dur) var(--ease);
}
.nav__link::after{
  content:"";
  position:absolute;
  left:18px;
  right:18px;
  bottom:8px;
  height:2px;
  background:var(--action-500);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform var(--dur) var(--ease);
}
.nav__link:hover{color:#fff;}
.nav__link:hover::after{transform:scaleX(1);}
.nav__link[aria-current="page"]{
  color:#fff;
  font-weight:700;
}
.nav__link[aria-current="page"]::before{
  opacity:1;
  margin-right:8px;
}
.nav__link[aria-current="page"]::after{transform:scaleX(1);}

/* 移动导航按钮 */
.nav-toggle{
  display:none;
  width:100%;
  align-items:center;
  justify-content:center;
  gap:10px;
  padding:15px 0;
  background:transparent;
  border:0;
  color:#cfe3e5;
  font-size:14px;
  letter-spacing:.16em;
  cursor:pointer;
}
.nav-toggle__bars{
  position:relative;
  display:inline-block;
  width:18px;
  height:2px;
  background:currentColor;
  transition:background-color var(--dur) var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:18px;
  height:2px;
  background:currentColor;
  transition:transform var(--dur) var(--ease);
}
.nav-toggle__bars::before{top:-6px;}
.nav-toggle__bars::after{top:6px;}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:var(--action-500);}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(6px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-6px) rotate(-45deg);}

/* 刊头刻度条与进度 */
.masthead__rule{
  height:4px;
  background:
    repeating-linear-gradient(to right,var(--action-500) 0 14px,transparent 14px 24px),
    linear-gradient(to right,var(--teal-600),var(--teal-800));
}
.scroll-progress{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:3px;
  background:var(--amber-400);
  transform:scaleX(0);
  transform-origin:left center;
  pointer-events:none;
  will-change:transform;
}

/* ---------- 5. 内容容器与分区 ---------- */
.wrap{
  width:100%;
  max-width:var(--wrap);
  margin:0 auto;
  padding:0 var(--gutter);
}
.wrap--narrow{max-width:840px;}
.section{padding:clamp(44px,6vw,92px) 0;}
.section--tight{padding:clamp(28px,4vw,52px) 0;}
.section--mist{background:var(--mist-50);}
.section--white{background:var(--white);}
.section--ink{background:var(--ink-900);color:#fff;}
.section--ink h1,.section--ink h2,.section--ink h3{color:#fff;}

.grid{
  display:grid;
  gap:clamp(20px,3vw,44px);
  align-items:start;
}
.grid--7-5{grid-template-columns:7fr 5fr;}
.grid--5-7{grid-template-columns:5fr 7fr;}

.eyebrow{
  display:inline-block;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.18em;
  color:var(--teal-600);
  text-transform:uppercase;
}
.lede{
  font-size:clamp(1.05rem,1.6vw,1.22rem);
  line-height:1.7;
  color:var(--ink-900);
  max-width:44ch;
}
.prose{max-width:72ch;}
.prose p + p{margin-top:1.2em;}
.prose h2{margin-top:1.8em;margin-bottom:.6em;}
.prose h3{margin-top:1.5em;margin-bottom:.5em;font-size:1.15rem;}
.prose ul,.prose ol{margin:1em 0;padding-left:1.4em;list-style:disc;}
.prose ol{list-style:decimal;}
.prose li + li{margin-top:.5em;}
.prose a{color:var(--teal-800);border-bottom:1px solid var(--teal-600);}
.prose a:hover{color:var(--action-600);border-color:var(--action-500);}
.rule{
  height:1px;
  border:0;
  margin:0;
  background:var(--line-300);
}
.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-weight:500;
  letter-spacing:.02em;
}

/* ---------- 6. 横向主题带 ---------- */
.band{
  background:var(--teal-100);
  border-top:1px solid var(--line-300);
  border-bottom:1px solid var(--line-300);
}
.band--ink{
  background:var(--ink-900);
  border-color:var(--teal-800);
  color:#fff;
}
.band__inner{
  max-width:var(--wrap);
  margin:0 auto;
  padding:clamp(22px,3.5vw,38px) var(--gutter);
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:clamp(14px,3vw,40px);
}
.band__index{
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.12em;
  color:var(--teal-800);
  padding-left:12px;
  border-left:3px solid var(--action-500);
  white-space:nowrap;
}
.band__title{
  font-size:clamp(1.1rem,2vw,1.5rem);
  font-weight:700;
  color:var(--ink-900);
  line-height:1.3;
}
.band--ink .band__index{color:var(--amber-400);}
.band--ink .band__title{color:#fff;}

