/* 布局概念：左对齐的「航空信」。页面顶端一条红绿航空邮件斜纹，首屏是一只贴着信鸽邮票的信封，
   信封里装着 12 个助记词——这就是账号。其余版块安静、留白、单栏节奏，不做卡片堆砌。 */
:root{
  --paper:#F6F7F4;      /* 纸面，偏冷的米白 */
  --paper-2:#EDF0EC;    /* 第二层纸面 */
  --sky:#DCF1E6;        /* 取自 logo 的薄荷天色 */
  --ink:#13232F;        /* 墨 */
  --ink-2:#4F5D67;      /* 次级文字 */
  --line:#D5DBD6;       /* 细线 */
  --accent:#0C8A6B;     /* 信鸽绿，用于按钮与链接 */
  --accent-ink:#0A6E55; /* 绿上压深 */
  --accent-soft:#D9F0E6;
  --post-red:#C9432F;   /* 航空邮件红，只用于斜纹与邮戳 */
  --stamp:#FFFFFF;
  --focus:#1D6FD1;
  --display:'Noto Serif SC','Songti SC','STSong',serif;
  --body:'Noto Sans SC','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
}
@media (prefers-color-scheme: dark){
  :root{
    --paper:#0F1B22;--paper-2:#15232B;--sky:#143029;--ink:#EDF2EE;--ink-2:#A3B0B4;--line:#263840;
    --accent:#3AC49C;--accent-ink:#6FE0BF;--accent-soft:#17392F;--post-red:#E2604C;--stamp:#1B2A33;--focus:#7FB4FF;
    color-scheme:dark;
  }
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--body);font-size:17px;line-height:1.75;-webkit-font-smoothing:antialiased}
body::before{content:"";position:fixed;inset:0 0 auto;height:env(safe-area-inset-top,0px);z-index:10;background:var(--paper)}
img{max-width:100%;display:block}
a{color:var(--accent-ink);text-decoration-thickness:1px;text-underline-offset:3px}
:focus-visible{outline:2px solid var(--focus);outline-offset:3px;border-radius:4px}
h1,h2,h3{font-family:var(--display);font-weight:900;line-height:1.2;margin:0;text-wrap:balance;letter-spacing:.01em}
p{margin:0}
.wrap{max-width:1120px;margin:0 auto;padding-left:max(16px,env(safe-area-inset-left,0px));padding-right:max(16px,env(safe-area-inset-right,0px))}

/* 航空邮件斜纹：页面顶端唯一一条，信封边框再用一次 */
.airmail{height:7px;background:repeating-linear-gradient(135deg,var(--post-red) 0 16px,transparent 16px 32px,var(--accent) 32px 48px,transparent 48px 64px)}

/* 导航 */
.nav{position:sticky;top:env(safe-area-inset-top,0px);z-index:9;background:color-mix(in srgb,var(--paper) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:28px;height:64px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);font-weight:900;font-size:20px;color:var(--ink);text-decoration:none;white-space:nowrap;flex:none}
.brand img{width:32px;height:32px;border-radius:8px}
.brand small{font-family:var(--body);font-weight:400;font-size:13px;color:var(--ink-2);margin-left:2px}
.nav-links{display:flex;gap:24px;margin-left:auto}
.nav-links a{color:var(--ink);text-decoration:none;font-size:15px;font-weight:500}
.nav-links a:hover{color:var(--accent-ink)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:48px;padding:0 22px;border-radius:999px;font-weight:500;font-size:16px;text-decoration:none;border:1.5px solid transparent;cursor:pointer;font-family:var(--body);white-space:nowrap}
.btn-primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.btn-primary:hover{background:var(--accent-ink);border-color:var(--accent-ink)}
.btn-ghost{background:transparent;color:var(--ink);border-color:var(--line)}
.btn-ghost:hover{border-color:var(--ink)}
.btn-sm{height:40px;padding:0 18px;font-size:15px}
.nav .btn{margin-left:4px}

