*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:104px}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul,ol{padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
a{color:inherit}
:root{
--bt-ink:#0B1F33;
--bt-ink-2:#123A52;
--bt-ink-3:#07131F;
--bt-jade:#4FD1C5;
--bt-iris:#8B7CF6;
--bt-coral:#FF8A6B;
--bt-pearl:#F6F4EF;
--bt-mist:#DCE8EC;
--bt-slate:#5C6B7A;
--bt-gold:#D8C7A3;
--bt-line:rgba(11,31,51,.14);
--bt-line-soft:rgba(216,199,163,.22);
--bt-radius-s:10px;
--bt-radius-m:18px;
--bt-radius-organic:22px 6px 20px 8px;
--bt-shadow-1:0 1px 0 rgba(11,31,51,.05),0 18px 40px -28px rgba(7,19,31,.5);
--bt-shadow-2:0 26px 64px -34px rgba(7,19,31,.68);
--bt-max:1440px;
--bt-prose:720px;
--bt-font-display:"Noto Serif SC","Source Han Serif SC","Songti SC",Georgia,serif;
--bt-font-body:"Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
--bt-font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
--bt-ease:cubic-bezier(.22,1,.36,1);
--bt-gutter:clamp(16px,3.4vw,40px);
--bt-section-y:clamp(48px,7vw,96px);
}
body{
background:var(--bt-pearl);
color:var(--bt-ink);
font-family:var(--bt-font-body);
font-size:16px;
line-height:1.7;
letter-spacing:.01em;
-webkit-font-smoothing:antialiased;
text-rendering:optimizeLegibility;
}
h1,h2,h3,h4{font-family:var(--bt-font-display);font-weight:600;line-height:1.22;letter-spacing:.01em;color:var(--bt-ink)}
h1{font-weight:300;line-height:1.02;letter-spacing:.02em}
p{max-width:70ch}
strong{font-weight:600}
:where(a,button,summary,[tabindex]):focus-visible{
outline:3px solid var(--bt-jade);
outline-offset:3px;
border-radius:6px;
}
/* ---------- 跳过导航 ---------- */
.bt-skip{
position:fixed;top:10px;left:10px;z-index:300;
padding:11px 18px;border-radius:999px;
background:var(--bt-jade);color:var(--bt-ink);
font-size:14px;font-weight:600;text-decoration:none;
transform:translateY(-180%);
transition:transform .22s var(--bt-ease);
}
.bt-skip:focus{transform:none}
/* ---------- 头部 ---------- */
.bt-header{
position:sticky;top:0;z-index:90;color:var(--bt-pearl);
background:
radial-gradient(120% 190% at 6% -70%,rgba(79,209,197,.20),transparent 58%),
radial-gradient(86% 170% at 96% -60%,rgba(139,124,246,.18),transparent 62%),
linear-gradient(180deg,#0B1F33 0%,#0C2438 100%);
border-bottom:1px solid rgba(216,199,163,.18);
box-shadow:0 20px 44px -32px rgba(7,19,31,.95);
}
.bt-header__inner{
position:relative;
max-width:var(--bt-max);margin:0 auto;
min-height:84px;
padding:0 var(--bt-gutter);
display:flex;align-items:center;justify-content:space-between;
gap:clamp(14px,2.4vw,32px);
}
.bt-header__ruler{
position:absolute;left:0;right:0;bottom:2px;height:4px;
pointer-events:none;opacity:.42;
background:repeating-linear-gradient(90deg,var(--bt-gold) 0 1px,transparent 1px 10px);
-webkit-mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent);
mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent);
}
.bt-progress{position:absolute;left:0;right:0;bottom:0;height:2px;background:rgba(246,244,239,.08);overflow:hidden}
.bt-progress__bar{
display:block;width:100%;height:100%;
transform:scaleX(0);transform-origin:left center;
background:linear-gradient(90deg,var(--bt-jade),var(--bt-iris) 62%,var(--bt-coral));
transition:transform .12s linear;
}
/* 品牌 */
.bt-brand{display:flex;align-items:center;gap:clamp(12px,1.8vw,22px);min-width:0}
.bt-brand__link{
