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

:root{
  --ink:#061826;
  --ink-soft:#0a2135;
  --panel:#0C2B45;
  --path:#1D4E6F;
  --cyan:#35E6D4;
  --orange:#FF9A4D;
  --paper:#F1E7D4;
  --paper-edge:#D8C9AE;
  --white:#F4FAFC;
  --mist:#9DB4C4;
  --green:#58D68D;
  --font-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC","Source Han Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",Menlo,Consolas,"Courier New","Noto Sans Mono CJK SC",monospace;
  --header-h:72px;
  --radius-s:8px;
  --radius-m:14px;
  --radius-l:22px;
  --edge:rgba(29,78,111,.6);
  --shadow-paper:0 22px 44px -26px rgba(0,0,0,.85);
  --dur:220ms;
}

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-h) + 24px);
}

body{
  margin:0;
  min-height:100vh;
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.75;
  color:var(--white);
  background:
    radial-gradient(1100px 620px at 82% -12%, rgba(53,230,212,.13), transparent 62%),
    radial-gradient(900px 520px at 6% 12%, rgba(255,154,77,.09), transparent 60%),
    linear-gradient(180deg,#061826 0%,#08202f 46%,#04121c 100%);
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
}

h1,h2,h3,h4,h5,h6,p,figure,blockquote{margin:0;}
img,svg,video{display:block;max-width:100%;height:auto;}
button{font:inherit;color:inherit;}
a{color:inherit;}
::selection{background:rgba(53,230,212,.32);color:#fff;}

:focus-visible{
  outline:2px solid var(--cyan);
  outline-offset:3px;
}
.skip-link:focus-visible{outline-color:var(--white);}

/* ---------- 基础容器 ---------- */
.container{
  width:100%;
  max-width:1240px;
  margin-inline:auto;
  padding-inline:clamp(16px,4vw,48px);
}
.page-top{padding-top:calc(var(--header-h) + clamp(20px,4vw,56px));}

/* ---------- 排版工具 ---------- */
.prose{
  max-width:38em;
  color:#dbe7ef;
}
.prose p{margin-bottom:1.1em;line-height:1.8;}
.prose p:last-child{margin-bottom:0;}
.prose a{color:var(--cyan);text-decoration:none;border-bottom:1px solid rgba(53,230,212,.45);}
.prose a:hover{color:var(--white);border-bottom-color:var(--white);}

.eyebrow{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.22em;
  color:var(--cyan);
  margin:0;
}

/* ---------- 网格 ---------- */
.grid{
  display:grid;
  gap:clamp(16px,2.4vw,28px);
}
.grid--bento{grid-template-columns:repeat(12,minmax(0,1fr));}

/* ---------- 图片 / 插图容器 ---------- */
.media-frame{
  position:relative;
  overflow:hidden;
  border-radius:var(--radius-m);
  border:1px solid var(--edge);
  background:linear-gradient(155deg,#0b2c44 0%,#061a29 100%);
}
.media-frame > img,
.media-frame > svg{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  background:radial-gradient(120% 85% at 88% 4%,rgba(53,230,212,.16),transparent 62%);
  pointer-events:none;
}
.media-frame--wide{aspect-ratio:16/9;}
.media-frame--square{aspect-ratio:1/1;}
.media-frame--tall{aspect-ratio:3/4;}
.media-frame__caption{
  position:absolute;
  left:12px;
  bottom:12px;
  z-index:2;
  padding:5px 10px;
  border-radius:999px;
  background:rgba(6,24,38,.82);
  border:1px solid rgba(53,230,212,.45);
  color:var(--cyan);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
}

/* ---------- 纸色卡 ---------- */
.paper-card{
  background:var(--paper);
  color:var(--ink);
  border:1px solid var(--paper-edge);
  border-radius:var(--radius-m);
  box-shadow:var(--shadow-paper);
  padding:clamp(16px,2.4vw,26px);
}

