:root {
  --bg: #f6f7fb;
  --fg: #1f2733;
  --muted: #5b6472;
  --accent: #2b3a52;
  --accent-light: #63aae0;
  --card-bg: #ffffff;
  --border: #e3e6ec;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
}

a {
  color: var(--accent-light);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

header.site {
  background: var(--accent);
  color: #fff;
}

header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 1.15rem;
  color: #fff;
}

.logo .mark {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  background: var(--accent-light);
  display: inline-block;
}

nav.main a {
  color: #dfe6f0;
  margin-left: 26px;
  font-size: 0.95rem;
}

nav.main a:hover {
  color: #fff;
}

.hero {
  background: linear-gradient(180deg, var(--accent) 0%, #34455f 100%);
  color: #fff;
  padding: 72px 0 84px;
}

.hero h1 {
  font-size: 2.3rem;
  margin: 0 0 14px;
  max-width: 640px;
}

.hero p {
  color: #cfd8e6;
  max-width: 560px;
  margin: 0 0 28px;
  font-size: 1.05rem;
}

.btn {
  display: inline-block;
  background: var(--accent-light);
  color: #10202f;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: 6px;
}

.btn:hover {
  background: #7fbcea;
  text-decoration: none;
}

section {
  padding: 64px 0;
}

section h2 {
  font-size: 1.6rem;
  margin: 0 0 8px;
}

section .lead {
  color: var(--muted);
  margin: 0 0 36px;
  max-width: 620px;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 26px;
}

.card h3 {
  margin: 0 0 10px;
  font-size: 1.1rem;
}

.card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.split {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: start;
}

.panel {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px;
}

.panel dl {
  margin: 0;
}

.panel dt {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 14px;
}

.panel dt:first-child {
  margin-top: 0;
}

.panel dd {
  margin: 2px 0 0;
  font-size: 1rem;
}

footer.site {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
  padding: 26px 0;
}

footer.site .wrap {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

.notfound {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 80px 24px;
}

.notfound .code {
  font-size: 4.5rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0;
}

.notfound p {
  color: var(--muted);
  margin: 10px 0 26px;
}

@media (max-width: 720px) {
  .cards {
    grid-template-columns: 1fr;
  }
  .split {
    grid-template-columns: 1fr;
  }
  nav.main {
    display: none;
  }
}