/* ================= 基础重置 ================= */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:transparent}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit}

/* ================= 变量 ================= */
:root{
  color-scheme:dark;
  --by-ink:#0F2B24;
  --by-ink-deep:#0A1F1A;
  --by-panel:#163A31;
  --by-edge:#1F4A3F;
  --by-neon:#3DF5C6;
  --by-neon-soft:rgba(61,245,198,.14);
  --by-goal:#FF7A45;
  --by-concede:#4A9EFF;
  --by-text:#E8F2EE;
  --by-muted:#9BB3AA;
  --by-live:#FF5C5C;
  --by-font-display:"Barlow Condensed","Noto Sans SC",system-ui,sans-serif;
  --by-font-body:"Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --by-font-mono:"JetBrains Mono","Roboto Mono",SFMono-Regular,Consolas,monospace;
  --by-shell:1180px;
  --by-gap:clamp(1rem,2.4vw,1.9rem);
  --by-radius:14px;
  --by-shadow:0 22px 46px -26px rgba(0,0,0,.88);
}

/* ================= 全局排版 ================= */
body{
  min-height:100vh;
  font-family:var(--by-font-body);
  font-size:15px;
  line-height:1.7;
  color:var(--by-text);
  background:
    radial-gradient(120% 58% at 84% -8%,rgba(61,245,198,.10),transparent 62%),
    radial-gradient(90% 52% at 6% 14%,rgba(74,158,255,.09),transparent 60%),
    radial-gradient(70% 40% at 50% 108%,rgba(255,122,69,.07),transparent 65%),
    linear-gradient(180deg,#0F2B24 0%,#0C231D 46%,#0A1F1A 100%);
  background-attachment:fixed;
  background-color:var(--by-ink);
}
h1,h2,h3{font-family:var(--by-font-display);font-weight:700;letter-spacing:.01em;line-height:1.2}
h1{font-size:clamp(2.5rem,5vw,4rem)}
h2{font-size:clamp(1.75rem,3vw,2.35rem)}
h3{font-size:1.25rem;line-height:1.35}
p{max-width:74ch}
:focus-visible{outline:2px solid var(--by-neon);outline-offset:3px;border-radius:6px}

@media (prefers-reduced-motion:no-preference){
  html{scroll-behavior:smooth}
}

/* ================= 布局容器 ================= */
.by-container{
  width:100%;
  max-width:var(--by-shell);
  margin-inline:auto;
  padding-inline:clamp(1rem,3vw,2rem);
}
.by-grid{display:grid;gap:var(--by-gap)}
.by-grid--7-5{grid-template-columns:7fr 5fr}
.by-grid--8-4{grid-template-columns:8fr 4fr}
.by-grid--thirds{grid-template-columns:repeat(3,minmax(0,1fr))}

/* ================= 滚动进度 ================= */
.by-progress{
  position:fixed;
  top:0;left:0;
  width:100%;height:3px;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--by-neon),#7BFFDD 58%,var(--by-goal));
  box-shadow:0 0 14px rgba(61,245,198,.55);
  z-index:140;
  pointer-events:none;
}

/* ================= 跳转链接 ================= */
.by-skip{
  position:absolute;
  left:1rem;top:-120px;
  z-index:200;
  padding:.6rem 1.05rem;
  background:var(--by-neon);
  color:#06201A;
  font-weight:700;
  font-size:.85rem;
  text-decoration:none;
  border-radius:0 0 10px 10px;
  transition:top .2s ease;
}
.by-skip:focus{top:0}

/* ================= 页头 ================= */
.by-header{position:relative;z-index:80}

.by-header__rail{
  background:linear-gradient(180deg,rgba(10,31,26,.97),rgba(10,31,26,.82));
  border-bottom:1px solid var(--by-edge);
}
.by-header__inner{
  max-width:var(--by-shell);
  margin-inline:auto;
  padding:.8rem clamp(1rem,3vw,2rem);
  display:flex;
  align-items:center;
  gap:clamp(.7rem,2vw,1.5rem);
}