/* ---------- 7. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  min-height:48px;
  padding:0 22px;
  font-size:15px;
  font-weight:700;
  letter-spacing:.06em;
  text-align:center;
  border:1px solid transparent;
  border-radius:var(--radius);
  cursor:pointer;
  transition:background-color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),
             color var(--dur) var(--ease);
}
.btn--action{background:var(--action-500);color:#fff;border-color:var(--action-500);}
.btn--action:hover{background:var(--action-600);border-color:var(--action-600);}
.btn--outline{background:var(--white);color:var(--teal-800);border-color:var(--teal-600);}
.btn--outline:hover{background:var(--teal-100);color:var(--ink-900);}
.btn--dark{background:var(--ink-900);color:#fff;border-color:var(--ink-900);}
.btn--dark:hover{background:var(--teal-800);border-color:var(--teal-800);}
.btn--lg{min-height:58px;padding:0 32px;font-size:17px;}
.btn-group{
  display:flex;
  flex-wrap:wrap;
  gap:12px;
  align-items:center;
}

/* ---------- 8. 面包屑 ---------- */
.crumb{
  font-size:13px;
  letter-spacing:.08em;
  color:var(--teal-800);
}
.crumb__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
}
.crumb__item{display:flex;align-items:center;gap:8px;}
.crumb__item + .crumb__item::before{
  content:"/";
  color:var(--line-300);
}
.crumb__link{
  color:var(--teal-600);
  border-bottom:1px solid transparent;
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.crumb__link:hover{color:var(--action-600);border-color:var(--action-500);}
.crumb__current{color:var(--graphite-700);}

/* ---------- 9. 图版容器（响应式图片占位） ---------- */
.plate{
  position:relative;
  margin:0;
  padding:12px;
  background:var(--white);
  border:1px solid var(--line-300);
}
.plate__media{
  display:block;
  width:100%;
  aspect-ratio:16 / 10;
  background:linear-gradient(135deg,var(--teal-100) 0%,var(--mist-50) 100%);
  overflow:hidden;
}
.plate__media > img,
.plate__media > svg{
  width:100%;
  height:100%;
  object-fit:cover;
}
.plate__caption{
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:8px 16px;
  margin-top:12px;
  font-size:13px;
  letter-spacing:.04em;
  color:#5b6b70;
  line-height:1.6;
}
.plate--flush{padding:0;}
.plate--wide .plate__media{aspect-ratio:21 / 9;}
.plate--portrait .plate__media{aspect-ratio:3 / 4;}
.plate--square .plate__media{aspect-ratio:1 / 1;}
.plate--ticks::before,
.plate--ticks::after{
  content:"";
  position:absolute;
  width:16px;
  height:16px;
  border:2px solid var(--action-500);
  pointer-events:none;
}
.plate--ticks::before{top:-1px;left:-1px;border-right:0;border-bottom:0;}
.plate--ticks::after{bottom:-1px;right:-1px;border-left:0;border-top:0;}

/* ---------- 10. 目录 ---------- */
.toc{
  padding:18px;
  background:var(--white);
  border:1px solid var(--line-300);
}
.toc__title{
  margin-bottom:12px;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.16em;
  color:var(--teal-800);
}
.toc__list{display:flex;flex-direction:column;gap:2px;}
.toc__link{
  display:block;
  padding:8px 12px;
  font-size:14px;
  line-height:1.6;
  color:var(--graphite-700);
  border-left:2px solid var(--line-300);
  transition:background-color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),
             color var(--dur) var(--ease);
}
.toc__link:hover{
  background:var(--mist-50);
  border-color:var(--teal-600);
  color:var(--teal-800);
}
.toc__link[aria-current]{
  background:var(--action-100);
  border-color:var(--action-500);
  color:var(--ink-900);
  font-weight:700;
}

