:root {
  --bg: #08101f;
  --surface: rgba(10, 18, 33, 0.94);
  --surface-soft: rgba(11, 20, 39, 0.85);
  --surface-alt: rgba(255,255,255,0.05);
  --text: #e9f3ff;
  --heading: #ffffff;
  --muted: #a9bed6;
  --accent: #6ed7ff;
  --accent-dark: #38b4f0;
  --accent-alt: #f8d16a;
  --border: rgba(110, 215, 255, 0.16);
  --radius: 28px;
  --shadow: 0 34px 120px rgba(0, 0, 0, 0.28);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: radial-gradient(circle at top left, rgba(110, 215, 255, 0.18), transparent 26rem),
    radial-gradient(circle at bottom right, rgba(110, 215, 255, 0.10), transparent 18rem),
    #051127;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}

a:hover,
a:focus {
  color: var(--accent-dark);
  transform: translateY(-1px);
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 48px 24px 72px;
}

.hero {
  padding: 42px 36px;
  border-radius: var(--radius);
  background: rgba(10, 18, 34, 0.90);
  border: 1px solid rgba(110, 215, 255, 0.12);
  box-shadow: var(--shadow);
  margin-bottom: 32px;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--heading);
  margin: 0;
}

h1 {
  font-size: clamp(2.4rem, 4vw, 4.4rem);
  line-height: 1.05;
}

h2 {
  font-size: clamp(1.8rem, 2.5vw, 2.6rem);
  line-height: 1.12;
}

h3 {
  font-size: 1.25rem;
  line-height: 1.5;
}

p,
li {
  color: var(--muted);
}

p {
  margin: 0 0 1.25rem;
}

ul,
ol {
  margin: 0 0 1.25rem;
  padding-left: 1.5rem;
}

li {
  margin-bottom: 0.9rem;
}

.subtitle {
  color: var(--muted);
  margin-top: 18px;
  margin-bottom: 0;
  max-width: 760px;
  line-height: 1.75;
}

.app,
.card,
.section-card,
.box,
.content,
footer {
  border-radius: 20px;
}

.app,
.card,
.section-card,
.box,
.content {
  background: rgba(10, 18, 34, 0.92);
  border: 1px solid rgba(110, 215, 255, 0.12);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.20);
}

.app,
.card,
.section-card {
  margin-bottom: 28px;
  padding: 26px;
}

.box {
  padding: 26px;
}

.links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.links a,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.links a.primary,
.button {
  background: var(--accent);
  color: #051127;
}

.links a.secondary,
.button.secondary {
  background: rgba(110, 215, 255, 0.10);
  color: var(--text);
  border-color: rgba(110, 215, 255, 0.14);
}

.links a:hover,
.button:hover,
.links a:focus {
  transform: translateY(-1px);
}

footer {
  margin-top: 50px;
  padding-top: 32px;
  color: var(--muted);
  text-align: center;
  font-size: 0.95rem;
}

footer a {
  color: var(--accent);
}

.top-nav,
.page-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 30px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(110, 215, 255, 0.12);
  color: var(--muted);
}

.top-nav a,
.page-nav a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 700;
}

.page-header {
  padding: 22px 0 18px;
}

.meta,
.notice,
.toc,
.grid,
.callout {
  margin-bottom: 24px;
}

.meta {
  padding: 22px 24px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(110, 215, 255, 0.14);
  color: var(--muted);
}

.notice {
  padding: 22px 24px;
  border-radius: 20px;
  background: rgba(110, 215, 255, 0.12);
  border: 1px solid rgba(110, 215, 255, 0.18);
  color: var(--heading);
}

.toc {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.toc a {
  display: block;
  padding: 16px 18px;
  border-radius: 18px;
  border: 1px solid rgba(110, 215, 255, 0.14);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  font-weight: 700;
}

.grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.callout {
  padding: 22px 24px;
  border-radius: 20px;
  border: 1px solid rgba(110, 215, 255, 0.18);
  background: rgba(110, 215, 255, 0.08);
  color: var(--heading);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 18px;
}

th,
td {
  padding: 14px 16px;
  border: 1px solid rgba(110, 215, 255, 0.14);
  text-align: left;
  vertical-align: top;
}

th {
  background: rgba(110, 215, 255, 0.08);
  color: var(--heading);
}

select,
input,
textarea {
  width: 100%;
  max-width: 100%;
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  font: inherit;
  margin-top: 10px;
}

select:focus,
input:focus,
textarea:focus,
a:focus {
  outline: 3px solid rgba(110, 215, 255, 0.35);
  outline-offset: 2px;
}

@media (max-width: 760px) {
  .hero,
  .content,
  .meta,
  .notice,
  .card,
  .box {
    padding: 24px;
  }

  .links,
  .page-nav,
  .top-nav,
  .toc {
    gap: 12px;
  }
}