/* ==========================================================
   OAVE ・ oave.cn 品牌站样式
   零依赖、无外链资源；配色：墨黑 / 波青 / 赤陶
   ========================================================== */
:root{
  --ink:#101B24;
  --ink-soft:#1B2C38;
  --paper:#F6F5F2;
  --paper-2:#EBE9E3;
  --wave:#1B6A8A;
  --wave-soft:#2E8AAE;
  --accent:#B4552D;
  --line:#D5D2C9;
  --muted:#6B6A64;
  --white:#FFFEFB;

  --serif:"Noto Serif SC","Noto Serif CJK SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --sans:"Noto Sans SC","Noto Sans CJK SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --mono:ui-monospace,"SFMono-Regular","Cascadia Mono",Menlo,Consolas,monospace;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{
  background:var(--paper);color:var(--ink);
  font-family:var(--sans);font-size:17px;line-height:1.9;
  -webkit-font-smoothing:antialiased;
}
img,svg{max-width:100%}
a{color:inherit}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *{animation:none!important;transition:none!important}
}

/* ================= 顶栏：桌面一行 / 移动两行 ================= */
.topbar{
  position:sticky;top:0;z-index:60;
  background:rgba(246,245,242,.94);
  backdrop-filter:saturate(150%) blur(10px);
  border-bottom:1px solid var(--line);
}
.topbar-inner{
  max-width:1180px;margin:0 auto;padding:10px 20px;
  display:flex;align-items:center;gap:14px;flex-wrap:wrap;
}
.brandmark{
  display:flex;align-items:center;gap:10px;
  text-decoration:none;color:var(--ink);flex:none;
}
.brandmark svg{width:30px;height:30px;flex:none;display:block}
.brandmark b{
  font-family:var(--mono);font-size:17px;font-weight:700;
  letter-spacing:.16em;
}
.brandmark i{
  font-style:normal;font-size:11px;color:var(--muted);
  letter-spacing:.1em;font-family:var(--mono);
  border-left:1px solid var(--line);padding-left:10px;margin-left:2px;
}
.topnav{
  display:flex;align-items:center;gap:4px;flex-wrap:wrap;
  margin-left:auto;order:3;width:100%;
}
.topnav a{
  display:inline-flex;align-items:center;justify-content:center;
  text-decoration:none;font-size:13.5px;color:var(--ink-soft);
  padding:6px 11px;border-radius:7px;
  background:rgba(16,27,36,.03);
  transition:background .18s,color .18s;
  white-space:nowrap;line-height:1.4;
}
.topnav a:hover,.topnav a:focus-visible{background:rgba(27,106,138,.1);color:var(--wave)}
.cta{
  display:inline-flex;align-items:center;justify-content:center;
  text-decoration:none;font-size:13.5px;font-weight:500;
  background:var(--ink);color:var(--paper);
  padding:8px 16px;border-radius:7px;flex:none;line-height:1.4;
  transition:background .18s;
}
.cta:hover{background:var(--wave)}
.topbar .cta{margin-left:auto;order:2}

@media(min-width:1080px){
  .topbar-inner{flex-wrap:nowrap;gap:20px}
  .topnav{order:2;width:auto;margin-left:auto;flex-wrap:nowrap}
  .topbar .cta{order:3;margin-left:4px}
}

/* ================= HERO ================= */
.hero{
  background:var(--ink);color:var(--paper);
  position:relative;overflow:hidden;
  border-bottom:1px solid #0A141B;
}
.hero::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:
    radial-gradient(680px 320px at 82% 12%,rgba(27,106,138,.30),transparent 70%),
    radial-gradient(520px 260px at 8% 92%,rgba(180,85,45,.16),transparent 72%);
}
.hero-grid{
  position:relative;z-index:1;
  max-width:1180px;margin:0 auto;padding:64px 20px 56px;
  display:grid;grid-template-columns:1fr;gap:38px;align-items:center;
}
@media(min-width:980px){.hero-grid{grid-template-columns:1.02fr .98fr;gap:52px;padding:84px 20px 76px}}
.eyebrow{
  font-family:var(--mono);font-size:11.5px;letter-spacing:.24em;
  color:var(--wave-soft);margin-bottom:20px;display:flex;align-items:center;gap:10px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;flex:none}
.hero h1{
  font-family:var(--serif);font-size:clamp(34px,5.4vw,54px);
  line-height:1.24;font-weight:700;letter-spacing:.01em;margin-bottom:20px;
}
.hero h1 em{font-style:normal;color:var(--paper);border-bottom:3px solid var(--accent);padding-bottom:2px}
.lede{
  font-size:16.5px;line-height:1.95;color:#C4D0D9;max-width:34em;
}
.lede strong{color:var(--white);font-weight:500}
.hero-facts{
  margin-top:30px;display:grid;grid-template-columns:1fr;
  border-top:1px solid #2A3D4B;
}
.fact{
  display:flex;align-items:baseline;justify-content:space-between;gap:16px;
  padding:9px 0;border-bottom:1px solid #22323E;
}
.fact dt{
  font-size:11.5px;color:#7B8C99;letter-spacing:.1em;
  font-family:var(--mono);white-space:nowrap;
}
.fact dd{
  font-family:var(--mono);font-size:13.5px;color:var(--paper);
  letter-spacing:.03em;text-align:right;
}
.fact dd em{font-style:normal;color:#E0A276}

