@import url('https://fonts.googleapis.com/css2?family=Fredoka:wght@400;500;600;700&family=Nunito:wght@300;400;500;600;700&display=swap');

:root{
  --bg:#ffffff;
  --soft:#f5f5f5;
  --ink:#1f1f1f;
  --ink-mid:#5a5a5a;
  --line:#e6e6e6;
  --r:4px;
  --e1:0 1px 2px rgba(31,31,31,.06),0 3px 8px rgba(31,31,31,.05);
  --e2:0 2px 5px rgba(31,31,31,.07),0 9px 20px rgba(31,31,31,.06);
  --e3:0 6px 14px rgba(31,31,31,.08),0 18px 36px rgba(31,31,31,.09);
  --e4:0 12px 26px rgba(31,31,31,.10),0 30px 60px rgba(31,31,31,.10);
  --dock:118px;
}

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

html{
  scroll-behavior:smooth;
  overflow-x:clip;
  -webkit-text-size-adjust:100%;
}

body{
  margin:0;
  background:
    radial-gradient(120% 80% at 50% -10%, #ffffff 0%, var(--soft) 55%, #eeeeee 100%) fixed;
  color:var(--ink);
  font:16px/1.75 'Nunito',system-ui,-apple-system,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  padding-bottom:calc(var(--dock) + 26px);
  letter-spacing:.01em;
}

h1,h2,h3,h4,.side-h,.foot-dl dt,.dock-name,.cta{font-family:'Fredoka','Nunito',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif}

a{color:var(--ink)}

p{margin:0 0 14px}
p:last-child{margin-bottom:0}

hr{border:0;border-top:1px solid var(--line);margin:16px 0}

img{max-width:100%;height:auto}

/* ---------- 骨架 ---------- */
.wrap{
  max-width:1140px;
  margin:0 auto;
  padding:18px 16px 0;
  position:relative;
}

.stage{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:18px;
  align-items:start;
}

main div{scroll-margin-top:14px}

/* ---------- 正文纸面 ---------- */
.paper{
  display:grid;
  gap:18px;
  position:relative;
  z-index:2;
  min-width:0;
}

.hero{
  position:relative;
  z-index:4;
  background:var(--bg);
  border-radius:var(--r);
  box-shadow:var(--e4);
  padding:clamp(22px,5vw,44px) clamp(18px,4vw,40px);
  min-height:45vh;
  display:flex;
  flex-direction:column;
  justify-content:center;
  align-items:center;
  text-align:center;
  gap:14px;
}

.hero::after{
  content:"";
  position:absolute;
  inset:auto 12% -8px 12%;
  height:22px;
  border-radius:50%;
  background:rgba(31,31,31,.10);
  filter:blur(14px);
  z-index:-1;
}

.hero h1{
  margin:0;
  font-size:clamp(26px,5.2vw,42px);
  line-height:1.24;
  font-weight:600;
  letter-spacing:.02em;
  max-width:22ch;
}

.hero-desc{
  margin:0;
  max-width:46ch;
  color:var(--ink-mid);
  font-size:17px;
  line-height:1.7;
}

.hero-fig{
  margin:8px 0 0;
  width:100%;
  max-width:520px;
  border-radius:var(--r);
  overflow:hidden;
  box-shadow:var(--e3);
  background:var(--soft);
}

.hero-fig img{
  display:block;
  width:100%;
  aspect-ratio:16/9;
  object-fit:cover;
  will-change:transform;
}

.paper div{
  position:relative;
  z-index:1;
  background:var(--bg);
  border-radius:var(--r);
  box-shadow:var(--e2);
  padding:22px clamp(16px,4vw,32px) 24px;
  transition:box-shadow .35s ease,transform .35s ease;
}

.paper div:hover{
  box-shadow:var(--e3);
  transform:translateY(-2px);
}

.paper h2{
  margin:0 0 10px;
  font-size:clamp(20px,3.2vw,27px);
  line-height:1.35;
  font-weight:600;
  letter-spacing:.01em;
}

.paper h2 + hr{
  border-top:2px solid var(--line);
  margin:-2px 0 16px;
}

.paper h3{
  margin:22px 0 8px;
  font-size:19px;
  line-height:1.4;
  font-weight:600;
}

.paper ul,.paper ol{margin:0 0 14px;padding-left:1.25em}
.paper li{margin:0 0 6px}

.paper blockquote{
  margin:0 0 14px;
  padding:12px 16px;
  background:var(--soft);
  border-left:3px solid var(--ink);
  border-radius:var(--r);
  color:var(--ink-mid);
}

.paper figure{margin:16px 0}
.paper figcaption{font-size:16px;color:var(--ink-mid);margin-top:6px}

.paper table{
  width:100%;
  border-collapse:collapse;
  font-size:16px;
  margin:0 0 14px;
}

.paper th,.paper td{
  border:1px solid var(--line);
  padding:9px 11px;
  text-align:left;
  vertical-align:top;
}

.paper thead th{background:var(--soft)}

.paper strong{font-weight:700}

/* ---------- 侧栏 ---------- */
.side{
  position:relative;
  z-index:3;
  background:var(--bg);
  border-radius:var(--r);
  box-shadow:var(--e2);
  padding:16px 14px 18px;
}

.side-h{
  margin:0 0 8px;
  font-size:19px;
  font-weight:600;
  letter-spacing:.02em;
}