display:inline-flex;align-items:center;gap:12px;
padding:6px 4px;border-radius:12px;text-decoration:none;color:inherit;
}
.bt-brand__mark{
position:relative;flex:0 0 auto;width:34px;height:34px;border-radius:50%;
background:
radial-gradient(circle at 30% 24%,rgba(79,209,197,.95),rgba(79,209,197,0) 48%),
radial-gradient(circle at 74% 74%,rgba(139,124,246,.9),rgba(139,124,246,0) 54%),
conic-gradient(from 90deg,rgba(216,199,163,.85) 0 .9deg,transparent .9deg 36deg);
box-shadow:inset 0 0 0 1px rgba(216,199,163,.5);
}
.bt-brand__mark::after{
content:"";position:absolute;inset:32%;border-radius:50%;
background:radial-gradient(circle at 34% 28%,#FBF9F5,#C9D8DE 68%,#9FB6BE);
box-shadow:0 0 0 1px rgba(216,199,163,.55);
}
.bt-brand__text{display:flex;flex-direction:column;gap:2px;line-height:1.15;min-width:0}
.bt-brand__name{font-family:var(--bt-font-display);font-size:1.06rem;font-weight:600;letter-spacing:.08em}
.bt-brand__note{font-family:var(--bt-font-mono);font-size:10.5px;letter-spacing:.14em;color:rgba(246,244,239,.6)}
.bt-entry-status{
display:inline-flex;align-items:center;gap:8px;
padding:6px 13px;border-radius:999px;
border:1px solid rgba(79,209,197,.32);
background:rgba(79,209,197,.06);
font-family:var(--bt-font-mono);font-size:10.5px;letter-spacing:.12em;
color:rgba(246,244,239,.78);white-space:nowrap;
}
.bt-dot{width:6px;height:6px;border-radius:50%;background:var(--bt-coral);box-shadow:0 0 0 4px rgba(255,138,107,.16)}
/* 导航 */
.bt-nav{display:flex;align-items:center;gap:clamp(14px,2vw,26px);min-width:0}
.bt-nav__list{display:flex;align-items:center;gap:clamp(10px,1.5vw,20px)}
.bt-nav__link{
position:relative;display:inline-block;padding:9px 2px;
font-size:14px;letter-spacing:.05em;text-decoration:none;
color:rgba(246,244,239,.76);border-radius:6px;
transition:color .2s var(--bt-ease);
}
.bt-nav__link::after{
content:"";position:absolute;left:2px;right:2px;bottom:2px;height:1px;
background:linear-gradient(90deg,var(--bt-jade),var(--bt-iris));
transform:scaleX(0);transform-origin:left center;
transition:transform .28s var(--bt-ease);
}
.bt-nav__link:hover{color:var(--bt-pearl)}
.bt-nav__link:hover::after{transform:scaleX(1)}
.bt-nav__link[aria-current="page"]{color:var(--bt-pearl)}
.bt-nav__link[aria-current="page"]::after{transform:scaleX(1);height:2px}
.bt-nav__link[aria-current="page"]::before{
content:"";position:absolute;top:50%;left:-9px;
width:4px;height:4px;margin-top:-2px;border-radius:50%;
background:var(--bt-coral);
}
.bt-nav__cta{flex:0 0 auto}
/* 移动按钮 */
.bt-nav-toggle{
display:none;align-items:center;gap:10px;
padding:9px 14px;border-radius:12px;cursor:pointer;
background:rgba(246,244,239,.06);
border:1px solid rgba(216,199,163,.3);
color:var(--bt-pearl);
font-family:var(--bt-font-mono);font-size:11px;letter-spacing:.16em;
transition:background-color .2s var(--bt-ease),border-color .2s var(--bt-ease);
}
.bt-nav-toggle:hover{background:rgba(79,209,197,.14);border-color:rgba(79,209,197,.5)}
.bt-nav-toggle__bars{display:inline-grid;gap:4px;width:16px}
.bt-nav-toggle__bar{
display:block;height:1.5px;border-radius:2px;background:currentColor;
transition:transform .24s var(--bt-ease),opacity .18s linear;
}
.bt-nav-toggle[aria-expanded="true"] .bt-nav-toggle__bar:nth-child(1){transform:translateY(5.5px) rotate(45deg)}
.bt-nav-toggle[aria-expanded="true"] .bt-nav-toggle__bar:nth-child(2){opacity:0}
