/* ============ 小鸟棋牌 · 共享样式 /assets/site.css ============ */

:root{
  --feather-teal:#0F8B7A;
  --feather-teal-deep:#075E54;
  --table-gold:#D9A441;
  --table-gold-soft:#F2D28B;
  --ink-blue:#10243E;
  --neon-violet:#7B4DFF;
  --paper:#F7F4EC;
  --mist:#E8EEEB;
  --line:#C9D6D2;
  --text:#1C2B2A;

  --fs-12:0.75rem;
  --fs-14:0.875rem;
  --fs-16:1rem;
  --fs-20:1.25rem;
  --fs-28:1.75rem;
  --fs-40:2.5rem;
  --fs-64:4rem;
  --fs-88:5.5rem;

  --wrap:1180px;
  --gutter:clamp(16px,4vw,32px);
  --radius-sm:3px;
  --radius:6px;

  --shadow-1:0 1px 0 rgba(16,36,62,.05), 0 10px 26px -20px rgba(16,36,62,.5);
  --shadow-2:0 22px 48px -28px rgba(16,36,62,.6);

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

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  background:var(--paper);
  color:var(--text);
  font-family:var(--font-body);
  font-size:var(--fs-16);
  line-height:1.75;
  letter-spacing:.01em;
  font-feature-settings:"kern" 1;
}
h1,h2,h3,h4,h5{
  font-family:var(--font-heading);
  color:var(--ink-blue);
  line-height:1.22;
  margin:0 0 .55em;
  font-weight:700;
  letter-spacing:-.01em;
}
h1{font-size:clamp(2rem,5vw,var(--fs-40))}
h2{font-size:var(--fs-28)}
h3{font-size:var(--fs-20)}
p{margin:0 0 1em}
ul,ol{margin:0 0 1em;padding-left:1.25em}
img{max-width:100%;display:block;height:auto}
a{color:var(--feather-teal-deep);text-decoration:none}
a:hover{color:var(--feather-teal)}
button{font:inherit}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
::selection{background:var(--table-gold-soft);color:var(--ink-blue)}
:focus-visible{outline:3px solid var(--neon-violet);outline-offset:3px;border-radius:2px}
.site-header :focus-visible,.site-footer :focus-visible{outline-color:var(--table-gold-soft)}

/* ---------- layout ---------- */
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
.skip-link{
  position:absolute;left:-9999px;top:0;z-index:200;
  background:var(--table-gold);color:#20170a;
  padding:.7em 1.1em;border-radius:0 0 var(--radius) 0;
  font-size:var(--fs-14);font-weight:600;letter-spacing:.04em;text-decoration:none;
}
.skip-link:focus{left:0}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5em;
  padding:.68em 1.15em;border-radius:var(--radius-sm);
  font-size:var(--fs-14);font-weight:600;letter-spacing:.04em;
  text-decoration:none;border:1px solid transparent;white-space:nowrap;cursor:pointer;
  transition:transform .18s ease,background-color .18s ease,color .18s ease,border-color .18s ease;
}
.btn-gold{background:var(--table-gold);color:#20170a;border-color:rgba(32,23,10,.14)}
.btn-gold:hover{background:var(--table-gold-soft);color:#20170a;transform:translateY(-2px)}
.btn-ghost{background:transparent;color:var(--paper);border-color:rgba(247,244,236,.45)}
.btn-ghost:hover{color:var(--table-gold-soft);border-color:var(--table-gold-soft);transform:translateY(-2px)}
.btn-teal{background:var(--feather-teal);color:#fff;border-color:rgba(255,255,255,.14)}
.btn-teal:hover{background:var(--feather-teal-deep);color:#fff;transform:translateY(-2px)}
.btn-line{background:transparent;color:var(--feather-teal-deep);border-color:var(--line)}
.btn-line:hover{border-color:var(--feather-teal);background:rgba(15,139,122,.08)}

/* ---------- read progress ---------- */
.read-progress{
  position:fixed;inset:0 0 auto 0;height:3px;z-index:90;
  background:rgba(16,36,62,.12);pointer-events:none;
}
.read-progress-bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--feather-teal) 0%,var(--table-gold) 68%,var(--neon-violet) 100%);
}

