/* 本地字体：离线打开 HTML 时也能保持一致的排版。 */
@font-face {
  font-family: "DM Sans";
  src: url("./fonts/dm-sans-latin.woff2") format("woff2");
  font-style: normal;
  font-weight: 400 500;
  font-display: swap;
}

/* 浅色主题。修改这些变量即可调整配色。 */
:root {
  --background: #edf2f5;
  --ink: #203749;
  --accent: #55748b;
  --line: rgba(57, 85, 107, 0.2);
  --glow: rgba(159, 186, 205, 0.14);
  --selection: #ccdce7;
}

/* 自动跟随系统主题，没有手动切换开关。 */
@media (prefers-color-scheme: dark) {
  :root {
    --background: #101a23;
    --ink: #e7eef3;
    --accent: #a6c0d3;
    --line: rgba(166, 192, 211, 0.2);
    --glow: rgba(71, 109, 137, 0.12);
    --selection: #355064;
  }
}

* { box-sizing: border-box; }

html { color-scheme: light dark; }

body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: "DM Sans", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--selection); color: var(--ink); }

.page {
  position: relative;
  isolation: isolate;
  display: flex;
  min-height: 100vh;
  min-height: 100svh;
  padding: 64px clamp(32px, 7vw, 128px);
  background:
    radial-gradient(ellipse at 50% 38%, var(--glow), transparent 60%),
    var(--background);
}

/* 细边框与实线角标形成清晰、稳定的页面边界。 */
.page::before {
  content: "";
  position: absolute;
  z-index: -1;
  inset: 24px;
  border: 1px solid var(--line);
  pointer-events: none;
}

.page::after {
  content: "";
  position: absolute;
  z-index: -1;
  top: 24px;
  left: 24px;
  width: 27px;
  height: 27px;
  border-top: 2px solid var(--accent);
  border-left: 2px solid var(--accent);
  pointer-events: none;
}

.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-height: 440px;
  padding: 60px 0;
}

.brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  text-align: center;
}

.shield {
  display: block;
  width: 128px;
  height: auto;
  flex: 0 0 auto;
  margin-bottom: 42px;
}

h1 {
  margin: 0;
  max-width: 100%;
  font-size: clamp(58px, 7.6vw, 118px);
  font-weight: 500;
  line-height: 1.08;
  letter-spacing: -0.055em;
  text-wrap: balance;
  overflow-wrap: break-word;
}

.brand-divider {
  width: 62px;
  height: 2px;
  margin-top: 42px;
  background: var(--accent);
}

@media (min-width: 1600px) {
  .shield { width: 148px; margin-bottom: 48px; }
  .brand-divider { margin-top: 48px; }
}

@media (max-width: 900px) {
  .page { padding: 48px 44px; }
  .shield { width: 118px; margin-bottom: 36px; }
  h1 { font-size: clamp(48px, 7.8vw, 70px); }
}

@media (max-width: 600px) {
  .page { padding: 32px 30px; }
  .page::before { inset: 16px; }
  .page::after { top: 16px; left: 16px; width: 22px; height: 22px; }
  .hero { min-height: 420px; padding: 48px 0; }
  .shield { width: 104px; margin-bottom: 33px; }
  h1 { font-size: clamp(36px, 11.5vw, 62px); line-height: 1.1; letter-spacing: -0.045em; }
  .brand-divider { width: 46px; margin-top: 32px; }
}