.bt-nav-toggle[aria-expanded="true"] .bt-nav-toggle__bar:nth-child(3){transform:translateY(-5.5px) rotate(-45deg)}
/* ---------- 页脚 ---------- */
.bt-footer{
position:relative;overflow:hidden;color:var(--bt-pearl);
background:
radial-gradient(90% 130% at 4% 0%,rgba(79,209,197,.16),transparent 56%),
radial-gradient(76% 130% at 100% 0%,rgba(139,124,246,.16),transparent 58%),
linear-gradient(180deg,#123A52 0%,#0B1F33 62%,#07131F 100%);
border-top:1px solid rgba(216,199,163,.22);
}
.bt-footer::before{
content:"";position:absolute;left:0;right:0;top:0;height:6px;opacity:.35;
background:repeating-linear-gradient(90deg,var(--bt-gold) 0 1px,transparent 1px 12px);
-webkit-mask-image:linear-gradient(90deg,transparent,#000 10%,#000 90%,transparent);
mask-image:linear-gradient(90deg,transparent,#000 10%,#000 90%,transparent);
}
.bt-footer__inner{
position:relative;max-width:var(--bt-max);margin:0 auto;
padding:clamp(44px,6vw,76px) var(--bt-gutter) 26px;
}
.bt-footer__top{
display:grid;
grid-template-columns:minmax(0,1.25fr) minmax(0,1fr) minmax(0,.95fr) minmax(0,.85fr);
gap:clamp(24px,3.6vw,52px);
}
.bt-footer__mark{
display:block;width:30px;height:30px;margin-bottom:14px;border-radius:50%;
background:
radial-gradient(circle at 30% 24%,rgba(79,209,197,.95),rgba(79,209,197,0) 48%),
radial-gradient(circle at 72% 72%,rgba(139,124,246,.9),rgba(139,124,246,0) 54%),
conic-gradient(from 90deg,rgba(216,199,163,.85) 0 .9deg,transparent .9deg 36deg);
box-shadow:inset 0 0 0 1px rgba(216,199,163,.45);
}
.bt-footer__name{
font-family:var(--bt-font-display);font-weight:600;
font-size:clamp(1.3rem,2.2vw,1.65rem);letter-spacing:.08em;
margin-bottom:10px;
}
.bt-footer__tagline{font-size:14px;line-height:1.78;color:rgba(246,244,239,.72);max-width:34ch}
.bt-footer__meta{
margin-top:14px;font-family:var(--bt-font-mono);font-size:11px;letter-spacing:.12em;
color:rgba(216,199,163,.8);
}
.bt-footer__title{
margin-bottom:16px;font-family:var(--bt-font-mono);font-weight:400;
font-size:11px;letter-spacing:.2em;color:rgba(216,199,163,.92);
}
.bt-footer__title--wide{display:block;margin-bottom:16px}
.bt-footer__list{display:grid;gap:11px}
.bt-footer__link{
display:inline-block;font-size:14px;text-decoration:none;
color:rgba(246,244,239,.74);
border-bottom:1px solid transparent;
transition:color .2s var(--bt-ease),border-color .2s var(--bt-ease);
}
.bt-footer__link:hover{color:var(--bt-jade);border-bottom-color:rgba(79,209,197,.55)}
.bt-footer__contact{
margin-top:clamp(28px,4vw,48px);
padding:clamp(18px,2.6vw,26px) clamp(18px,3vw,30px);
border:1px solid rgba(216,199,163,.2);
border-radius:var(--bt-radius-m);
background:rgba(246,244,239,.045);
}
.bt-footer__lines{
display:grid;grid-template-columns:repeat(auto-fit,minmax(238px,1fr));
gap:14px clamp(20px,3vw,40px);
}
.bt-footer__line{display:flex;flex-wrap:wrap;align-items:baseline;gap:6px 12px;min-width:0;max-width:none}
.bt-footer__label{flex:0 0 auto;font-family:var(--bt-font-mono);font-size:10.5px;letter-spacing:.16em;color:rgba(246,244,239,.5)}
.bt-footer__value{min-width:0;font-size:14px;color:rgba(246,244,239,.9);word-break:break-word}
.bt-copy{
flex:0 0 auto;cursor:pointer;
padding:4px 10px;border-radius:999px;
font-family:var(--bt-font-mono);font-size:10.5px;letter-spacing:.14em;
color:rgba(246,244,239,.85);
border:1px solid rgba(79,209,197,.34);