/* ---------- header ---------- */
.site-header{position:relative;z-index:60}
.header-rail{
  position:relative;color:var(--paper);
  background:
    linear-gradient(102deg,rgba(15,139,122,.42) 0 26%,rgba(15,139,122,0) 26.3%),
    linear-gradient(98deg,#10243E 0%,#0C1D33 52%,#075E54 100%);
}
.rail-inner{display:flex;align-items:center;gap:clamp(14px,3vw,40px);padding:13px 0}
.brand{display:inline-flex;align-items:center;gap:12px;text-decoration:none;color:inherit;flex:0 0 auto}
.brand-mark{
  display:grid;place-items:center;width:38px;height:38px;flex:0 0 38px;
  font-family:var(--font-heading);font-size:var(--fs-20);font-weight:700;line-height:1;
  color:#0b1a12;
  background:linear-gradient(135deg,var(--table-gold) 0%,var(--table-gold-soft) 100%);
  clip-path:polygon(0 0,100% 0,100% 70%,74% 100%,0 100%);
}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{font-family:var(--font-heading);font-size:var(--fs-20);font-weight:700;letter-spacing:.08em}
.brand-sub{font-size:var(--fs-12);letter-spacing:.18em;opacity:.7;margin-top:2px}
.rail-note{
  flex:1 1 auto;margin:0;padding-left:16px;
  border-left:1px solid rgba(247,244,236,.24);
  font-size:var(--fs-12);letter-spacing:.06em;color:rgba(247,244,236,.72);
}
.rail-actions{display:flex;gap:10px;flex:0 0 auto}
.nav-toggle{
  display:none;align-items:center;gap:10px;
  background:rgba(247,244,236,.08);border:1px solid rgba(247,244,236,.34);
  color:var(--paper);padding:.55em .9em;border-radius:var(--radius-sm);
  font-size:var(--fs-12);letter-spacing:.16em;cursor:pointer;
}
.nav-toggle-bars{position:relative;display:block;width:18px;height:2px;background:currentColor}
.nav-toggle-bars::before,.nav-toggle-bars::after{
  content:"";position:absolute;left:0;width:18px;height:2px;background:currentColor;
  transition:transform .2s ease,top .2s ease;
}
.nav-toggle-bars::before{top:-6px}
.nav-toggle-bars::after{top:6px}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before{top:0;transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after{top:0;transform:rotate(-45deg)}

.header-nav{
  position:relative;display:block;
  background:var(--paper);
  border-bottom:1px solid var(--line);
}
.header-nav::before{
  content:"";position:absolute;inset:0 0 auto 0;height:3px;
  background:linear-gradient(90deg,
    var(--table-gold) 0 16%,
    var(--feather-teal) 16% 58%,
    var(--neon-violet) 58% 70%,
    rgba(16,36,62,.10) 70% 100%);
}
.nav-inner{display:flex;align-items:stretch;justify-content:space-between;gap:20px}
.nav-list{display:flex;flex-wrap:wrap;list-style:none;margin:0;padding:0;gap:2px}
.nav-link{
  display:block;padding:15px 18px;
  font-size:var(--fs-14);font-weight:500;letter-spacing:.06em;
  color:var(--ink-blue);text-decoration:none;
  border-bottom:3px solid transparent;
  transition:color .18s ease,border-color .18s ease,background-color .18s ease;
}
.nav-link:hover{
  color:var(--feather-teal-deep);
  border-bottom-color:var(--table-gold);
  background:linear-gradient(180deg,rgba(217,164,65,0),rgba(217,164,65,.16));
}
.nav-link[aria-current="page"]{
  color:var(--feather-teal-deep);font-weight:700;
  border-bottom-color:var(--feather-teal);
  background:linear-gradient(180deg,rgba(15,139,122,0),rgba(15,139,122,.12));
}
.nav-meta{
  margin:0;align-self:center;
  font-family:var(--font-mono);font-size:var(--fs-12);letter-spacing:.16em;
  color:rgba(28,43,42,.5);
}
.nav-quick{display:none}