/* ---------- 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--mist);
}
.breadcrumb a{
  color:var(--mist);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color var(--dur) ease,border-color var(--dur) ease;
}
.breadcrumb a:hover{color:var(--cyan);border-bottom-color:var(--cyan);}
.breadcrumb__sep{color:var(--path);}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 20px;
  border-radius:999px;
  border:1px solid transparent;
  font-family:var(--font-sans);
  font-size:14px;
  font-weight:600;
  line-height:1.25;
  letter-spacing:.04em;
  text-decoration:none;
  white-space:nowrap;
  cursor:pointer;
  transition:transform var(--dur) ease,background-color var(--dur) ease,color var(--dur) ease,border-color var(--dur) ease,box-shadow var(--dur) ease;
}
.btn--accent{
  background:var(--orange);
  color:#20120a;
  border-color:#ffb378;
  box-shadow:0 12px 26px -18px rgba(255,154,77,.95);
}
.btn--accent:hover{background:#ffab68;transform:translateY(-1px);}
.btn--ghost{
  background:transparent;
  color:var(--cyan);
  border-color:rgba(53,230,212,.5);
}
.btn--ghost:hover{background:rgba(53,230,212,.12);color:var(--white);}
.btn--paper{
  background:var(--paper);
  color:var(--ink);
  border-color:var(--paper-edge);
}
.btn--paper:hover{background:#f8f0e1;transform:translateY(-1px);}

/* ---------- 跳至主要内容 ---------- */
.skip-link{
  position:fixed;
  top:10px;
  left:10px;
  z-index:300;
  padding:10px 18px;
  border-radius:var(--radius-s);
  background:var(--cyan);
  color:#04212b;
  font-size:14px;
  font-weight:700;
  text-decoration:none;
  transform:translateY(-180%);
  transition:transform 180ms ease;
}
.skip-link:focus-visible{transform:translateY(0);outline-offset:3px;}

/* ---------- 头部 ---------- */
.site-header{
  position:fixed;
  inset:0 0 auto 0;
  z-index:120;
  color:var(--white);
  background:linear-gradient(180deg,rgba(6,24,38,.78) 0%,rgba(6,24,38,0) 100%);
  border-bottom:1px solid transparent;
  transition:background-color var(--dur) ease,border-color var(--dur) ease,box-shadow var(--dur) ease,backdrop-filter var(--dur) ease;
}
.site-header.is-scrolled{
  background:rgba(6,24,38,.97);
  border-bottom-color:var(--edge);
  box-shadow:0 16px 34px -26px rgba(0,0,0,.95);
  backdrop-filter:blur(10px);
}
.header__inner{
  display:flex;
  align-items:center;
  gap:clamp(12px,2vw,28px);
  width:100%;
  max-width:1240px;
  min-height:var(--header-h);
  margin-inline:auto;
  padding:10px clamp(16px,4vw,48px);
}

/* 品牌 */
.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  flex:0 0 auto;
  text-decoration:none;
  color:inherit;
}
.brand__glyph{
  position:relative;
  display:grid;
  place-items:center;
  width:36px;
  height:36px;
  border-radius:10px;
  background:var(--panel);
  border:1px solid rgba(53,230,212,.55);
  box-shadow:inset 0 0 0 2px rgba(6,24,38,.9);
  color:var(--cyan);
  font-family:var(--font-sans);
  font-size:16px;
  font-weight:700;
  line-height:1;
}
.brand__glyph::after{
  content:"";
  position:absolute;
  right:-3px;
  bottom:-3px;
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--orange);
}
.brand__text{
  display:flex;
  flex-direction:column;
  line-height:1.2;
}
.brand__name{
  font-size:17px;
  font-weight:800;
  letter-spacing:.06em;
  color:var(--white);
}
.brand__tagline{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.18em;
  color:var(--cyan);
}
.brand:hover .brand__name{color:var(--cyan);}
.brand--footer .brand__glyph{width:40px;height:40px;font-size:17px;}
.brand--footer .brand__name{font-size:19px;}

/* 主导航 */
.site-nav{
  margin-inline-start:auto;
}
.site-nav__list{
  display:flex;
  align-items:center;
  gap:clamp(4px,1.2vw,16px);
  margin:0;
  padding:0;
  list-style:none;
  counter-reset:navidx;
}
.site-nav__item{
  counter-increment:navidx;
  position:relative;
}
.site-nav__link{
  position:relative;
  display:inline-flex;
  align-items:baseline;
  gap:7px;
  padding:8px 10px;
  border-radius:var(--radius-s);
  color:var(--mist);
  font-size:14px;
  letter-spacing:.02em;
  text-decoration:none;
  transition:color var(--dur) ease,background-color var(--dur) ease;
}
.site-nav__link::before{
  content:counter(navidx,decimal-leading-zero);
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.04em;
  color:var(--path);
  transition:color var(--dur) ease;
}
.site-nav__link:hover{color:var(--white);background:rgba(29,78,111,.38);}
.site-nav__link:hover::before{color:var(--cyan);}
.site-nav__link[aria-current="page"]{color:var(--white);background:rgba(29,78,111,.45);}
.site-nav__link[aria-current="page"]::before{color:var(--orange);}
.site-nav__link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:10px;
  right:10px;
  bottom:3px;
  height:2px;
  border-radius:2px;
  background:var(--orange);
}
.site-nav__actions{display:none;}
.site-nav__meta{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--mist);
}