background:rgba(79,209,197,.08);
transition:background-color .2s var(--bt-ease),border-color .2s var(--bt-ease),color .2s var(--bt-ease);
}
.bt-copy:hover{border-color:var(--bt-jade);background:rgba(79,209,197,.2);color:#fff}
.bt-copy[data-copied]{border-color:var(--bt-coral);color:var(--bt-coral);background:rgba(255,138,107,.12)}
.bt-footer__bottom{
display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
gap:14px 24px;margin-top:clamp(24px,3.6vw,42px);padding-top:20px;
border-top:1px solid rgba(246,244,239,.12);
font-size:12.5px;color:rgba(246,244,239,.6);
}
.bt-footer__copy{font-family:var(--bt-font-mono);font-size:11.5px;letter-spacing:.08em;max-width:none}
.bt-footer__legal{display:flex;flex-wrap:wrap;align-items:center;gap:10px 20px}
.bt-footer__legal a{
font-size:12.5px;text-decoration:none;color:rgba(246,244,239,.82);
border-bottom:1px solid rgba(79,209,197,.4);padding-bottom:1px;
transition:color .2s var(--bt-ease),border-color .2s var(--bt-ease);
}
.bt-footer__legal a:hover{color:var(--bt-jade);border-bottom-color:var(--bt-jade)}
/* ---------- 按钮 ---------- */
.bt-btn{
display:inline-flex;align-items:center;justify-content:center;gap:8px;
padding:12px 22px;border-radius:999px;border:1px solid transparent;
font-family:var(--bt-font-body);font-size:14px;font-weight:600;letter-spacing:.04em;
text-decoration:none;cursor:pointer;background:transparent;
transition:transform .2s var(--bt-ease),box-shadow .26s var(--bt-ease),background-color .2s var(--bt-ease),color .2s var(--bt-ease),border-color .2s var(--bt-ease);
}
.bt-btn--entry{
color:var(--bt-ink-3);
background:linear-gradient(135deg,#4FD1C5 0%,#7FE3DA 52%,#B7E9F5 100%);
box-shadow:0 12px 28px -16px rgba(79,209,197,.95),inset 0 0 0 1px rgba(255,255,255,.45);
}
.bt-btn--entry:hover{
transform:translateY(-1px);
box-shadow:0 18px 38px -18px rgba(79,209,197,.95),0 0 0 1px rgba(139,124,246,.55),0 0 0 4px rgba(79,209,197,.14);
}
.bt-btn--primary{background:var(--bt-ink);color:var(--bt-pearl);border-color:rgba(216,199,163,.32)}
.bt-btn--primary:hover{background:var(--bt-ink-2);transform:translateY(-1px);box-shadow:var(--bt-shadow-1)}
.bt-btn--ghost{border-color:rgba(11,31,51,.28);color:var(--bt-ink)}
.bt-btn--ghost:hover{border-color:var(--bt-jade);background:rgba(79,209,197,.1);color:var(--bt-ink-2)}
.bt-btn--quiet{border-color:rgba(246,244,239,.28);color:var(--bt-pearl)}
.bt-btn--quiet:hover{border-color:var(--bt-jade);background:rgba(79,209,197,.12);color:#fff}
.bt-btn--mini{padding:7px 14px;font-size:12px}
.bt-btn--block{width:100%}
/* ---------- 容器 / 排版 ---------- */
.bt-container{width:100%;max-width:var(--bt-max);margin-inline:auto;padding-inline:var(--bt-gutter)}
.bt-container--narrow{max-width:1120px}
.bt-prose{
max-width:var(--bt-prose);
font-size:clamp(15.5px,1.1vw,17.5px);
line-height:1.78;color:var(--bt-ink-2);
}
.bt-prose > * + *{margin-top:1.05em}
.bt-prose h2,.bt-prose h3{color:var(--bt-ink);line-height:1.34}
.bt-prose h2{font-size:clamp(1.4rem,2.2vw,1.9rem);margin-top:1.8em}
.bt-prose h3{font-size:clamp(1.15rem,1.7vw,1.35rem);margin-top:1.5em}
.bt-prose a{text-decoration:underline;text-decoration-color:rgba(79,209,197,.85);text-underline-offset:3px}
.bt-prose ul,.bt-prose ol{padding-left:1.3em;list-style:revert}
.bt-prose li + li{margin-top:.45em}