.side hr{margin:0 0 10px}

.side-links{display:grid;gap:2px}

.side-links a{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:0 10px;
  border-left:2px solid transparent;
  border-radius:var(--r);
  color:var(--ink-mid);
  text-decoration:none;
  font-size:16px;
  transition:background .25s,color .25s,border-color .25s;
}

.side-links a:hover,
.side-links a:focus-visible{
  background:var(--soft);
  border-left-color:var(--ink);
  color:var(--ink);
}

/* ---------- 页脚 ---------- */
.foot{
  margin-top:34px;
  background:var(--bg);
  border-top:1px solid var(--line);
  box-shadow:0 -10px 30px rgba(31,31,31,.05);
  position:relative;
  z-index:5;
}

.foot-in{
  max-width:1140px;
  margin:0 auto;
  padding:26px 16px 6px;
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:22px;
}

.foot-brand{min-width:0}

.foot-logo{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  font-family:'Fredoka',system-ui,'Microsoft YaHei',sans-serif;
  font-size:19px;
  font-weight:600;
  text-decoration:none;
}

.mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-width:30px;
  height:30px;
  padding:0 6px;
  border-radius:var(--r);
  background:var(--ink);
  color:#fff;
  font-size:16px;
  box-shadow:var(--e1);
}

.mark-img{
  width:30px;
  height:30px;
  border-radius:var(--r);
  box-shadow:var(--e1);
}

.foot-desc{
  margin:6px 0 0;
  color:var(--ink-mid);
  font-size:16px;
  max-width:36ch;
}

.foot-nav{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:10px;
  min-width:0;
}

.foot-dl{margin:0}

.foot-dl dt{
  font-size:16px;
  font-weight:600;
  margin-bottom:4px;
  color:var(--ink);
}

.foot-dl dd{margin:0}

.foot-dl a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  color:var(--ink-mid);
  text-decoration:none;
  font-size:16px;
  line-height:1.4;
}

.foot-dl a:hover,
.foot-dl a:focus-visible{color:var(--ink);text-decoration:underline;text-underline-offset:3px}

.foot-base{
  border-top:1px solid var(--line);
  margin-top:16px;
  padding:14px 16px 18px;
  text-align:center;
  color:var(--ink-mid);
  font-size:16px;
}

.foot-base p{margin:0}

/* ---------- 底部固定条 ---------- */
.dock{
  position:fixed;
  left:0;
  right:0;
  bottom:0;
  z-index:60;
  padding:7px 12px calc(7px + env(safe-area-inset-bottom));
  background:rgba(255,255,255,.88);
  backdrop-filter:blur(14px) saturate(1.25);
  -webkit-backdrop-filter:blur(14px) saturate(1.25);
  border-top:1px solid var(--line);
  box-shadow:0 -10px 28px rgba(31,31,31,.10);
}

.dock-brand{
  display:inline-flex;
  align-items:center;
  gap:8px;
  min-height:40px;
  text-decoration:none;
}

.dock-name{
  font-size:17px;
  font-weight:600;
  letter-spacing:.02em;
}

.dock-row{
  display:flex;
  align-items:center;
  gap:10px;
  min-width:0;
}

.dock-links{
  display:flex;
  align-items:center;
  gap:4px;
  overflow-x:auto;
  scrollbar-width:none;
  flex:1 1 auto;
  min-width:0;
}

.dock-links::-webkit-scrollbar{display:none}

.dock-links a{
  flex:0 0 auto;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 11px;
  border-radius:var(--r);
  color:var(--ink-mid);
  text-decoration:none;
  font-size:16px;
  white-space:nowrap;
  transition:background .2s,color .2s;
}

.dock-links a:hover,
.dock-links a:focus-visible{background:var(--soft);color:var(--ink)}

.cta{
  flex:0 0 auto;
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 16px;
  border-radius:var(--r);
  background:var(--ink);
  color:#fff;
  text-decoration:none;
  font-size:16px;
  font-weight:600;
  white-space:nowrap;
  box-shadow:var(--e2);
  transition:transform .2s,box-shadow .2s;
}

.cta:hover,.cta:focus-visible{transform:translateY(-2px);box-shadow:var(--e3)}

/* ---------- 揭示动效 ---------- */
.js .hero,
.js .paper div,
.js .side,
.js .foot-dl{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .6s ease,transform .65s cubic-bezier(.22,.8,.24,1);
}

.js .on{opacity:1;transform:none}

/* ---------- 桌面 ---------- */
@media (min-width:760px){
  :root{--dock:126px}
  .foot-nav{gap:18px}
}

@media (min-width:1000px){
  .wrap{padding-top:26px}
  .stage{grid-template-columns:minmax(0,1fr) 284px;gap:24px}
  .side{position:sticky;top:18px}
  .foot-in{grid-template-columns:minmax(0,1fr) minmax(0,1.9fr);gap:34px;align-items:start}
  .dock{padding-left:max(16px,calc((100vw - 1140px) / 2))}
  .dock{padding-right:max(16px,calc((100vw - 1140px) / 2))}
}

@media (min-width:1180px){
  .hero{padding-top:52px;padding-bottom:52px}
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js .hero,
  .js .paper div,
  .js .side,
  .js .foot-dl{opacity:1;transform:none;transition:none}
  .paper div:hover,
  .cta:hover{transform:none}
}

button[aria-expanded]{min-width:44px;min-height:44px}