:root{
  --brand:#ff4d6d;
  --brand-2:#ff8fa3;
  --brand-3:#ffb3c1;
  --accent:#7c5cff;
  --accent-2:#4dd4ff;
  --bg:#ffffff;
  --bg-soft:#f7f8fa;
  --fg:#1f2328;
  --muted:#5b6570;
  --card:#f7f8fa;
  --line:#e6e8eb;
  --glass:rgba(255,255,255,.6);
  --glass-border:rgba(255,255,255,.7);
  --shadow:0 8px 30px rgba(31,35,40,.08);
  --shadow-hover:0 16px 44px rgba(255,77,109,.16);
  --radius:16px;
  --radius-sm:10px;
  --radius-pill:999px;
  --header-h:64px;
  --maxw:1100px;
}

@media (prefers-color-scheme: dark){
  :root{
    --bg:#0f1115;
    --bg-soft:#161a20;
    --fg:#e6e9ee;
    --muted:#9aa4b0;
    --card:#161a20;
    --line:#262b33;
    --glass:rgba(22,26,32,.55);
    --glass-border:rgba(255,255,255,.08);
    --shadow:0 8px 30px rgba(0,0,0,.45);
    --shadow-hover:0 16px 44px rgba(255,77,109,.24);
    --brand-3:#7a3b48;
  }
}

*{box-sizing:border-box}

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

body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  color:var(--fg);
  background:var(--bg);
  line-height:1.8;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
  transition:background .3s ease,color .3s ease;
}

a{
  color:var(--brand);
  text-decoration:none;
  transition:color .2s ease,opacity .2s ease;
}
a:hover{text-decoration:underline}
a:focus-visible{
  outline:2px solid var(--brand);
  outline-offset:3px;
  border-radius:4px;
}

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

h1,h2,h3,h4{
  line-height:1.35;
  letter-spacing:-.01em;
}

h1{font-size:clamp(26px,4.2vw,38px);margin:0 0 14px}
h2{font-size:clamp(21px,3vw,27px);margin:0 0 18px;position:relative;padding-left:16px}
h2::before{
  content:"";
  position:absolute;
  left:0;top:.15em;bottom:.15em;
  width:5px;
  border-radius:var(--radius-pill);
  background:linear-gradient(180deg,var(--brand),var(--accent));
}
h3{font-size:clamp(17px,2.2vw,20px);margin:22px 0 10px}
h4{font-size:16px;margin:16px 0 8px;color:var(--muted)}

p{margin:0 0 14px}

ul.plain{padding-left:20px;margin:0 0 14px}
ul.plain li{margin-bottom:8px}
ol{padding-left:22px}
ol li{margin-bottom:8px}

.wrap{
  width:100%;
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 20px;
}

/* ---------- Header ---------- */
header.site{
  position:sticky;
  top:0;
  z-index:100;
  background:var(--glass);
  -webkit-backdrop-filter:blur(16px) saturate(160%);
  backdrop-filter:blur(16px) saturate(160%);
  border-bottom:1px solid var(--line);
  transition:background .3s ease,border-color .3s ease;
}

.nav{
  display:flex;
  align-items:center;
  justify-content:space-between;
  height:var(--header-h);
  gap:16px;
}

.nav .brand{
  font-weight:800;
  font-size:20px;
  color:var(--brand);
  letter-spacing:-.02em;
  white-space:nowrap;
  background:linear-gradient(120deg,var(--brand),var(--accent));
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
  transition:transform .25s ease;
}
.nav .brand:hover{transform:scale(1.04);text-decoration:none}

.nav ul{
  display:flex;
  gap:6px;
  list-style:none;
  margin:0;
  padding:0;
  flex-wrap:nowrap;
}
.nav ul li a{
  display:inline-block;
  padding:8px 12px;
  border-radius:var(--radius-pill);
  color:var(--muted);
  font-size:15px;
  font-weight:500;
  transition:background .2s ease,color .2s ease,transform .2s ease;
  white-space:nowrap;
}
.nav ul li a:hover{
  color:var(--brand);
  background:rgba(255,77,109,.1);
  text-decoration:none;
  transform:translateY(-1px);
}

/* ---------- Breadcrumb ---------- */
nav[aria-label="面包屑"]{
  font-size:13px;
  color:var(--muted);
  padding:16px 0 0;
}
nav[aria-label="面包屑"] a{color:var(--brand)}