.bt-prose blockquote{border-left:2px solid var(--bt-jade);padding-left:1em;color:var(--bt-slate)}
.bt-prose--ink{color:rgba(246,244,239,.84)}
.bt-prose--ink h2,.bt-prose--ink h3,.bt-prose--ink strong{color:var(--bt-pearl)}
/* ---------- 栅格 ---------- */
.bt-grid{display:grid;gap:clamp(18px,3vw,32px)}
.bt-grid--12{grid-template-columns:repeat(12,minmax(0,1fr))}
.bt-grid--split{grid-template-columns:minmax(0,1.35fr) minmax(0,.9fr)}
/* ---------- 章节 ---------- */
.bt-section{padding-block:var(--bt-section-y);position:relative}
.bt-section--light{background:var(--bt-mist)}
.bt-section--ink{
color:var(--bt-pearl);
background:
radial-gradient(80% 120% at 8% 0%,rgba(79,209,197,.14),transparent 58%),
linear-gradient(172deg,#0B1F33 0%,#123A52 68%,#0B1F33 100%);
}
.bt-section__head{display:grid;gap:12px;max-width:62ch;margin-bottom:clamp(24px,4vw,44px)}
.bt-kicker{
display:inline-flex;align-items:center;gap:10px;
font-family:var(--bt-font-mono);font-size:11.5px;letter-spacing:.2em;
color:var(--bt-slate);
}
.bt-kicker::before{content:"";width:22px;height:1px;background:linear-gradient(90deg,var(--bt-jade),transparent)}
.bt-section__title{font-size:clamp(2rem,4vw,3.4rem);line-height:1.14}
.bt-section__lede{margin:0;font-size:clamp(15px,1.4vw,17px);color:var(--bt-slate);max-width:60ch}
.bt-section--ink .bt-kicker{color:rgba(216,199,163,.9)}
.bt-section--ink .bt-section__title{color:var(--bt-pearl)}
.bt-section--ink .bt-section__lede{color:rgba(246,244,239,.72)}
/* ---------- 面板 ---------- */
.bt-panel{
position:relative;
background:var(--bt-pearl);
border:1px solid var(--bt-line);
border-radius:var(--bt-radius-m);
padding:clamp(20px,3vw,36px);
box-shadow:var(--bt-shadow-1);
}
.bt-panel--light{background:var(--bt-mist);border-color:rgba(11,31,51,.08)}
.bt-panel--ink{
color:var(--bt-pearl);
background:linear-gradient(160deg,#0B1F33,#123A52);
border-color:rgba(216,199,163,.2);
box-shadow:var(--bt-shadow-2);
}
.bt-panel--stack{
box-shadow:
14px 14px 0 -6px rgba(18,58,82,.10),
22px 22px 0 -12px rgba(79,209,197,.18),
var(--bt-shadow-1);
}
/* ---------- 标签 ---------- */
.bt-tag{
display:inline-flex;align-items:center;gap:6px;
padding:4px 11px;border-radius:999px;
font-family:var(--bt-font-mono);font-size:11px;letter-spacing:.1em;
color:var(--bt-ink-2);background:rgba(220,232,236,.7);
border:1px solid rgba(11,31,51,.16);
}
.bt-tag--jade{color:#08302F;background:rgba(79,209,197,.24);border-color:rgba(79,209,197,.5)}
.bt-tag--iris{color:#241C52;background:rgba(139,124,246,.22);border-color:rgba(139,124,246,.5)}
.bt-tag--coral{color:#5C2216;background:rgba(255,138,107,.26);border-color:rgba(255,138,107,.55)}
.bt-tag--ghost{color:rgba(246,244,239,.82);background:transparent;border-color:rgba(246,244,239,.3)}
/* ---------- 面包屑 ---------- */
.bt-crumbs{
display:flex;flex-wrap:wrap;align-items:center;gap:8px;
font-family:var(--bt-font-mono);font-size:11.5px;letter-spacing:.1em;
color:var(--bt-slate);
}
.bt-crumbs__item{display:inline-flex;align-items:center;gap:8px}
.bt-crumbs__link{
text-decoration:none;color:var(--bt-ink-2);
border-bottom:1px solid rgba(11,31,51,.2);padding-bottom:1px;
}
.bt-crumbs__link:hover{color:var(--bt-ink);border-bottom-color:var(--bt-jade)}
.bt-crumbs__sep{color:rgba(92,107,122,.55)}
.bt-crumbs [aria-current="page"]{color:var(--bt-ink)}
.bt-crumbs--dark{color:rgba(246,244,239,.6)}
