:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #14233c;
  --muted: #5f6f88;
  --accent: #0d9488;
  --border: #dde4ef;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", "Noto Sans", sans-serif;
  background: linear-gradient(140deg, #eef3ff 0%, #f8fcff 45%, #f4fffb 100%);
  color: var(--text);
  line-height: 1.65;
}

.container {
  max-width: 860px;
  margin: 40px auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 34px 26px;
  box-shadow: 0 16px 45px rgba(20, 35, 60, 0.08);
}

.hero {
  border-bottom: 1px solid var(--border);
  padding-bottom: 18px;
  margin-bottom: 18px;
}

h1 {
  margin: 0;
  font-size: clamp(1.85rem, 4vw, 2.5rem);
  letter-spacing: 0.01em;
}

.subtitle {
  margin: 8px 0 4px;
  color: var(--accent);
  font-weight: 700;
}

.meta {
  margin: 0;
  color: var(--muted);
}

h2 {
  margin-top: 26px;
  margin-bottom: 8px;
  font-size: 1.2rem;
}

h3 {
  margin: 14px 0 6px;
  font-size: 1rem;
  color: #20406e;
}

p, li {
  font-size: 0.98rem;
}

ul {
  padding-left: 20px;
  margin: 6px 0 10px;
}

@media (max-width: 640px) {
  .container {
    margin: 14px;
    padding: 22px 16px;
    border-radius: 14px;
  }
}