.logo-stage{
  background:var(--white);border-radius:16px;
  padding:clamp(24px,4vw,44px);
  box-shadow:0 18px 50px rgba(0,0,0,.28);
}
.logo-stage svg{width:100%;height:auto;display:block}
.logo-cap{
  margin-top:16px;padding-top:14px;border-top:1px solid var(--paper-2);
  font-family:var(--mono);font-size:11px;letter-spacing:.12em;
  color:var(--muted);display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;
}

/* ================= 区块 ================= */
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}
.sec{padding:64px 0 8px;border-top:1px solid var(--line);margin-top:56px}
.sec:first-of-type{border-top:none;margin-top:0}
.sec-head{max-width:44em;margin-bottom:34px}
.kicker{
  font-family:var(--mono);font-size:11px;letter-spacing:.2em;color:var(--wave);
  margin-bottom:12px;
}
.sec h2{
  font-family:var(--serif);font-size:clamp(26px,3.6vw,34px);
  font-weight:700;line-height:1.34;margin-bottom:14px;
}
.sec .sub{font-size:16px;color:var(--muted);line-height:1.9}
.sec p{margin-bottom:1.1em;text-align:justify;text-justify:inter-ideograph}
.sec p strong{font-weight:500;background:linear-gradient(transparent 64%,rgba(180,85,45,.18) 64%)}

/* 卡片网格 */
.cards{display:grid;grid-template-columns:1fr;gap:16px;margin:26px 0 36px}
@media(min-width:640px){.cards.two{grid-template-columns:1fr 1fr}}
@media(min-width:920px){.cards.three{grid-template-columns:repeat(3,1fr)}}
.card{
  background:var(--white);border:1px solid var(--line);border-radius:12px;
  padding:22px 22px 20px;
}
.card h3{
  font-family:var(--sans);font-size:15px;font-weight:700;
  margin-bottom:8px;letter-spacing:.01em;
}
.card p{font-size:14.5px;line-height:1.85;color:#3F4A53;margin:0}
.card .tag{
  display:inline-block;font-family:var(--mono);font-size:10.5px;
  letter-spacing:.1em;color:var(--wave);border:1px solid rgba(27,106,138,.3);
  border-radius:999px;padding:2px 9px;margin-bottom:10px;
}

/* 四字母 */
.letters{display:grid;grid-template-columns:1fr;gap:14px;margin:28px 0 34px}
@media(min-width:560px){.letters{grid-template-columns:1fr 1fr}}
@media(min-width:980px){.letters{grid-template-columns:repeat(4,1fr)}}
.letter{
  background:var(--ink);color:var(--paper);border-radius:12px;
  padding:20px 18px 18px;position:relative;overflow:hidden;
}
.letter .L{
  font-family:var(--mono);font-size:44px;font-weight:700;line-height:1;
  color:var(--white);letter-spacing:.02em;
}
.letter .L span{color:var(--accent)}
.letter .cn{
  font-family:var(--serif);font-size:15px;margin:8px 0 10px;
  color:#E3D9CE;letter-spacing:.08em;
}
.letter ul{list-style:none;display:flex;flex-direction:column;gap:5px}
.letter li{
  font-family:var(--mono);font-size:11.5px;color:#9FB2BF;
  letter-spacing:.02em;line-height:1.6;
}
.letter li b{color:var(--paper);font-weight:500}

