:root {
  --color-primary: #3E6AE1;
  --color-electric-blue: #3E6AE1;
  --color-white: #FFFFFF;
  --color-light-ash: #F4F4F4;
  --color-carbon: #171A20;
  --color-graphite: #393C41;
  --color-pewter: #5C5E62;
  --color-silver-fog: #8E8E8E;
  --color-cloud: #EEEEEE;
  --color-pale-silver: #D0D1D2;
  --color-frost: rgba(255, 255, 255, 0.75);
  --rounded-btn: 4px;
  --rounded-card: 12px;
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 21.44px;
  --font-display: "Universal Sans Display", system-ui, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  --font-text: "Universal Sans Text", system-ui, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  --ease: 0.33s cubic-bezier(0.5, 0, 0, 0.75);
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: var(--font-text);
  color: var(--color-graphite);
  background: var(--color-white);
  font-size: 14px;
  font-weight: 400;
  line-height: 20px;
  padding-bottom: 56px;
}
a { color: var(--color-pewter); text-decoration: none; transition: color var(--ease); }
a:hover { color: var(--color-carbon); }
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--color-frost);
  backdrop-filter: blur(16px);
}
.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  min-height: 56px;
  flex-wrap: wrap;
}
.logo {
  font-family: var(--font-display);
  font-weight: 500;
  color: var(--color-carbon);
  font-size: 17px;
  letter-spacing: 0.42em;
  text-transform: uppercase;
  text-decoration: none;
}
.nav { display: flex; flex-wrap: wrap; gap: 4px; flex: 1; justify-content: center; }
.nav a {
  color: var(--color-carbon);
  font-size: 14px;
  font-weight: 500;
  line-height: 16.8px;
  padding: 4px 16px;
  min-height: 32px;
  display: inline-flex;
  align-items: center;
  border-radius: var(--rounded-btn);
  transition: background-color var(--ease), color var(--ease);
}
.nav a:hover, .nav a.on { background: var(--color-light-ash); }
.back { margin-left: auto; font-size: 14px; color: var(--color-pewter); }

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: #c8ccd0;
  color: var(--color-white);
  position: relative;
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(23, 26, 32, 0.28);
}
.hero .wrap { position: relative; z-index: 1; }
.hero h1 {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 500;
  line-height: 48px;
  letter-spacing: normal;
  margin: 0 0 8px;
  color: var(--color-white);
}
.hero p {
  margin: 0 0 24px;
  color: var(--color-white);
  font-size: 22px;
  font-weight: 400;
  line-height: 20px;
}
.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  width: 200px;
  padding: 4px 16px;
  border: 3px solid transparent;
  border-radius: var(--rounded-btn);
  background: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-text);
  font-size: 14px;
  font-weight: 500;
  line-height: 16.8px;
  cursor: pointer;
  text-decoration: none;
  transition: border-color 0.33s, background-color 0.33s, color 0.33s, box-shadow 0.25s;
}
.btn:hover { background: #3459c4; color: var(--color-white); text-decoration: none; }
.btn-secondary {
  background: var(--color-white);
  color: var(--color-graphite);
  width: 160px;
}
.btn-secondary:hover { background: var(--color-light-ash); color: var(--color-graphite); }

.section { padding: 80px 0; background: var(--color-white); }
.section.ash { background: var(--color-light-ash); }
.section h2 {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 500;
  line-height: 48px;
  color: var(--color-carbon);
  margin: 0 0 32px;
  text-align: center;
}
.muted { color: var(--color-pewter); text-align: center; max-width: 40em; margin: 0 auto 32px; }

.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.grid-2 { display: grid; grid-template-columns: 1.4fr 1fr; gap: 16px; }
.card {
  background: transparent;
  border: 0;
  padding: 0;
  text-align: center;
}
.card h3 {
  margin: 12px 0 4px;
  font-size: 17px;
  font-weight: 500;
  line-height: 20px;
  color: var(--color-carbon);
}
.card p { margin: 0; color: var(--color-pewter); font-size: 14px; }
.card .links { margin-top: 8px; display: flex; justify-content: center; gap: 16px; }

.cat {
  position: relative;
  height: 280px;
  border-radius: var(--rounded-card);
  overflow: hidden;
  background: #c8ccd0;
  color: var(--color-white);
}
.cat span {
  position: absolute;
  top: 16px;
  left: 16px;
  font-size: 16px;
  font-weight: 500;
  color: var(--color-white);
}

.list { list-style: none; margin: 0 auto; padding: 0; max-width: 720px; }
.list li { padding: 16px 0; border-bottom: 1px solid var(--color-cloud); display: flex; gap: 16px; }
.list li:last-child { border-bottom: 0; }
.list .date { color: var(--color-silver-fog); min-width: 96px; }

.ph {
  background: var(--color-light-ash);
  color: var(--color-silver-fog);
  height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
}

form label { display: block; margin: 0 0 4px; font-size: 14px; color: var(--color-carbon); }
form input, form textarea {
  width: 100%;
  max-width: 480px;
  padding: 8px 0;
  border: 0;
  border-bottom: 1px solid var(--color-pale-silver);
  font: inherit;
  color: var(--color-carbon);
  background: transparent;
  margin-bottom: 16px;
}
form input::placeholder { color: var(--color-silver-fog); }

.footer {
  padding: 48px 0 80px;
  color: var(--color-pewter);
  font-size: 14px;
  text-align: center;
}
.footer p { margin: 0 0 4px; }

.chatbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-white);
  border-top: 1px solid var(--color-cloud);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 24px;
  z-index: 30;
}
.chatbar input {
  flex: 1;
  border: 0;
  font: inherit;
  padding: 8px;
  color: var(--color-carbon);
}
.chatbar input::placeholder { color: var(--color-silver-fog); }
.chatbar .ask { font-weight: 500; color: var(--color-carbon); white-space: nowrap; }

@media (max-width: 768px) {
  .grid, .grid-2 { grid-template-columns: 1fr; }
  .hero { min-height: 80vh; }
  .hero h1, .section h2 { font-size: 28px; line-height: 34px; }
  .hero-actions { flex-direction: column; align-items: center; }
  .btn, .btn-secondary { width: 200px; }
}

.ph { overflow: hidden; }
.ph img { width: 100%; height: 100%; object-fit: cover; display: block; }