/* 首屏 */
.hero{padding-block:72px 64px;background:linear-gradient(180deg,var(--sky) 0%,var(--paper) 100%)}
.hero .wrap{display:grid;grid-template-columns:minmax(0,11fr) minmax(0,9fr);gap:56px;align-items:center}
.hero h1{font-size:clamp(38px,5.2vw,64px)}
.hero .lede{margin-top:22px;font-size:19px;color:var(--ink-2);max-width:34em}
.hero .cta{margin-top:34px;display:flex;flex-wrap:wrap;gap:12px}
.hero .meta{margin-top:18px;font-size:14px;color:var(--ink-2);display:flex;gap:18px;flex-wrap:wrap}
.hero .meta span{display:inline-flex;align-items:center;gap:6px}

/* 信封 */
.envelope{position:relative;background:var(--stamp);border:1px solid var(--line);border-radius:6px;padding:18px;box-shadow:0 24px 48px -28px rgba(19,35,47,.35);transform:rotate(-1.2deg)}
.envelope::before{content:"";position:absolute;inset:0;border-radius:6px;padding:7px;background:repeating-linear-gradient(135deg,var(--post-red) 0 16px,transparent 16px 32px,var(--accent) 32px 48px,transparent 48px 64px);-webkit-mask:linear-gradient(#000 0 0) content-box,linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude;pointer-events:none}
.env-head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;padding:10px 8px 0}
.env-to{font-family:var(--display);font-weight:600;font-size:15px;color:var(--ink-2);line-height:1.6}
.env-to b{display:block;font-size:20px;color:var(--ink);font-weight:900}
.stamp{position:relative;width:74px;height:90px;background:var(--stamp);border:1px solid var(--line);padding:6px;flex:none;
  background-image:radial-gradient(circle at 0 0,var(--paper) 3px,transparent 3.5px);background-size:12px 12px}
.stamp img{width:100%;height:100%;object-fit:cover;border-radius:4px;background:var(--sky)}
.stamp i{position:absolute;left:0;right:0;bottom:-4px;text-align:center;font-style:normal;font-size:9px;letter-spacing:.08em;color:var(--ink-2);background:var(--stamp);padding:0 4px;width:max-content;margin:0 auto}
.postmark{position:absolute;right:62px;top:14px;width:84px;height:84px;border:2px solid var(--post-red);border-radius:50%;opacity:.75;transform:rotate(-14deg);display:grid;place-items:center;color:var(--post-red);font-size:10px;letter-spacing:.14em;text-align:center;line-height:1.3;font-weight:700;font-family:var(--body)}
.postmark::before{content:"";position:absolute;inset:6px;border:1px solid var(--post-red);border-radius:50%}
.postmark span{position:relative;display:block;font-size:13px;letter-spacing:.02em}
.words{margin:20px 6px 8px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;counter-reset:w}
.words li{list-style:none;counter-increment:w;display:flex;align-items:baseline;gap:7px;background:var(--paper);border:1px solid var(--line);border-radius:6px;padding:7px 10px;font-size:15px;font-weight:500;font-variant-numeric:tabular-nums;min-width:0}
.words li::before{content:counter(w,decimal-leading-zero);font-size:11px;color:var(--ink-2);font-weight:400}
.words li span{overflow-wrap:anywhere}
.env-foot{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:6px 8px 4px;font-size:13px;color:var(--ink-2)}
.env-foot button{font:inherit;color:var(--accent-ink);background:none;border:0;padding:4px 0;cursor:pointer;text-decoration:underline;text-underline-offset:3px}

/* 通用版块 */
.section{padding-block:88px}
.section-head{max-width:40em}
.section h2{font-size:clamp(28px,3.4vw,40px)}
.section .sub{margin-top:14px;color:var(--ink-2);font-size:18px}
.band{background:var(--paper-2)}

/* 12 个词 */
.facts{margin-top:48px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:40px}
.fact h3{font-size:22px;font-weight:600}
.fact p{margin-top:10px;color:var(--ink-2);font-size:16px}
.fact .mark{width:40px;height:40px;margin-bottom:16px;color:var(--accent)}
.note{margin-top:44px;display:flex;gap:14px;align-items:flex-start;padding:18px 20px;border-left:3px solid var(--post-red);background:var(--stamp);border-radius:0 8px 8px 0;font-size:15px;color:var(--ink)}
.note svg{flex:none;color:var(--post-red);margin-top:3px}

