:root {
  --bg: #020617;
  --bg-elevated: #020617;
  --border: #1f2937;
  --primary: #38bdf8;
  --primary-soft: rgba(56, 189, 248, 0.12);
  --text: #e5e7eb;
  --muted: #9ca3af;
  --radius-lg: 18px;
  --radius-md: 12px;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.8);
  --shadow-subtle: 0 10px 25px rgba(15, 23, 42, 0.6);
  --code-bg: #020617;
  --code-border: #1e293b;
  --font-main: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

/* Reset / base */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-main);
  background: radial-gradient(circle at top, #0f172a 0, #020617 45%, #000 100%);
  color: var(--text);
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Hero */
.hero {
  border-bottom: 1px solid var(--border);
  background: radial-gradient(circle at top, #0f172a, #020617 55%, #000 100%);
  padding: 4rem 0 3rem;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -40%;
  background: radial-gradient(circle at 10% 0%, rgba(56, 189, 248, 0.15), transparent 55%);
  opacity: 0.7;
  pointer-events: none;
}

.hero .container {
  position: relative;
  text-align: center;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  background: var(--primary-soft);
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  border: 1px solid rgba(56, 189, 248, 0.4);
}

.badge .icon {
  font-size: 0.95rem;
}

.hero h1 {
  font-size: clamp(2.4rem, 4vw, 3.3rem);
  margin: 0 0 0.75rem;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  margin: 0 auto;
  max-width: 620px;
  color: var(--muted);
  font-size: 1.05rem;
}

.hero-nav {
  margin-top: 2rem;
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.hero-nav a {
  text-decoration: none;
  color: var(--muted);
  font-size: 0.9rem;
  padding: 0.4rem 0.9rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.4);
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(18px);
  transition: all 0.18s ease-out;
}

.hero-nav a:hover {
  color: var(--primary);
  border-color: rgba(56, 189, 248, 0.8);
  background: rgba(15, 23, 42, 0.9);
  transform: translateY(-1px);
}

/* Main */
.main-content {
  padding: 3rem 0 4rem;
}

.section {
  margin-bottom: 2.75rem;
  padding: 1.75rem 1.6rem;
  border-radius: var(--radius-lg);
  background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.06), transparent 55%),
    linear-gradient(to bottom right, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.94));
  border: 1px solid rgba(30, 64, 175, 0.6);
  box-shadow: var(--shadow-subtle);
}

.section h2 {
  margin-top: 0;
  margin-bottom: 0.75rem;
  font-size: 1.4rem;
  letter-spacing: -0.02em;
}

.section p {
  margin: 0.2rem 0 0.9rem;
  color: var(--muted);
}

/* Info boxes */
.info-box {
  border-radius: var(--radius-md);
  padding: 0.9rem 1rem;
  margin: 1.1rem 0 1.2rem;
  font-size: 0.95rem;
  border-width: 1px;
  border-style: solid;
}

.info-box h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.info-box p,
.info-box ul {
  margin: 0;
  color: var(--muted);
}

.info-box ul {
  padding-left: 1.1rem;
}

.info-box--neutral {
  background: rgba(15, 23, 42, 0.75);
  border-color: rgba(148, 163, 184, 0.5);
}

.info-box--blue {
  background: rgba(37, 99, 235, 0.14);
  border-color: rgba(59, 130, 246, 0.8);
}

.info-box--green {
  background: rgba(22, 163, 74, 0.16);
  border-color: rgba(74, 222, 128, 0.8);
}

.info-box--yellow {
  background: rgba(202, 138, 4, 0.16);
  border-color: rgba(250, 204, 21, 0.85);
}

.info-box--red {
  background: rgba(220, 38, 38, 0.14);
  border-color: rgba(248, 113, 113, 0.9);
}

/* Code blocks */
.code-block {
  margin-top: 1.25rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--code-border);
  background: radial-gradient(circle at top, rgba(15, 118, 110, 0.24), transparent 45%),
    var(--code-bg);
  overflow: hidden;
  font-size: 0.9rem;
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.85rem;
  background: linear-gradient(to right, #020617, #0b1120);
  border-bottom: 1px solid var(--code-border);
}

.code-header span {
  font-size: 0.8rem;
  color: var(--muted);
}

.copy-btn {
  font-size: 0.75rem;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.7);
  background: rgba(15, 23, 42, 0.85);
  color: var(--muted);
  cursor: pointer;
  transition: all 0.15s ease-out;
}

.copy-btn:hover {
  border-color: rgba(56, 189, 248, 0.85);
  color: var(--primary);
  transform: translateY(-1px);
}

pre {
  margin: 0;
  padding: 0.9rem 1rem 1rem;
  overflow-x: auto;
  font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;
  font-size: 0.82rem;
  line-height: 1.6;
  color: #e5e7eb;
}

/* