* { margin: 0; padding: 0; box-sizing: border-box; }
  html, body { height: 100%; overflow: hidden; }
  body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: #060d1a;
    color: #e6eef8;
    position: relative;
  }

  /* ============ 背景层 ============ */
  .bg {
    position: fixed; inset: 0; z-index: 0;
    background:
      radial-gradient(ellipse 80% 60% at 75% 40%, rgba(0, 120, 180, 0.25) 0%, transparent 60%),
      radial-gradient(ellipse 60% 50% at 20% 80%, rgba(0, 80, 140, 0.2) 0%, transparent 60%),
      linear-gradient(135deg, #060d1a 0%, #0a1a30 50%, #0d2240 100%);
  }
  /* 网格 */
  .bg::before {
    content: ''; position: absolute; inset: 0;
    background-image:
      linear-gradient(rgba(0, 212, 255, 0.04) 1px, transparent 1px),
      linear-gradient(90deg, rgba(0, 212, 255, 0.04) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: radial-gradient(ellipse 90% 80% at 50% 50%, black 40%, transparent 100%);
  }
  /* 扫描线 */
  .scanline {
    position: absolute; left: 0; right: 0; height: 120px;
    background: linear-gradient(180deg, transparent 0%, rgba(0, 212, 255, 0.06) 50%, transparent 100%);
    animation: scan 8s linear infinite;
    pointer-events: none;
  }
  @keyframes scan {
    0% { top: -120px; } 100% { top: 100%; }
  }
  /* 噪点 */
  .grain {
    position: absolute; inset: 0; opacity: 0.03; pointer-events: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='200'%3E%3Cfilter id='n'%3E%3CfeTurbulence baseFrequency='0.9'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  }

  /* ============ HUD 装饰 ============ */
  .hud {
    position: fixed; inset: 0; z-index: 1; pointer-events: none;
  }
  .hud svg { width: 100%; height: 100%; }

  /* ============ 顶部导航 ============ */
  .topbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 10;
    display: flex; justify-content: space-between; align-items: center;
    padding: 28px 48px;
  }
  .brand-logo { display: flex; flex-direction: column; gap: 2px; }
  .brand-logo .name {
    font-size: 26px; font-weight: 900; letter-spacing: 1px; color: #fff;
    font-family: 'Times New Roman', Times, serif;
  }
  .brand-logo .name sup { font-size: 12px; color: #fff; }
  .brand-logo .sub {
    font-size: 14px; color: #6b86a8; letter-spacing: 0.5px;
    font-family: 'Times New Roman', Times, serif;
  }
  .brand-logo .support { font-size: 12px; line-height: 1.6; color: #00d4ff; margin-top: 3px; }
  .topbar-right {
    font-family: 'JetBrains Mono', monospace; font-size: 11px; color: #4a6584;
    display: flex; gap: 24px;
  }
  .topbar-right span::before {
    content: ''; display: inline-block; width: 6px; height: 6px; border-radius: 50%;
    background: #00d4ff; margin-right: 8px; vertical-align: middle;
    box-shadow: 0 0 8px #00d4ff;
  }

  /* ============ 主体布局 ============ */
  .main {
    position: relative; z-index: 5;
    height: 100%;
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    align-items: center;
    padding: 0 48px;
    gap: 40px;
  }

  /* 左侧品牌区 */
  .hero { padding-left: 24px; }
  .hero .eyebrow {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px; color: #00d4ff; letter-spacing: 3px;
    margin-bottom: 20px; display: flex; align-items: center; gap: 12px;
  }
  .hero .eyebrow::before {
    content: ''; width: 32px; height: 1px; background: #00d4ff;
  }
  .hero h1 {
    font-size: 88px; font-weight: 900; line-height: 0.95;
    letter-spacing: -2px; color: #fff;
    background: linear-gradient(180deg, #ffffff 0%, #8ec5e8 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
  }
  .hero .en {
    font-family: 'JetBrains Mono', monospace;
    font-size: 15px; color: #6b86a8; font-weight: 400;
    letter-spacing: 0.5px; margin-bottom: 28px;
  }
  .hero .zh {
    font-size: 26px; font-weight: 700; color: #e6eef8; margin-bottom: 16px;
  }
  .hero .desc {
    font-size: 14px; line-height: 1.9; color: #8ba3c7;
    max-width: 460px; font-weight: 300;
  }
  .hero .desc b { color: #c9ddf0; font-weight: 500; }

  /* 数据条 */
  .stats {
    display: flex; gap: 40px; margin-top: 40px;
    padding-top: 28px;
    border-top: 1px solid rgba(0, 212, 255, 0.12);
  }
  .stat .num {
    font-family: 'JetBrains Mono', monospace;
    font-size: 30px; font-weight: 700; color: #00d4ff;
    text-shadow: 0 0 20px rgba(0, 212, 255, 0.4);
  }
  .stat .num em {
    font-style: normal;
    font-size: 20px; font-weight: 500;
    color: #7fd8f5;
    margin-left: 1px;
  }
  .stat .num.stat-3d {
    display: flex; align-items: center; gap: 6px;
    white-space: nowrap;
  }
  .bone-ico {
    width: 20px; height: 20px;
    filter: drop-shadow(0 0 6px rgba(0, 212, 255, 0.8));
  }
  .stats { gap: 32px; }
  .stat .label { white-space: nowrap; }
  .stat .label {
    font-size: 11px; color: #e6eef8; margin-top: 4px; letter-spacing: 1px;
    opacity: 0.85;
  }

  /* ============ 四大功能模块 ============ */
  .features {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 14px 16px;
    margin-top: 26px;
    padding-top: 20px;
    border-top: 1px solid rgba(0, 212, 255, 0.12);
  }
  .feature {
    background: linear-gradient(160deg, rgba(15, 40, 75, 0.35) 0%, rgba(8, 22, 44, 0.4) 100%);
    border: 1px solid rgba(0, 212, 255, 0.14);
    border-radius: 10px;
    padding: 12px 14px 11px;
    transition: border-color 0.2s;
  }
  .feature:hover { border-color: rgba(0, 212, 255, 0.35); }
  .feature .f-head {
    display: flex; align-items: center; gap: 8px;
    font-size: 14px; font-weight: 700; color: #e6eef8;
    margin-bottom: 6px;
  }
  .feature .f-head svg { width: 17px; height: 17px; flex: none; color: #00d4ff;
    filter: drop-shadow(0 0 5px rgba(0, 212, 255, 0.5));
  }
  .feature p {
    font-size: 11.5px; color: #8ba3c7; line-height: 1.7;
    margin-bottom: 9px;
  }
  .feature .tags { display: flex; gap: 6px; flex-wrap: wrap; }
  .feature .tags span {
    font-size: 10px; color: #7fd8f5;
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 3px; padding: 1px 7px;
    background: rgba(0, 212, 255, 0.05);
    letter-spacing: 0.5px;
  }

  /* ============ 登录卡片 ============ */
  .login-wrap {
    display: flex; justify-content: flex-end; align-items: center;
  }
  .login-card {
    width: 420px;
    background: linear-gradient(160deg, rgba(20, 45, 80, 0.55) 0%, rgba(10, 25, 50, 0.65) 100%);
    backdrop-filter: blur(24px) saturate(140%);
    -webkit-backdrop-filter: blur(24px) saturate(140%);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 16px;
    padding: 40px 38px 32px;
    box-shadow:
      0 24px 60px rgba(0, 0, 0, 0.4),
      0 0 0 1px rgba(255, 255, 255, 0.04) inset,
      0 1px 0 rgba(255, 255, 255, 0.08) inset,
      0 0 40px rgba(0, 180, 255, 0.08);
    position: relative;
  }
  /* 卡片顶部高光 */
  .login-card::before {
    content: ''; position: absolute; top: 0; left: 24px; right: 24px; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.6), transparent);
  }

  .login-card h2 {
    font-size: 22px; font-weight: 700; color: #fff; text-align: center;
    margin-bottom: 6px;
  }
  .login-card .sub {
    text-align: center; font-size: 12px; color: #6b86a8; margin-bottom: 32px;
    font-family: 'JetBrains Mono', monospace;
  }

  .field { margin-bottom: 18px; }
  .field label {
    display: block; font-size: 12px; color: #8ba3c7; margin-bottom: 8px;
    letter-spacing: 0.5px;
  }
  .input-row { display: flex; gap: 10px; }
  .input {
    flex: 1;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    padding: 12px 14px;
    color: #fff; font-size: 14px;
    transition: all 0.2s;
    font-family: 'JetBrains Mono', monospace;
  }
  .input::placeholder { color: #4a6584; }
  .input:focus {
    outline: none;
    border-color: #00d4ff;
    background: rgba(0, 212, 255, 0.06);
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.12);
  }
  .btn-code {
    white-space: nowrap;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.3);
    color: #00d4ff;
    padding: 0 16px; border-radius: 8px;
    font-size: 13px; cursor: pointer;
    transition: all 0.2s; font-family: 'Noto Sans SC', sans-serif;
  }
  .btn-code:hover { background: rgba(0, 212, 255, 0.2); }

  .agree {
    display: flex; align-items: flex-start; gap: 8px;
    margin: 18px 0 22px; font-size: 12px; color: #6b86a8;
  }
  .agree input { margin-top: 2px; accent-color: #00d4ff; }
  .agree a { color: #00d4ff; text-decoration: none; }

  .btn-login {
    width: 100%; padding: 13px;
    background: linear-gradient(135deg, #0099cc 0%, #00d4ff 50%, #00e5ff 100%);
    border: none; border-radius: 8px;
    color: #001a26; font-size: 15px; font-weight: 700;
    cursor: pointer; letter-spacing: 2px;
    box-shadow: 0 4px 20px rgba(0, 212, 255, 0.35);
    transition: all 0.25s;
    font-family: 'Noto Sans SC', sans-serif;
  }
  .btn-login:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 28px rgba(0, 212, 255, 0.55);
  }

  .links {
    display: flex; justify-content: space-between;
    margin-top: 18px; font-size: 12px;
  }
  .links a { color: #6b86a8; text-decoration: none; transition: color 0.2s; }
  .links a:hover { color: #00d4ff; }

  .divider {
    height: 1px; background: linear-gradient(90deg, transparent, rgba(255,255,255,0.08), transparent);
    margin: 22px 0 16px;
  }
  .note {
    text-align: center; font-size: 11px; color: #4a6584; line-height: 1.7;
    font-family: 'JetBrains Mono', monospace;
  }

  /* ============ 底部 ============ */
  .footer {
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 10;
    display: flex; justify-content: space-between; align-items: center;
    padding: 18px 48px;
    font-size: 11px; color: #4a6584;
    font-family: 'JetBrains Mono', monospace;
  }
  .footer .right { display: flex; gap: 20px; }
  .footer .copyright { font-size: 12px; text-align: left; line-height: 1.8; overflow-wrap: anywhere; }
  .footer .sao-name { font-family: 'Times New Roman', Times, serif; font-weight: 900; letter-spacing: 1px; }
  .footer .registered-mark { font-family: 'Times New Roman', Times, serif; font-size: 12px; font-weight: 900; line-height: 0; vertical-align: super; }
  @media (max-width: 1024px) { .footer .copyright { text-align: center; } }
  .footer a { color: #4a6584; text-decoration: none; }
  .footer a:hover { color: #8ba3c7; }
  .footer .about-link { padding: 0; border: 0; background: none; color: #4a6584; font: inherit; cursor: pointer; }
  .footer .about-link:hover { color: #8ba3c7; }
  #about-vdip { position: fixed; inset: 0; margin: auto; width: min(460px, calc(100vw - 32px)); max-height: calc(100dvh - 32px); padding: 26px; border: 1px solid #28566d; border-radius: 12px; background: #10253c; color: #e6eef8; }
  #about-vdip::backdrop { background: #020b16b8; }
  #about-vdip h2 { font-size: 20px; margin-bottom: 16px; }
  #about-vdip p { line-height: 1.8; margin-bottom: 12px; }
  #about-vdip button { padding: 10px 20px; margin-top: 8px; }

  /* ============ 响应式 ============ */
  @media (max-width: 1024px) {
    .main { grid-template-columns: 1fr; padding: 80px 24px 60px; overflow-y: auto; }
    .hero { padding-left: 0; text-align: center; }
    .hero h1 { font-size: 56px; }
    .hero .desc { margin: 0 auto; }
    .stats { justify-content: center; }
    .login-wrap { justify-content: center; }
    .login-card { width: 100%; max-width: 420px; }
    .topbar { padding: 20px 24px; }
    .footer { padding: 14px 24px; flex-direction: column; gap: 6px; }
    body { overflow: auto; }
  }

/* Runtime feedback and input binding; v7 brand content remains unchanged. */
#form-status:not(:empty),.field-error:not(:empty){color:#ffc078;font-size:12px;line-height:1.7;margin-top:8px;overflow-wrap:anywhere}
button:disabled{opacity:.55;cursor:not-allowed}
.agree input{flex:0 0 14px;width:14px;height:14px}.agree{line-height:1.7}
dialog#information{position:fixed;inset:0;margin:auto;width:min(460px,calc(100vw - 32px));max-height:calc(100dvh - 32px);padding:26px;border:1px solid #28566d;border-radius:12px;background:#10253c;color:#e6eef8}dialog#information::backdrop{background:#020b16b8}#information h2{font-size:20px;margin-bottom:16px}#information p{line-height:1.8;margin-bottom:20px}#information button{padding:10px 20px} :focus-visible{outline:2px solid #00d4ff;outline-offset:3px}

/* Preserve every v7 element while allowing its single-column breakpoint to fit. */
@media(max-width:1024px){
 html,body{height:auto;min-height:100%;overflow:auto}
 .topbar{position:relative;gap:16px;flex-wrap:wrap}
 .main{height:auto;min-height:0;grid-template-columns:minmax(0,1fr);padding:28px 24px 40px;overflow:visible}
 .hero,.login-wrap,.login-card{min-width:0}
 .stats{flex-wrap:wrap;gap:24px}
 .features{grid-template-columns:repeat(2,minmax(0,1fr))}
 .hero .en{overflow-wrap:anywhere}
 .input{min-width:0;max-width:100%}
 .field>.input{width:100%}
 .footer{position:relative;gap:12px;text-align:center}
 .footer .right{flex-wrap:wrap;justify-content:center;gap:12px}
}
@media(max-width:480px){.login-card{padding:30px 22px}.input-row{gap:8px}.btn-code{padding:0 10px}.features{grid-template-columns:minmax(0,1fr)}.topbar-right{gap:16px}.hero .eyebrow{letter-spacing:1px;font-size:10px}}

/* 164: reserve real layout space for header/footer, including expanded text. */
html { min-height: 100%; height: auto; overflow: auto; }
body { min-height: 100vh; height: auto; overflow: visible; display: flex; flex-direction: column; }
.topbar { position: relative; flex: none; gap: 20px; flex-wrap: wrap; }
.topbar-right { flex-wrap: wrap; }
.main { height: auto; min-height: 0; flex: 1 0 auto; padding-top: 28px; padding-bottom: 40px; grid-template-columns: minmax(0,1.1fr) minmax(0,1fr); }
.hero, .login-wrap, .login-card { min-width: 0; }
.hero .en, .hero .eyebrow { overflow-wrap: anywhere; }
.stats { flex-wrap: wrap; }
.features { grid-template-columns: repeat(2,minmax(0,1fr)); }
.login-card { max-width: 100%; }
.input { min-width: 0; max-width: 100%; }
.field > .input { width: 100%; }
.links { gap: 12px; flex-wrap: wrap; }
.footer { position: relative; flex: none; gap: 16px; flex-wrap: wrap; }
.footer .right { flex-wrap: wrap; gap: 12px 20px; }
@media(max-width:1024px) { .main { grid-template-columns: minmax(0,1fr); } }
@media(max-width:480px) { .features { grid-template-columns: minmax(0,1fr); } }

/* Reserve feedback space before asynchronous authentication starts. */
#form-status{height:auto;min-height:24px;line-height:1.6;overflow-wrap:anywhere;font-size:12px;margin-top:8px;}
.btn-login{transition:box-shadow .25s,transform .25s;}