/* ---------- 11. 页脚 ---------- */
.colophon{
  margin-top:clamp(48px,7vw,96px);
  padding:clamp(26px,4vw,42px) 0 16px;
  background:var(--ink-900);
  color:#cfe3e5;
  border-top:4px solid var(--teal-800);
}
.colophon__inner{
  width:100%;
  max-width:var(--wrap);
  margin:0 auto;
  padding:0 var(--gutter);
}
.colophon__top{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  justify-content:space-between;
  gap:10px 24px;
  padding-bottom:16px;
  border-bottom:1px solid rgba(255,255,255,.14);
}
.colophon__brand-name{
  font-size:1.2rem;
  font-weight:900;
  letter-spacing:.14em;
  color:#fff;
}
.colophon__brand-note{
  font-size:13px;
  letter-spacing:.08em;
  color:#8fb4b8;
}
.colophon__grid{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  padding:22px 0;
  border-bottom:1px solid rgba(255,255,255,.14);
}
.colophon__col{
  padding:0 22px;
  border-left:1px solid rgba(255,255,255,.12);
}
.colophon__col:first-child{
  padding-left:0;
  border-left:0;
}
.colophon__title{
  margin-bottom:10px;
  font-size:13px;
  font-weight:500;
  letter-spacing:.18em;
  color:var(--amber-400);
}
.colophon__item + .colophon__item{margin-top:7px;}
.colophon__link,
.colophon__text{
  font-size:14px;
  line-height:1.7;
  color:#cfe3e5;
  word-break:break-word;
}
.colophon__link{
  border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.colophon__link:hover{
  color:#fff;
  border-color:var(--action-500);
}
.colophon__text{color:#8fb4b8;}
.colophon__service{
  padding:14px 0 0;
  font-size:13px;
  line-height:1.9;
  color:#8fb4b8;
}
.colophon__bottom{
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:8px 20px;
  padding:12px 0 0;
  font-size:12px;
  letter-spacing:.06em;
  color:#7ba3a8;
}
.colophon__mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
}

/* ---------- 12. 响应式 ---------- */
@media (max-width:1080px){
  .masthead__top{
    flex-direction:column;
    gap:14px;
    padding:16px 0 18px;
  }
  .masthead__quick{
    position:static;
    transform:none;
    justify-content:center;
  }
}

@media (max-width:900px){
  :root{--gutter:20px;}
  .nav-toggle{display:inline-flex;}
  .nav{display:none;border-top:1px solid rgba(255,255,255,.12);}
  .nav[data-open]{display:block;}
  .nav__list{
    flex-direction:column;
    align-items:stretch;
    padding:6px 0 14px;
  }
  .nav__item{border-left:0;border-top:1px solid rgba(255,255,255,.08);}
  .nav__item:first-child{border-top:0;}
  .nav__link{padding:13px 6px;font-size:15px;}
  .nav__link::after{display:none;}
  .nav__link[aria-current="page"]{
    padding-left:14px;
    background:rgba(242,101,34,.16);
    border-radius:var(--radius);
  }
  .grid--7-5,
  .grid--5-7{grid-template-columns:1fr;}
  .colophon__grid{grid-template-columns:repeat(2,1fr);row-gap:24px;}
  .colophon__col{padding:0 18px;}
  .colophon__col:nth-child(odd){padding-left:0;border-left:0;}
  .plate__media{aspect-ratio:16 / 11;}
}

@media (max-width:560px){
  .masthead__brand-sub{letter-spacing:.1em;}
  .quick-link{flex:1 1 0;padding:0 12px;}
  .masthead__quick{width:100%;}
  .colophon__grid{grid-template-columns:1fr;row-gap:20px;}
  .colophon__col{padding:0;border-left:0;}
  .colophon__top{flex-direction:column;align-items:flex-start;}
  .btn{width:100%;}
  .btn-group{flex-direction:column;align-items:stretch;}
  .plate--portrait .plate__media{aspect-ratio:4 / 5;}
}

/* ---------- 13. 动效偏好 ---------- */
@media (prefers-reduced-motion:no-preference){
  html{scroll-behavior:smooth;}
}
@media (prefers-reduced-motion:reduce){
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
}