/* 品牌 */
.by-brand{
  flex:0 0 auto;
  display:flex;
  align-items:center;
  gap:.7rem;
  text-decoration:none;
  color:var(--by-text);
}
.by-brand__mark{
  width:40px;height:40px;
  flex:0 0 auto;
  display:grid;place-items:center;
  border:1px solid rgba(61,245,198,.75);
  border-radius:10px;
  font-family:var(--by-font-display);
  font-weight:700;
  font-size:1.35rem;
  line-height:1;
  color:var(--by-neon);
  background:linear-gradient(150deg,rgba(61,245,198,.20),rgba(61,245,198,0));
  box-shadow:0 0 20px -6px rgba(61,245,198,.7);
}
.by-brand__text{display:block}
.by-brand__name{
  display:block;
  font-family:var(--by-font-display);
  font-weight:700;
  font-size:1.2rem;
  letter-spacing:.06em;
  line-height:1.2;
}
.by-brand__sub{
  display:block;
  font-family:var(--by-font-mono);
  font-size:.65rem;
  letter-spacing:.1em;
  line-height:1.4;
  color:var(--by-muted);
}
.by-brand--stack{flex-direction:column;align-items:flex-start;gap:.7rem}

/* 搜索提示 */
.by-search{
  flex:1 1 auto;
  min-width:0;
  max-width:340px;
  margin-inline:auto;
  display:flex;
  align-items:center;
  gap:.55rem;
  padding:.5rem .9rem;
  border:1px dashed var(--by-edge);
  border-radius:10px;
  background:rgba(22,58,49,.5);
  color:var(--by-muted);
  font-size:.82rem;
  line-height:1.4;
}
.by-search__key{color:var(--by-neon);font-family:var(--by-font-mono);font-size:.95rem}
.by-search__text{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* 快捷入口 */
.by-quick{flex:0 0 auto;display:flex;align-items:center;gap:.5rem}

/* 通用按钮 */
.by-btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.4rem;
  padding:.52rem 1rem;
  border:1px solid transparent;
  border-radius:9px;
  font-size:.83rem;
  font-weight:600;
  letter-spacing:.04em;
  line-height:1.4;
  text-decoration:none;
  white-space:nowrap;
  transition:background .18s ease,border-color .18s ease,color .18s ease,box-shadow .18s ease;
}
.by-btn--ghost{
  border-color:var(--by-edge);
  background:rgba(31,74,63,.4);
  color:var(--by-text);
}
.by-btn--ghost:hover{border-color:rgba(61,245,198,.7);color:var(--by-neon);background:rgba(61,245,198,.08)}
.by-btn--solid{
  background:var(--by-neon);
  color:#06201A;
  font-weight:700;
  box-shadow:0 12px 28px -16px rgba(61,245,198,.95);
}
.by-btn--solid:hover{background:#7BFFDD}

/* 移动按钮 */
.by-navtoggle{
  display:none;
  align-items:center;
  gap:.55rem;
  padding:.55rem .8rem;
  border:1px solid var(--by-edge);
  border-radius:9px;
  background:rgba(31,74,63,.45);
  color:var(--by-text);
  font-size:.82rem;
  letter-spacing:.05em;
  line-height:1.4;
}
.by-navtoggle:hover{border-color:rgba(61,245,198,.7)}
.by-navtoggle__bars{
  display:block;
  width:16px;height:2px;
  border-radius:2px;
  background:var(--by-neon);
  box-shadow:0 -5px 0 var(--by-neon),0 5px 0 var(--by-neon);
}
.by-navtoggle__label{font-family:var(--by-font-mono);letter-spacing:.12em}

/* 栏目带 */
.by-header__strip{
  background:linear-gradient(90deg,rgba(22,58,49,.98),rgba(15,43,36,.88));
  border-bottom:1px solid var(--by-edge);
}
.by-header__stripinner{
  position:relative;
  max-width:var(--by-shell);
  margin-inline:auto;
  padding:.3rem clamp(1rem,3vw,2rem);
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
}
.by-nav__list{display:flex;flex-wrap:wrap;gap:.12rem}
.by-nav__link{
  position:relative;
  display:block;
  padding:.62rem .82rem;
  border-radius:8px;
  font-size:.88rem;
  letter-spacing:.03em;
  line-height:1.4;
  color:var(--by-muted);
  text-decoration:none;
  transition:color .18s ease,background .18s ease;
}
.by-nav__link:hover{color:var(--by-text);background:rgba(61,245,198,.09)}
.by-nav__link[aria-current="page"]{color:var(--by-neon)}
.by-nav__link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:.82rem;right:.82rem;bottom:.16rem;
  height:2px;
  border-radius:2px;
  background:var(--by-neon);
  box-shadow:0 0 10px rgba(61,245,198,.9);
}
.by-header__stamp{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  font-family:var(--by-font-mono);
  font-size:.7rem;
  letter-spacing:.09em;
  line-height:1.4;
  color:var(--by-muted);
  white-space:nowrap;
}
.by-dot{
  width:7px;height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--by-live);
  box-shadow:0 0 10px var(--by-live);
  animation:by-pulse 2.4s ease-in-out infinite;
}
@keyframes by-pulse{0%,100%{opacity:1}50%{opacity:.3}}