.bt-crumbs--dark .bt-crumbs__link{color:rgba(246,244,239,.85);border-bottom-color:rgba(79,209,197,.45)}
.bt-crumbs--dark [aria-current="page"]{color:var(--bt-pearl)}
/* ---------- 索引列表 ---------- */
.bt-index{display:grid}
.bt-index__item{
display:grid;grid-template-columns:auto 1fr auto;
gap:14px;align-items:baseline;
padding:13px 0;border-bottom:1px solid var(--bt-line);
font-size:15px;
}
.bt-index__num{font-family:var(--bt-font-mono);font-size:11.5px;letter-spacing:.12em;color:var(--bt-slate)}
.bt-index__link{text-decoration:none;color:var(--bt-ink-2);transition:color .2s var(--bt-ease)}
.bt-index__link:hover{color:var(--bt-ink)}
.bt-section--ink .bt-index__item{border-bottom-color:rgba(246,244,239,.14)}
.bt-section--ink .bt-index__link{color:rgba(246,244,239,.85)}
/* ---------- 时间轴 ---------- */
.bt-timeline{position:relative;display:grid;gap:clamp(18px,3vw,30px);padding-left:2px}
.bt-timeline::before{
content:"";position:absolute;top:8px;bottom:8px;left:8px;width:1px;
background:linear-gradient(180deg,rgba(79,209,197,.6),rgba(139,124,246,.45),rgba(216,199,163,.18));
}
.bt-timeline__item{position:relative;padding-left:34px}
.bt-timeline__item::before{
content:"";position:absolute;left:0;top:5px;width:17px;height:17px;border-radius:50%;
background:radial-gradient(circle,var(--bt-jade) 0 3px,transparent 3.5px),var(--bt-pearl);
border:1px solid rgba(79,209,197,.6);
box-shadow:0 0 0 4px rgba(79,209,197,.12);
}
.bt-timeline__item[data-state="latest"]::before{
background:radial-gradient(circle,var(--bt-coral) 0 3.5px,transparent 4px),var(--bt-pearl);
border-color:rgba(255,138,107,.8);
box-shadow:0 0 0 4px rgba(255,138,107,.16);
}
.bt-timeline__week{
display:inline-block;margin-bottom:6px;
font-family:var(--bt-font-mono);font-size:11.5px;letter-spacing:.14em;color:var(--bt-slate);
}
.bt-timeline__body{margin:0;font-size:15px;line-height:1.74;color:var(--bt-ink-2);max-width:56ch}
.bt-timeline--ink::before{background:linear-gradient(180deg,rgba(79,209,197,.75),rgba(139,124,246,.5),rgba(216,199,163,.22))}
.bt-timeline--ink .bt-timeline__week{color:rgba(216,199,163,.85)}
.bt-timeline--ink .bt-timeline__body{color:rgba(246,244,239,.8)}
.bt-timeline--ink .bt-timeline__item::before{
background:radial-gradient(circle,var(--bt-jade) 0 3px,transparent 3.5px),#0B1F33;
box-shadow:0 0 0 4px rgba(79,209,197,.16);
}
/* ---------- 图片容器 ---------- */
.bt-media{
position:relative;overflow:hidden;isolation:isolate;
aspect-ratio:16/10;
border-radius:var(--bt-radius-organic);
background:linear-gradient(150deg,#0B1F33,#123A52 55%,#1C4A5E);
box-shadow:var(--bt-shadow-1);
}
.bt-media--wide{aspect-ratio:21/9}
.bt-media--portrait{aspect-ratio:3/4}
.bt-media--square{aspect-ratio:1/1}
.bt-media__img{width:100%;height:100%;object-fit:cover}
.bt-media__veil{
position:absolute;inset:0;pointer-events:none;mix-blend-mode:screen;
background:
radial-gradient(80% 120% at 18% 0%,rgba(79,209,197,.3),transparent 60%),
radial-gradient(70% 96% at 100% 100%,rgba(139,124,246,.26),transparent 62%);
}
.bt-media__caption{
position:absolute;left:16px;right:16px;bottom:14px;
font-family:var(--bt-font-mono);font-size:11px;letter-spacing:.12em;
color:rgba(246,244,239,.88);
text-shadow:0 1px 10px rgba(7,19,31,.65);
}
/* ---------- 轻提示 ---------- */
.bt-toast{
position:fixed;left:50%;bottom:24px;z-index:300;
max-width:calc(100vw - 32px);
padding:11px 20px;border-radius:999px;