/* 功能 */
.features{margin-top:52px;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:44px 40px}
.feature{display:grid;grid-template-columns:36px minmax(0,1fr);gap:16px;align-items:start}
.feature svg{width:36px;height:36px;color:var(--accent)}
.feature h3{font-size:20px;font-weight:600;font-family:var(--body)}
.feature p{margin-top:6px;color:var(--ink-2);font-size:15.5px}

/* 两个重点 */
.spots{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:28px;margin-top:52px}
.spot{background:var(--stamp);border:1px solid var(--line);border-radius:14px;padding:34px 32px;min-width:0}
.spot h3{font-size:26px}
.spot p{margin-top:12px;color:var(--ink-2)}
.spot ul{margin:20px 0 0;padding:0;list-style:none;display:grid;gap:10px}
.spot li{display:flex;gap:10px;align-items:flex-start;font-size:15.5px}
.spot li::before{content:"";flex:none;width:8px;height:8px;border-radius:50%;background:var(--accent);margin-top:10px}

/* 下载 */
.download .wrap{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:48px;align-items:center}
.dl-actions{margin-top:28px;display:grid;gap:12px;max-width:360px}
.dl-actions .btn{justify-content:flex-start;height:56px;font-size:17px;padding:0 22px}
.dl-actions .btn svg{width:22px;height:22px}
.dl-tip{margin-top:16px;font-size:14px;color:var(--ink-2)}
.qr{background:var(--stamp);border:1px solid var(--line);border-radius:14px;padding:18px;text-align:center;width:232px}
.qr #qr{width:196px;height:196px;margin:0 auto;display:grid;place-items:center}
.qr #qr img,.qr #qr canvas{width:196px!important;height:196px!important}
.qr p{margin-top:10px;font-size:13px;color:var(--ink-2)}

/* 常见问题 */
.faq{margin-top:40px;max-width:46em;border-top:1px solid var(--line)}
.faq details{border-bottom:1px solid var(--line)}
.faq summary{cursor:pointer;list-style:none;padding:20px 0;font-size:18px;font-weight:500;display:flex;justify-content:space-between;gap:16px;align-items:center}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:24px;color:var(--ink-2);font-weight:300;flex:none;transition:transform .2s}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{padding-bottom:22px;color:var(--ink-2);max-width:40em}

/* 页脚 */
footer{border-top:1px solid var(--line);padding-block:40px 48px;font-size:14px;color:var(--ink-2)}
footer .wrap{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:24px;align-items:start}
.contact{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:10px}
.contact code{font-family:var(--body);color:var(--ink);background:var(--paper-2);padding:2px 8px;border-radius:4px;user-select:all}
.contact button{font:inherit;font-size:13px;color:var(--accent-ink);background:none;border:1px solid var(--line);border-radius:999px;padding:2px 10px;cursor:pointer}
.foot-links{display:flex;gap:18px;flex-wrap:wrap}
.foot-links a{color:var(--ink-2);text-decoration:none}
.foot-links a:hover{color:var(--ink)}
.legal{margin-top:18px}