/* 头部右侧 */
.header-actions{
  display:flex;
  align-items:center;
  gap:14px;
  flex:0 0 auto;
}
.header-utility{
  margin:0;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--mist);
  white-space:nowrap;
}

/* 移动目录按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:8px 14px;
  border-radius:10px;
  border:1px solid rgba(53,230,212,.42);
  background:rgba(12,43,69,.88);
  color:var(--white);
  font-family:var(--font-sans);
  font-size:13px;
  font-weight:600;
  letter-spacing:.06em;
  cursor:pointer;
  transition:background-color var(--dur) ease,border-color var(--dur) ease;
}
.nav-toggle:hover{background:rgba(29,78,111,.92);border-color:var(--cyan);}
.nav-toggle__bars{display:grid;gap:4px;}
.nav-toggle__bar{
  display:block;
  width:16px;
  height:2px;
  border-radius:2px;
  background:var(--cyan);
  transition:transform var(--dur) ease,opacity var(--dur) ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(6px) rotate(45deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2){opacity:0;}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3){transform:translateY(-6px) rotate(-45deg);}
.nav-toggle__label{line-height:1;}

/* ---------- 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(48px,8vw,110px);
  border-top:1px solid var(--edge);
  background:linear-gradient(180deg,rgba(12,43,69,.58) 0%,rgba(4,14,22,.98) 68%);
  color:var(--mist);
}
.footer__inner{
  width:100%;
  max-width:1240px;
  margin-inline:auto;
  padding-inline:clamp(16px,4vw,48px);
}
.footer__top{
  display:grid;
  grid-template-columns:minmax(0,1.05fr) minmax(0,1fr);
  gap:clamp(28px,4vw,64px);
  align-items:start;
  padding-block:clamp(40px,6vw,72px) clamp(24px,3vw,40px);
}
.footer__intro{min-width:0;}
.footer__summary{
  max-width:34ch;
  margin-top:20px;
  font-size:15.5px;
  line-height:1.8;
  color:#c9d9e3;
}
.footer__contact{
  display:grid;
  gap:6px;
  margin:22px 0 0;
  padding:0;
  list-style:none;
  font-size:14px;
  line-height:1.7;
  color:#b3c6d2;
}
.footer__note{
  max-width:40ch;
  margin-top:16px;
  font-family:var(--font-mono);
  font-size:11.5px;
  line-height:1.8;
  color:#7f97a6;
}
.footer__index{min-width:0;}

/* 纸色索引时间线 */
.index-timeline{
  position:relative;
  background:var(--paper);
  color:var(--ink);
  border:1px solid var(--paper-edge);
  border-radius:var(--radius-l);
  box-shadow:var(--shadow-paper);
  padding:clamp(18px,2.6vw,30px);
}
.index-timeline__title{
  margin:0 0 14px;
  font-family:var(--font-mono);
  font-size:12px;
  font-weight:700;
  letter-spacing:.24em;
  color:#4a6d80;
}
.index-timeline__list{
  position:relative;
  margin:0;
  padding:0;
  list-style:none;
}
.index-timeline__list::before{
  content:"";
  position:absolute;
  left:4px;
  top:20px;
  bottom:20px;
  width:1px;
  background:repeating-linear-gradient(180deg,rgba(6,24,38,.35) 0 6px,transparent 6px 13px);
}
.index-timeline__item{
  position:relative;
  padding:12px 0 12px 26px;
  border-bottom:1px dashed rgba(6,24,38,.22);
}
.index-timeline__item:last-child{border-bottom:0;padding-bottom:0;}
.index-timeline__item::before{
  content:"";
  position:absolute;
  left:0;
  top:20px;
  width:9px;
  height:9px;
  border-radius:50%;
  background:var(--orange);
  box-shadow:0 0 0 3px rgba(255,154,77,.28);
}
.index-timeline__label{
  display:block;
  font-family:var(--font-mono);
  font-size:12.5px;
  font-weight:700;
  letter-spacing:.12em;
  color:#0c2b45;
}
.index-timeline__text{
  display:block;
  margin-top:2px;
  font-size:14px;
  line-height:1.7;
  color:#3c566b;
}
.index-timeline__link{
  display:inline-flex;
  margin-top:6px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:#0a5c66;
  text-decoration:none;
  border-bottom:1px solid rgba(10,92,102,.6);
  transition:color var(--dur) ease,border-color var(--dur) ease;
}
.index-timeline__link:hover{color:#b8621f;border-bottom-color:#b8621f;}