/* ================= 页脚 ================= */
.by-footer{
  position:relative;
  margin-top:clamp(3rem,7vw,6rem);
  background:linear-gradient(180deg,rgba(10,31,26,.55),#081814 62%);
  border-top:1px solid var(--by-edge);
  overflow:hidden;
}
.by-footer__glow{
  position:absolute;
  top:-48%;left:-12%;right:44%;bottom:58%;
  background:radial-gradient(closest-side,rgba(61,245,198,.16),transparent 72%);
  pointer-events:none;
}
.by-footer__grid{
  position:relative;
  display:grid;
  grid-template-columns:1.7fr 1fr 1fr 1fr;
  gap:clamp(1.5rem,3vw,2.6rem);
  padding-block:clamp(2.4rem,5vw,3.6rem) 2.2rem;
}
.by-footer__brand{display:flex;flex-direction:column;gap:1rem}
.by-footer__note{
  max-width:36ch;
  font-size:.82rem;
  line-height:1.8;
  color:var(--by-muted);
}
.by-footer__contact{display:grid;gap:.4rem;font-size:.82rem;color:var(--by-text)}
.by-footer__key{
  display:inline-block;
  min-width:3.2em;
  margin-right:.5rem;
  font-family:var(--by-font-mono);
  font-size:.68rem;
  letter-spacing:.14em;
  color:var(--by-neon);
}
.by-footer__title{
  margin-bottom:.9rem;
  font-family:var(--by-font-mono);
  font-size:.72rem;
  font-weight:600;
  letter-spacing:.18em;
  line-height:1.5;
  color:var(--by-neon);
}
.by-footer__list{display:grid;gap:.52rem}
.by-footer__link{
  font-size:.87rem;
  line-height:1.5;
  color:var(--by-muted);
  text-decoration:none;
  transition:color .18s ease,padding-left .18s ease;
}
.by-footer__link:hover{color:var(--by-text);padding-left:.24rem}
.by-footer__legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.5rem 1.6rem;
  padding-block:1.15rem;
  border-top:1px solid var(--by-edge);
  font-family:var(--by-font-mono);
  font-size:.76rem;
  letter-spacing:.05em;
  line-height:1.6;
  color:var(--by-muted);
}
.by-footer__copy,.by-footer__stamp{max-width:none}

/* ================= 面包屑 ================= */
.by-crumbs{padding-block:.4rem 0}
.by-crumbs__list{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.45rem;
  font-family:var(--by-font-mono);
  font-size:.72rem;
  letter-spacing:.1em;
  line-height:1.6;
  color:var(--by-muted);
}
.by-crumbs__link{color:var(--by-muted);text-decoration:none}
.by-crumbs__link:hover{color:var(--by-neon)}
.by-crumbs__sep{opacity:.45}

/* ================= 正文容器 ================= */
.by-prose{max-width:72ch;color:var(--by-text)}
.by-prose p{margin-bottom:1.1em}
.by-prose h2{margin:1.8em 0 .6em}
.by-prose h3{margin:1.5em 0 .5em;font-family:var(--by-font-body);font-weight:700}
.by-prose ul{display:grid;gap:.5rem;margin:0 0 1.2em;padding-left:1.1rem;list-style:disc}
.by-prose li::marker{color:var(--by-neon)}
.by-prose a{color:var(--by-neon);text-underline-offset:3px}

/* ================= 章节色带 ================= */
.by-band{
  display:flex;
  align-items:center;
  gap:.85rem;
  margin:clamp(2rem,5vw,3.4rem) 0 1.2rem;
}
.by-band__num{
  font-family:var(--by-font-mono);
  font-size:.78rem;
  letter-spacing:.2em;
  line-height:1.5;
  color:var(--by-neon);
}
.by-band__line{
  flex:1 1 auto;
  height:1px;
  background:linear-gradient(90deg,rgba(61,245,198,.85),rgba(61,245,198,0));
}