@media (max-width:900px){
  .hero .wrap{grid-template-columns:1fr;gap:40px}
  .facts,.features{grid-template-columns:repeat(2,minmax(0,1fr))}
  .spots{grid-template-columns:1fr}
  .download .wrap{grid-template-columns:1fr}
  .qr{width:100%;max-width:232px}
}
@media (max-width:640px){
  body{font-size:16px}
  .nav .wrap{height:58px;gap:12px}
  .brand small{display:none}
  .nav .btn-sm{padding:0 14px}
  .nav-links{display:none}
  .hero{padding-block:44px 48px}
  .hero .lede{font-size:17px}
  .hero .cta .btn{width:100%}
  .envelope{transform:none;padding:14px}
  .words{grid-template-columns:repeat(2,minmax(0,1fr));margin:16px 2px 6px}
  .postmark{right:52px;top:6px;width:70px;height:70px;font-size:9px}
  .section{padding-block:60px}
  .facts,.features{grid-template-columns:1fr;gap:32px}
  .spot{padding:26px 20px}
  footer .wrap{grid-template-columns:1fr}
}
/* SWAP 兑换页（/swap/） */
.nav-swap{display:inline-flex;align-items:center;gap:6px;height:40px;padding:0 14px;border-radius:999px;border:1.5px solid var(--line);color:var(--ink);text-decoration:none;font-size:14px;font-weight:700;letter-spacing:.04em;margin-left:auto}
.nav-swap svg{width:16px;height:16px;color:var(--accent)}
.nav-swap:hover,.nav-swap[aria-current="page"]{border-color:var(--accent);color:var(--accent-ink)}
.nav-links+.nav-swap{margin-left:0}
.swap-page{padding-block:48px 96px;min-height:70vh;background:linear-gradient(180deg,var(--sky) 0%,var(--paper) 38%)}
.swap-page .wrap{display:grid;grid-template-columns:minmax(0,1fr) 440px minmax(0,1fr);gap:24px;align-items:start}
.swap-side{padding-top:12px;font-size:15px;color:var(--ink-2)}
.swap-side h1{font-size:30px;color:var(--ink)}
.swap-side p{margin-top:12px;max-width:22em}
.swap-side .pairs{margin-top:22px;display:grid;gap:8px;list-style:none;padding:0}
.swap-side .pairs li{display:flex;justify-content:space-between;gap:12px;font-variant-numeric:tabular-nums;border-top:1px solid var(--line);padding-top:8px}
.swap-side .pairs b{font-weight:500;color:var(--ink)}
.swap-card{background:var(--stamp);border:1px solid var(--line);border-radius:20px;padding:14px;box-shadow:0 24px 48px -32px rgba(19,35,47,.4);min-width:0}
.swap-top{display:flex;align-items:center;gap:4px;padding:4px 6px 10px}
.swap-top .tab{font:inherit;font-weight:500;font-size:15px;color:var(--ink-2);background:none;border:0;padding:6px 10px;border-radius:999px;cursor:pointer}
.swap-top .tab[aria-selected="true"]{color:var(--ink);background:var(--paper-2)}
.swap-top .gear{margin-left:auto;font:inherit;font-size:13px;color:var(--ink-2);background:none;border:1px solid var(--line);border-radius:999px;padding:4px 12px;cursor:pointer;display:inline-flex;align-items:center;gap:6px}
.swap-top .gear svg{width:14px;height:14px}
.box{background:var(--paper);border:1px solid transparent;border-radius:14px;padding:14px 16px 12px;min-width:0}
.box:focus-within{border-color:var(--accent)}
.box .lab{font-size:13px;color:var(--ink-2)}
.box .row{display:flex;align-items:center;gap:12px;margin-top:4px}
.box input{flex:1;min-width:0;width:100%;font:inherit;font-size:32px;font-weight:500;color:var(--ink);background:none;border:0;padding:0;outline:0;font-variant-numeric:tabular-nums}
.box input::placeholder{color:var(--ink-2);opacity:.6}
.box .foot{display:flex;justify-content:space-between;gap:12px;margin-top:6px;font-size:13px;color:var(--ink-2);font-variant-numeric:tabular-nums}
.box .foot button{font:inherit;font-size:12px;color:var(--accent-ink);background:var(--accent-soft);border:0;border-radius:999px;padding:1px 8px;cursor:pointer}
.tok{flex:none;display:inline-flex;align-items:center;gap:8px;height:40px;padding:0 10px 0 6px;border-radius:999px;background:var(--stamp);border:1px solid var(--line);font:inherit;font-weight:700;font-size:16px;color:var(--ink);cursor:pointer}
.tok:hover{border-color:var(--ink)}
.tok .coin{width:26px;height:26px;border-radius:50%;display:grid;place-items:center;font-size:11px;font-weight:700;color:#fff;letter-spacing:0}