.footer__bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:14px 28px;
  padding-block:20px 28px;
  border-top:1px solid rgba(29,78,111,.55);
}
.footer__legal{
  display:flex;
  flex-wrap:wrap;
  gap:6px 20px;
  margin:0;
  padding:0;
  list-style:none;
  font-size:13px;
}
.footer__legal a{
  color:var(--mist);
  text-decoration:none;
  border-bottom:1px solid rgba(157,180,196,.4);
  transition:color var(--dur) ease,border-color var(--dur) ease;
}
.footer__legal a:hover{color:var(--cyan);border-bottom-color:var(--cyan);}
.footer__meta{
  margin:0;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:#7e94a3;
}

/* ---------- 阅读进度条 ---------- */
.scroll-progress{
  position:fixed;
  top:0;
  left:0;
  z-index:200;
  width:100%;
  height:2px;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan) 0%,#7ef0e4 45%,var(--orange) 100%);
  pointer-events:none;
  transition:transform 90ms linear;
}

/* ---------- 响应式 ---------- */
@media (max-width:1100px){
  .header-utility{display:none;}
  .site-nav__link{font-size:13.5px;padding:8px 8px;}
}
@media (max-width:1023px){
  .site-nav__link::before{display:none;}
  .site-nav__list{gap:2px;}
}
@media (max-width:899px){
  .site-nav{
    position:fixed;
    left:0;
    right:0;
    top:var(--header-h);
    z-index:118;
    display:none;
    margin:0;
    max-height:calc(100dvh - var(--header-h));
    overflow-y:auto;
    padding:16px clamp(16px,5vw,32px) 26px;
    background:linear-gradient(180deg,rgba(8,30,46,.99) 0%,rgba(4,16,26,.99) 100%);
    border-bottom:1px solid var(--edge);
    box-shadow:0 34px 60px -40px #000;
  }
  .site-nav[data-open]{
    display:block;
    animation:nav-drop 220ms ease both;
  }
  .site-nav__list{
    flex-direction:column;
    align-items:stretch;
    gap:0;
  }
  .site-nav__item{width:100%;}
  .site-nav__link{
    width:100%;
    padding:14px 8px;
    font-size:16px;
    border-radius:0;
    border-bottom:1px solid rgba(29,78,111,.45);
    color:#c6d6e0;
  }
  .site-nav__link:hover{background:rgba(29,78,111,.3);}
  .site-nav__link[aria-current="page"]{
    background:transparent;
    color:var(--cyan);
  }
  .site-nav__link[aria-current="page"]::after{
    left:auto;
    right:8px;
    top:50%;
    bottom:auto;
    width:6px;
    height:6px;
    border-radius:50%;
    transform:translateY(-50%);
  }
  .site-nav__actions{
    display:grid;
    gap:10px;
    margin-top:20px;
    padding-top:20px;
    border-top:1px solid rgba(29,78,111,.5);
  }
  .site-nav__actions .btn{width:100%;}
  .header-actions{display:none;}
  .nav-toggle{display:inline-flex;margin-inline-start:auto;}
  .footer__top{grid-template-columns:1fr;}
}
@media (max-width:640px){
  :root{--header-h:64px;}
  body{font-size:16px;}
  .brand__name{font-size:16px;}
  .brand__tagline{font-size:10px;letter-spacing:.14em;}
  .brand__glyph{width:32px;height:32px;font-size:14px;}
  .footer__bottom{flex-direction:column;align-items:flex-start;}
}

@keyframes nav-drop{
  from{opacity:0;transform:translateY(-8px);}
  to{opacity:1;transform:translateY(0);}
}

/* ---------- 减弱动效 ---------- */
@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-progress{transition:none;}
  .site-nav[data-open]{animation:none;}
}