/* ---------- Hero ---------- */
.hero{
  position:relative;
  padding:64px 0 56px;
  background:linear-gradient(135deg,#fff0f3 0%,#ffe3ea 30%,#f3ecff 65%,#e8f7ff 100%);
  overflow:hidden;
  border-bottom:1px solid var(--line);
}
.hero::before,
.hero::after{
  content:"";
  position:absolute;
  border-radius:50%;
  filter:blur(60px);
  opacity:.55;
  pointer-events:none;
  animation:floatBlob 14s ease-in-out infinite;
}
.hero::before{
  width:420px;height:420px;
  background:radial-gradient(circle,var(--brand-2),transparent 70%);
  top:-140px;right:-80px;
}
.hero::after{
  width:360px;height:360px;
  background:radial-gradient(circle,var(--accent-2),transparent 70%);
  bottom:-160px;left:-60px;
  animation-delay:-7s;
}

@keyframes floatBlob{
  0%,100%{transform:translate(0,0) scale(1)}
  50%{transform:translate(24px,-24px) scale(1.08)}
}

.hero .wrap{position:relative;z-index:1}

.hero h1{
  background:linear-gradient(100deg,var(--fg) 40%,var(--brand) 100%);
  -webkit-background-clip:text;
  background-clip:text;
  -webkit-text-fill-color:transparent;
  animation:fadeUp .7s ease both;
}

.hero p{
  font-size:clamp(15px,1.8vw,17px);
  color:var(--muted);
  max-width:780px;
  animation:fadeUp .7s ease .1s both;
}

@media (prefers-color-scheme: dark){
  .hero{
    background:linear-gradient(135deg,#1a1216 0%,#1d1622 40%,#141b24 100%);
  }
  .hero h1{
    background:linear-gradient(100deg,var(--fg) 40%,var(--brand-2) 100%);
    -webkit-background-clip:text;
    background-clip:text;
    -webkit-text-fill-color:transparent;
  }
}

/* ---------- Buttons ---------- */
.btns{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
  margin-top:20px;
  animation:fadeUp .7s ease .2s both;
}

.btn{
  display:inline-block;
  padding:11px 22px;
  border-radius:var(--radius-pill);
  background:linear-gradient(120deg,var(--brand),#ff6b8a);
  color:#fff;
  font-weight:600;
  font-size:15px;
  box-shadow:0 6px 20px rgba(255,77,109,.32);
  transition:transform .22s ease,box-shadow .22s ease,filter .22s ease;
}
.btn:hover{
  text-decoration:none;
  transform:translateY(-2px);
  box-shadow:0 12px 28px rgba(255,77,109,.42);
  filter:brightness(1.05);
}
.btn:active{transform:translateY(0)}

.btn.ghost{
  background:transparent;
  color:var(--brand);
  border:1.5px solid var(--brand);
  box-shadow:none;
}
.btn.ghost:hover{
  background:rgba(255,77,109,.08);
  box-shadow:0 8px 22px rgba(255,77,109,.18);
}

/* ---------- Sections ---------- */
main{display:block}

section{
  padding:48px 0;
  border-bottom:1px solid var(--line);
  scroll-margin-top:calc(var(--header-h) + 12px);
}

section:last-of-type{border-bottom:none}

/* ---------- Cards ---------- */
.cards{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(260px,1fr));
  gap:18px;
  margin-bottom:8px;
}

.card{
  position:relative;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:20px;
  transition:transform .28s ease,box-shadow .28s ease,border-color .28s ease,background .3s ease;
  will-change:transform;
}
.card:hover{
  transform:translateY(-4px);
  box-shadow:var(--shadow-hover);
  border-color:rgba(255,77,109,.35);
}
.card h3{margin-top:0}
.card p:last-child{margin-bottom:0}

.card::after{
  content:"";
  position:absolute;
  inset:0;
  border-radius:inherit;
  background:linear-gradient(120deg,rgba(255,77,109,.06),rgba(124,92,255,.06));
  opacity:0;
  transition:opacity .28s ease;
  pointer-events:none;
}
.card:hover::after{opacity:1}

/* ---------- Meta ---------- */
.meta{
  font-size:13px;
  color:var(--muted);
}