background:rgba(7,19,31,.95);color:var(--bt-pearl);
border:1px solid rgba(79,209,197,.4);
font-family:var(--bt-font-mono);font-size:12px;letter-spacing:.1em;text-align:center;
box-shadow:var(--bt-shadow-2);
opacity:0;visibility:hidden;transform:translate(-50%,14px);
transition:opacity .24s var(--bt-ease),transform .24s var(--bt-ease),visibility .24s;
}
.bt-toast.is-visible{opacity:1;visibility:visible;transform:translate(-50%,0)}
/* ---------- 滚动显现 ---------- */
.bt-js [data-reveal]{
opacity:0;transform:translateY(12px);
transition:opacity .42s var(--bt-ease),transform .42s var(--bt-ease);
}
.bt-js [data-reveal].is-revealed{opacity:1;transform:none}
/* ---------- 平板 ---------- */
@media (max-width:1080px){
.bt-footer__top{grid-template-columns:repeat(3,minmax(0,1fr));gap:32px}
.bt-footer__brand{grid-column:1/-1}
.bt-footer__tagline{max-width:48ch}
.bt-grid--12{grid-template-columns:repeat(8,minmax(0,1fr))}
.bt-grid--split{grid-template-columns:minmax(0,1fr);}
.bt-nav__link{font-size:13.5px}
}
/* ---------- 移动导航 ---------- */
@media (max-width:960px){
.bt-header__inner{min-height:68px;gap:12px}
.bt-nav-toggle{display:inline-flex}
.bt-entry-status{display:none}
.bt-nav{
position:absolute;top:100%;left:0;right:0;
display:none;flex-direction:column;align-items:stretch;gap:0;
padding:10px var(--bt-gutter) 24px;
background:linear-gradient(180deg,#0C2438 0%,#0A1B2C 88%);
border-bottom:1px solid rgba(216,199,163,.24);
box-shadow:var(--bt-shadow-2);
}
.bt-nav[data-open]{display:flex;animation:bt-nav-in .26s var(--bt-ease) both}
.bt-nav__list{flex-direction:column;align-items:stretch;gap:0;width:100%}
.bt-nav__item{border-bottom:1px solid rgba(246,244,239,.09)}
.bt-nav__link{display:block;padding:15px 2px;font-size:15px;border-radius:4px}
.bt-nav__link::after{display:none}
.bt-nav__link:hover{color:var(--bt-jade)}
.bt-nav__link[aria-current="page"]{color:var(--bt-jade)}
.bt-nav__link[aria-current="page"]::before{display:none}
.bt-nav__cta{
display:flex;width:100%;margin-top:20px;
justify-content:center;padding:14px 22px;font-size:15px;
}
}
@keyframes bt-nav-in{
from{opacity:0;transform:translateY(-10px)}
to{opacity:1;transform:none}
}
/* ---------- 手机 ---------- */
@media (max-width:720px){
html{scroll-padding-top:84px}
.bt-brand__note{display:none}
.bt-brand__mark{width:30px;height:30px}
.bt-footer__top{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px 24px}
.bt-footer__lines{grid-template-columns:minmax(0,1fr)}
.bt-footer__bottom{flex-direction:column;align-items:flex-start}
.bt-grid--12{grid-template-columns:repeat(4,minmax(0,1fr))}
.bt-panel--stack{box-shadow:8px 8px 0 -4px rgba(18,58,82,.1),14px 14px 0 -9px rgba(79,209,197,.18),var(--bt-shadow-1)}
.bt-prose{font-size:16px}
}
@media (max-width:460px){
.bt-nav-toggle__label{display:none}
.bt-nav-toggle{padding:9px 11px}
}
/* ---------- 可访问性与减弱动效 ---------- */
@media (prefers-reduced-motion:reduce){
html{scroll-behavior:auto}
*,*::before,*::after{
animation-duration:.001ms !important;
animation-iteration-count:1 !important;
transition-duration:.001ms !important;
transition-delay:0ms !important;
}
.bt-js [data-reveal]{opacity:1 !important;transform:none !important}
.bt-progress__bar{transition:none}
.bt-skip{transition:none}
}
@media print{
.bt-header,.bt-footer,.bt-progress,.bt-toast,.bt-nav-toggle{display:none !important}
}