/* 表格 */
.tbl{margin:26px 0 30px}
.tbl-title{
  font-family:var(--mono);font-size:11px;letter-spacing:.14em;
  color:var(--muted);margin-bottom:8px;
}
.tbl-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border-top:2px solid var(--ink)}
table{width:100%;border-collapse:collapse;font-size:14px;min-width:520px}
th,td{
  text-align:left;padding:11px 12px;border-bottom:1px solid var(--line);
  vertical-align:top;line-height:1.72;
}
th{
  font-family:var(--mono);font-size:11px;letter-spacing:.08em;
  color:var(--muted);font-weight:500;background:var(--paper-2);white-space:nowrap;
}
td.mono{font-family:var(--mono);font-size:13px;white-space:nowrap}
.tbl-note{font-size:12.5px;color:var(--muted);margin-top:10px;line-height:1.8}

/* 色板 */
.palette{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;margin:24px 0 30px}
@media(min-width:760px){.palette{grid-template-columns:repeat(5,1fr)}}
.sw{border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--white)}
.sw .chip{height:64px}
.sw .meta{padding:9px 10px 10px}
.sw .meta b{display:block;font-size:12px;font-weight:500}
.sw .meta code{font-family:var(--mono);font-size:10.5px;color:var(--muted)}

/* 合作方式 */
.coop{display:grid;grid-template-columns:1fr;gap:16px;margin:26px 0 34px}
@media(min-width:860px){.coop{grid-template-columns:repeat(3,1fr)}}
.coop-card{
  background:var(--white);border:1px solid var(--line);border-radius:12px;
  padding:24px 22px;display:flex;flex-direction:column;gap:10px;
}
.coop-card.pick{border:2px solid var(--wave)}
.coop-card h3{font-family:var(--serif);font-size:19px;font-weight:700}
.coop-card .lv{
  font-family:var(--mono);font-size:10.5px;letter-spacing:.14em;color:var(--wave);
}
.coop-card ul{list-style:none;display:flex;flex-direction:column;gap:7px;margin-top:2px}
.coop-card li{
  font-size:14px;line-height:1.7;color:#3F4A53;padding-left:16px;position:relative;
}
.coop-card li::before{
  content:"";position:absolute;left:0;top:10px;
  width:6px;height:6px;border-radius:50%;background:var(--wave);
}

/* 结语 */
.coda{
  background:var(--ink);color:var(--paper);border-radius:16px;
  padding:clamp(28px,5vw,52px);margin:60px 0 0;
}
.coda .q{
  font-family:var(--serif);font-size:clamp(21px,3.2vw,29px);line-height:1.6;
  margin-bottom:16px;
}
.coda .q em{font-style:normal;color:#E0A276}
.coda p{color:#B7C4CE;font-size:15px;margin:0;line-height:1.9}

/* 页脚 */
footer{
  margin-top:64px;border-top:1px solid var(--line);
  background:var(--paper-2);
}
.foot{
  max-width:1180px;margin:0 auto;padding:38px 20px 30px;
  display:grid;grid-template-columns:1fr;gap:22px;
}
@media(min-width:760px){.foot{grid-template-columns:1.4fr 1fr 1fr}}
.foot h4{
  font-family:var(--mono);font-size:10.5px;letter-spacing:.16em;
  color:var(--muted);margin-bottom:10px;font-weight:500;
}
.foot p,.foot a{font-size:13.5px;line-height:1.85;color:#3F4A53;text-decoration:none}
.foot a{border-bottom:1px solid rgba(27,106,138,.35)}
.foot a:hover{color:var(--wave)}
.foot-brand{display:flex;align-items:center;gap:12px;margin-bottom:12px}
.foot-brand svg{width:34px;height:34px}
.foot-brand b{font-family:var(--mono);font-size:15px;letter-spacing:.16em}
.foot-bar{
  border-top:1px solid var(--line);
  max-width:1180px;margin:0 auto;padding:14px 20px 26px;
  font-family:var(--mono);font-size:11px;letter-spacing:.06em;color:var(--muted);
  display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;
}

/* 打印 */
@media print{
  .topbar,.cta{display:none}
  body{background:#fff;font-size:11.5pt;line-height:1.75}
  .hero{background:#fff;color:var(--ink);border:none}
  .hero::after{display:none}
  .hero h1 em{border-color:var(--ink)}
  .lede,.fact dd,.hero-facts .fact dd{color:var(--ink)}
  .hero-facts .fact{border-color:var(--line)}
  .letter{background:#fff;color:var(--ink);border:1px solid var(--line)}
  .letter .L,.letter .cn,.letter li b{color:var(--ink)}
  .letter li{color:#555}
  .coda{background:#fff;color:var(--ink);border:1px solid var(--line)}
  .coda p{color:#444}
  .sec{break-inside:avoid-page}
  .card,.coop-card{break-inside:avoid}
}