/* ---------- FAQ ---------- */
.faq details{
  border:1px solid var(--line);
  border-radius:var(--radius-sm);
  padding:14px 18px;
  margin-bottom:10px;
  background:var(--card);
  transition:border-color .25s ease,box-shadow .25s ease,background .3s ease;
}
.faq details:hover{
  border-color:rgba(255,77,109,.35);
  box-shadow:0 6px 20px rgba(31,35,40,.06);
}
.faq details[open]{
  border-color:rgba(255,77,109,.4);
  box-shadow:0 8px 24px rgba(255,77,109,.08);
}
.faq summary{
  cursor:pointer;
  font-weight:600;
  list-style:none;
  position:relative;
  padding-right:26px;
  transition:color .2s ease;
}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{
  content:"+";
  position:absolute;
  right:0;top:50%;
  transform:translateY(-50%);
  font-size:20px;
  font-weight:400;
  color:var(--brand);
  transition:transform .25s ease;
}
.faq details[open] summary::after{
  content:"−";
  transform:translateY(-50%) rotate(180deg);
}
.faq summary:hover{color:var(--brand)}
.faq details p{margin:10px 0 0;color:var(--muted)}

/* ---------- Tables ---------- */
table{
  width:100%;
  border-collapse:collapse;
  margin:16px 0;
  border-radius:var(--radius-sm);
  overflow:hidden;
  font-size:15px;
  box-shadow:var(--shadow);
}
th,td{
  border:1px solid var(--line);
  padding:12px 14px;
  text-align:left;
  vertical-align:top;
}
th{
  background:var(--card);
  font-weight:700;
  color:var(--fg);
}
tbody tr{transition:background .2s ease}
tbody tr:hover{background:rgba(255,77,109,.05)}

/* ---------- Footer ---------- */
footer.site{
  background:#14161b;
  color:#c9d1d9;
  padding:44px 0 32px;
  font-size:14px;
  position:relative;
  overflow:hidden;
}
footer.site::before{
  content:"";
  position:absolute;
  top:0;left:0;right:0;
  height:3px;
  background:linear-gradient(90deg,var(--brand),var(--accent),var(--accent-2));
}
footer.site a{color:var(--brand-2)}
footer.site a:hover{color:#fff;text-decoration:none}
footer.site h3,
footer.site h4{
  color:#fff;
  border:none;
  padding:0;
}
footer.site h3{margin:0 0 10px;font-size:18px}
footer.site h4{margin:0 0 10px;font-size:15px}
footer.site p{margin:0 0 10px;color:#a9b3bd}
footer.site ul.plain{padding-left:0;list-style:none}
footer.site ul.plain li{margin-bottom:8px}

.footgrid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
  gap:28px;
}

footer.site #copyright,
footer.site #privacy,
footer.site #terms{
  font-size:13px;
  color:#8b95a1;
  line-height:1.7;
}

/* ---------- Scroll animation ---------- */
@keyframes fadeUp{
  from{opacity:0;transform:translateY(18px)}
  to{opacity:1;transform:translateY(0)}
}

@supports (animation-timeline: view()){
  section > .wrap,
  .card,
  .faq details,
  table{
    animation:fadeUp linear both;
    animation-timeline:view();
    animation-range:entry 0% entry 30%;
  }
}

/* Fallback reveal for browsers without scroll-driven animations */
@supports not (animation-timeline: view()){
  section > .wrap{animation:fadeUp .6s ease both}
}

/* ---------- Utility ---------- */
::selection{
  background:rgba(255,77,109,.25);
  color:var(--fg);
}

::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{
  background:linear-gradient(180deg,var(--brand-2),var(--brand));
  border-radius:var(--radius-pill);
  border:2px solid var(--bg);
}
::-webkit-scrollbar-thumb:hover{background:var(--brand)}

/* ---------- Responsive ---------- */
@media (max-width:920px){
  .nav ul{gap:2px}
  .nav ul li a{padding:7px 9px;font-size:14px}
}

@media (max-width:720px){
  .nav ul{display:none}
  .hero{padding:44px 0 40px}
  section{padding:36px 0}
  .cards{grid-template-columns:1fr;gap:14px}
  .footgrid{grid-template-columns:1fr;gap:22px}
  h2{padding-left:14px}
  table{font-size:14px}
  th,td{padding:10px}
  .wrap{padding:0 16px}
}

@media (max-width:420px){
  .btn{padding:10px 18px;font-size:14px}
  .hero{padding:36px 0 32px}
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce){
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
}

/* ---------- Print ---------- */
@media print{
  header.site,footer.site,.btns,.hero::before,.hero::after{display:none !important}
  body{background:#fff;color:#000}
  section{border:none;padding:16px 0}
  .card{border:1px solid #ccc;box-shadow:none}
  a{color:#000;text-decoration:underline}
}