.tok svg{width:14px;height:14px;color:var(--ink-2)}
.coin[data-c="ZERO"]{background:#0C8A6B}.coin[data-c="USDT"]{background:#26A17B}.coin[data-c="BNB"]{background:#C99A1E}.coin[data-c="USDC"]{background:#2775CA}
.flip{display:grid;place-items:center;height:12px;position:relative;z-index:1}
.flip button{width:40px;height:40px;border-radius:12px;border:4px solid var(--stamp);background:var(--paper-2);color:var(--ink);cursor:pointer;display:grid;place-items:center;transition:transform .25s}
.flip button:hover{transform:rotate(180deg)}
.flip svg{width:18px;height:18px}
.rate{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:12px 8px 4px;font-size:14px;color:var(--ink-2);font-variant-numeric:tabular-nums}
.rate button{font:inherit;color:var(--ink);background:none;border:0;padding:0;cursor:pointer;text-align:left}
.details{margin:6px 2px 0;border:1px solid var(--line);border-radius:12px;font-size:14px}
.details summary{list-style:none;cursor:pointer;padding:10px 14px;display:flex;justify-content:space-between;color:var(--ink-2)}
.details summary::-webkit-details-marker{display:none}
.details summary::after{content:"+";font-size:18px;line-height:1}
.details[open] summary::after{content:"−"}
.details dl{margin:0;padding:4px 14px 12px;display:grid;grid-template-columns:1fr auto;gap:8px 16px;font-variant-numeric:tabular-nums}
.details dt{color:var(--ink-2)}.details dd{margin:0;text-align:right;color:var(--ink)}
.swap-cta{margin-top:12px;width:100%;height:56px;font-size:18px;border-radius:14px}
.swap-cta[disabled]{opacity:.5;cursor:not-allowed}
.swap-msg{margin-top:12px;font-size:13px;color:var(--ink-2);text-align:center;min-height:1.5em}
.slip{display:none;margin:0 2px 10px;padding:12px 14px;border:1px solid var(--line);border-radius:12px;font-size:14px}
.slip[data-open="true"]{display:block}
.slip .opts{display:flex;gap:8px;margin-top:8px;flex-wrap:wrap}
.slip .opts button{font:inherit;font-size:14px;padding:4px 12px;border-radius:999px;border:1px solid var(--line);background:none;color:var(--ink);cursor:pointer}
.slip .opts button[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:#fff}
.picker{position:fixed;inset:0;z-index:20;display:none;align-items:center;justify-content:center;padding:max(16px,env(safe-area-inset-left,0px));background:rgba(10,20,28,.45)}
.picker[data-open="true"]{display:flex}
.picker .sheet{width:100%;max-width:400px;background:var(--stamp);border-radius:18px;padding:18px;max-height:80vh;overflow:auto}
.picker h3{font-family:var(--body);font-size:18px;font-weight:600;display:flex;justify-content:space-between;align-items:center}
.picker h3 button{font:inherit;font-size:22px;background:none;border:0;color:var(--ink-2);cursor:pointer;line-height:1}
.picker input{width:100%;margin-top:12px;font:inherit;font-size:15px;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:var(--paper);color:var(--ink)}
.picker ul{list-style:none;margin:12px 0 0;padding:0}
.picker li button{width:100%;display:flex;align-items:center;gap:12px;font:inherit;background:none;border:0;padding:10px 6px;border-radius:10px;cursor:pointer;color:var(--ink);text-align:left}
.picker li button:hover{background:var(--paper-2)}
.picker li .coin{width:32px;height:32px;border-radius:50%;display:grid;place-items:center;font-size:12px;font-weight:700;color:#fff}
.picker li b{display:block;font-weight:600}.picker li small{color:var(--ink-2);font-size:13px}
.picker li .bal{margin-left:auto;font-variant-numeric:tabular-nums;color:var(--ink-2);font-size:14px}
@media (max-width:900px){
  .swap-page .wrap{grid-template-columns:1fr}
  .swap-side:last-child{display:none}
}
@media (max-width:640px){
  .nav-swap{height:36px;padding:0 12px;font-size:13px}
  .swap-page{padding-block:24px 64px}
  .swap-side h1{font-size:26px}
  .box input{font-size:28px}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}.faq summary::after,.flip button{transition:none}}