/* ---------- footer ---------- */
.site-footer{
  position:relative;margin-top:clamp(32px,6vw,72px);
  color:rgba(247,244,236,.84);
  background:
    linear-gradient(115deg,rgba(217,164,65,.12) 0%,rgba(217,164,65,0) 36%),
    linear-gradient(200deg,var(--feather-teal-deep) 0%,var(--ink-blue) 60%,#0A1626 100%);
}
.site-footer::before{
  content:"";display:block;height:3px;
  background:linear-gradient(90deg,
    var(--table-gold) 0 12%,
    var(--feather-teal) 12% 46%,
    var(--neon-violet) 46% 58%,
    rgba(247,244,236,.14) 58% 100%);
}
.site-footer a{color:rgba(247,244,236,.86);text-decoration:none;border-bottom:1px solid transparent}
.site-footer a:hover{color:var(--table-gold-soft);border-bottom-color:currentColor}
.footer-grid{
  display:grid;grid-template-columns:1.5fr 1fr 1fr 1.35fr;
  gap:clamp(24px,4vw,56px);padding:clamp(36px,5vw,60px) 0 clamp(28px,4vw,44px);
}
.footer-brand .brand-name{color:var(--paper)}
.footer-brand .brand-sub{letter-spacing:.12em;opacity:.62}
.footer-note{margin:16px 0 0;max-width:32ch;font-size:var(--fs-14);line-height:1.7;color:rgba(247,244,236,.72)}
.footer-cta{margin:20px 0 0}
.footer-col-title{
  font-family:var(--font-body);font-size:var(--fs-12);font-weight:700;
  letter-spacing:.2em;color:var(--table-gold-soft);
  margin:0 0 14px;text-transform:uppercase;
}
.footer-list{list-style:none;margin:0;padding:0;display:grid;gap:9px;font-size:var(--fs-14)}
.footer-contact{font-size:var(--fs-14)}
.footer-contact li{display:grid;gap:2px}
.footer-label{font-size:var(--fs-12);letter-spacing:.14em;color:rgba(247,244,236,.5)}
.footer-legal-bar{
  display:flex;flex-wrap:wrap;gap:8px 24px;justify-content:space-between;align-items:center;
  padding:18px 0 28px;border-top:1px solid rgba(247,244,236,.16);
}
.footer-meta{margin:0;font-size:var(--fs-12);letter-spacing:.06em;color:rgba(247,244,236,.62)}

/* ---------- 通用内容组件 ---------- */
.section{padding:clamp(38px,6vw,84px) 0;position:relative}
.section-head{display:grid;gap:10px;margin-bottom:clamp(20px,3vw,32px)}
.section-num{
  margin:0;font-family:var(--font-mono);font-size:var(--fs-14);
  letter-spacing:.28em;color:var(--feather-teal);
}
.section-title{margin:0;font-size:clamp(1.6rem,3.6vw,var(--fs-40))}
.section-desc{margin:0;max-width:62ch;color:rgba(28,43,42,.78)}
.lede{font-family:var(--font-heading);font-size:var(--fs-20);line-height:1.7;max-width:56ch;color:var(--ink-blue)}

.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  margin:0 0 18px;padding:20px 0 0;
  font-size:var(--fs-12);letter-spacing:.08em;color:rgba(28,43,42,.6);
}
.breadcrumb a{color:inherit;text-decoration:none}
.breadcrumb a:hover{color:var(--feather-teal-deep)}
.breadcrumb-sep{color:var(--line)}

.grid{display:grid;gap:clamp(16px,2.4vw,28px)}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}

.card{
  position:relative;background:#fff;border:1px solid var(--line);
  border-radius:var(--radius);padding:clamp(18px,2.2vw,26px);
  box-shadow:var(--shadow-1);
  transition:transform .22s ease,box-shadow .22s ease,border-color .22s ease;
}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-2);border-color:rgba(15,139,122,.42)}
.card-accent::before{
  content:"";position:absolute;inset:0 auto 0 0;width:3px;
  background:linear-gradient(180deg,var(--table-gold),var(--feather-teal));
  border-radius:var(--radius) 0 0 var(--radius);
}

.badge{
  display:inline-flex;align-items:center;gap:.4em;
  padding:.28em .7em;border-radius:999px;
  font-size:var(--fs-12);font-weight:600;letter-spacing:.06em;
  background:rgba(15,139,122,.12);color:var(--feather-teal-deep);
  border:1px solid rgba(15,139,122,.24);
}
.badge-gold{background:rgba(217,164,65,.18);color:#6b4c11;border-color:rgba(217,164,65,.42)}
.badge-violet{background:rgba(123,77,255,.12);color:#4a2bb0;border-color:rgba(123,77,255,.3)}
.tag{
  display:inline-block;font-family:var(--font-mono);font-size:var(--fs-12);
  padding:.2em .55em;border:1px solid var(--line);border-radius:var(--radius-sm);
  color:rgba(28,43,42,.72);
}