/* ================= 标签 ================= */
.by-tag{
  display:inline-flex;
  align-items:center;
  gap:.34rem;
  padding:.22rem .62rem;
  border:1px solid var(--by-edge);
  border-radius:999px;
  background:rgba(31,74,63,.45);
  font-family:var(--by-font-mono);
  font-size:.68rem;
  letter-spacing:.1em;
  line-height:1.6;
  color:var(--by-muted);
}
.by-tag--neon{color:var(--by-neon);border-color:rgba(61,245,198,.5);background:rgba(61,245,198,.08)}
.by-tag--goal{color:var(--by-goal);border-color:rgba(255,122,69,.45);background:rgba(255,122,69,.08)}
.by-tag--concede{color:var(--by-concede);border-color:rgba(74,158,255,.45);background:rgba(74,158,255,.08)}

/* ================= 说明牌 ================= */
.by-card{
  position:relative;
  padding:clamp(1rem,2vw,1.5rem);
  border:1px solid var(--by-edge);
  border-radius:var(--by-radius);
  background:linear-gradient(160deg,rgba(22,58,49,.94),rgba(15,43,36,.7));
  transition:transform .22s ease,border-color .22s ease,box-shadow .22s ease;
}
.by-card:hover{
  transform:translateY(-3px);
  border-color:rgba(61,245,198,.55);
  box-shadow:var(--by-shadow);
}

/* ================= 数据数字 ================= */
.by-num{
  font-family:var(--by-font-mono);
  font-weight:700;
  font-size:2.2em;
  line-height:1;
  letter-spacing:-.02em;
  color:var(--by-text);
  text-shadow:0 0 18px rgba(61,245,198,.35);
}

/* ================= 图片容器 ================= */
.by-media{
  position:relative;
  display:block;
  width:100%;
  overflow:hidden;
  border:1px solid var(--by-edge);
  border-radius:var(--by-radius);
  background:linear-gradient(140deg,#163A31,#0A1F1A);
}
.by-media > img{width:100%;height:100%;object-fit:cover}
.by-media--wide{aspect-ratio:16/9}
.by-media--tall{aspect-ratio:3/4}
.by-media--square{aspect-ratio:1/1}

/* ================= 滚动显现 ================= */
[data-reveal]{opacity:0;transform:translateY(8px);transition:opacity .5s ease,transform .5s ease}
[data-reveal].is-in{opacity:1;transform:none}

/* ================= 响应式 ================= */
@media (max-width:960px){
  .by-grid--7-5,.by-grid--8-4,.by-grid--thirds{grid-template-columns:1fr}

  .by-search{display:none}
  .by-navtoggle{display:inline-flex;margin-left:auto}

  .by-nav{
    display:none;
    position:absolute;
    left:0;right:0;top:100%;
    padding:.6rem clamp(1rem,3vw,2rem) 1rem;
    background:linear-gradient(180deg,#0F2B24,#0A1F1A);
    border-bottom:1px solid rgba(61,245,198,.6);
    box-shadow:0 34px 56px -34px #000;
    z-index:90;
  }
  .by-nav[data-open]{display:block}
  .by-nav__list{flex-direction:column;gap:0}
  .by-nav__link{
    padding:.85rem .55rem;
    font-size:.95rem;
    border-bottom:1px solid rgba(31,74,63,.7);
    border-radius:0;
  }
  .by-nav__link[aria-current="page"]::after{
    left:.55rem;right:auto;
    width:22px;bottom:.52rem;
  }
  .by-header__stamp{display:none}

  .by-footer__grid{grid-template-columns:1.6fr 1fr 1fr}
  .by-footer__brand{grid-column:1 / -1}
}

@media (max-width:720px){
  .by-quick{display:none}
  .by-navtoggle{margin-left:0}
  .by-header__inner{gap:1rem}
}

@media (max-width:640px){
  .by-footer__grid{grid-template-columns:1fr 1fr;gap:1.6rem}
  .by-footer__legal{flex-direction:column;align-items:flex-start}
}

@media (max-width:420px){
  .by-footer__grid{grid-template-columns:1fr}
  .by-brand__sub{font-size:.6rem;letter-spacing:.06em}
}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  [data-reveal]{opacity:1;transform:none}
}