.prose{max-width:68ch}
.prose h2{font-size:var(--fs-28);margin-top:1.7em}
.prose h3{font-size:var(--fs-20);margin-top:1.4em}
.prose li{margin:.35em 0}
.prose a{color:var(--feather-teal-deep);border-bottom:1px solid rgba(15,139,122,.4)}
.prose a:hover{border-bottom-color:var(--feather-teal)}

.toc{list-style:none;margin:0;padding:0;display:grid;gap:4px;font-size:var(--fs-14)}
.toc-link{
  display:block;padding:8px 10px;border-left:2px solid var(--line);
  color:rgba(28,43,42,.72);text-decoration:none;
  transition:color .18s ease,border-color .18s ease,background-color .18s ease;
}
.toc-link:hover{color:var(--feather-teal-deep);border-left-color:var(--feather-teal)}
.toc-link.is-current{
  color:var(--ink-blue);font-weight:600;
  border-left-color:var(--table-gold);
  background:rgba(217,164,65,.1);
}

.fold{
  border:1px solid var(--line);border-radius:var(--radius);
  background:#fff;margin:0 0 12px;overflow:hidden;
}
.fold summary{
  display:flex;justify-content:space-between;align-items:center;gap:12px;
  padding:16px 18px;cursor:pointer;list-style:none;
  font-weight:600;color:var(--ink-blue);
}
.fold summary::-webkit-details-marker{display:none}
.fold summary::after{
  content:"+";font-family:var(--font-mono);font-size:var(--fs-20);
  line-height:1;color:var(--feather-teal);
}
.fold[open] summary::after{content:"–"}
.fold-body{padding:0 18px 18px;color:rgba(28,43,42,.82)}

/* ---------- 响应式图片容器 ---------- */
.figure{
  position:relative;margin:0;overflow:hidden;
  border:1px solid var(--line);border-radius:var(--radius);background:var(--mist);
}
.figure-frame{display:block;aspect-ratio:16/9;width:100%}
.figure-frame.is-square{aspect-ratio:1/1}
.figure-frame.is-portrait{aspect-ratio:4/5}
.figure-frame.is-wide{aspect-ratio:21/9}
.figure img{width:100%;height:100%;object-fit:cover;display:block}
.figure-caption{
  margin:0;padding:9px 12px;background:#fff;border-top:1px solid var(--line);
  font-size:var(--fs-12);color:rgba(28,43,42,.66);
}
.figure-tag{position:absolute;top:12px;left:12px;z-index:2}

/* ---------- 滚动显现 ---------- */
html.js [data-reveal]{
  opacity:0;transform:translateY(14px);
  transition:opacity .5s ease,transform .5s ease;
}
html.js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 平板 ---------- */
@media (max-width:1080px){
  .grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:1.4fr 1fr 1fr;row-gap:32px}
  .footer-grid .footer-col:last-child{grid-column:1 / -1}
}
@media (max-width:880px){
  .rail-note,.rail-actions{display:none}
  .nav-toggle{display:inline-flex;margin-left:auto}
  .header-nav{display:none;border-bottom:1px solid var(--line)}
  .header-nav[data-open]{display:block;animation:navDrop .22s ease-out}
  .nav-inner{flex-direction:column;align-items:stretch;gap:0;padding-bottom:10px}
  .nav-list{flex-direction:column;gap:0}
  .nav-link{
    padding:15px 4px;font-size:var(--fs-16);
    border-bottom:1px solid var(--line);
  }
  .nav-link:hover{border-bottom-color:var(--line);background:linear-gradient(90deg,rgba(217,164,65,.12),transparent)}
  .nav-link[aria-current="page"]{
    border-bottom-color:var(--line);
    background:linear-gradient(90deg,rgba(15,139,122,.16),transparent);
    box-shadow:inset 3px 0 0 var(--feather-teal);
    padding-left:12px;
  }
  .nav-meta{display:none}
  .nav-quick{
    display:grid;grid-template-columns:1fr 1fr;gap:10px;padding:16px 0 6px;
  }
  @keyframes navDrop{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:none}}
}
@media (max-width:640px){
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .footer-grid .footer-col:last-child{grid-column:auto}
  .footer-legal-bar{justify-content:flex-start}
  :root{--fs-88:3.4rem;--fs-64:2.6rem;--fs-40:2rem}
}

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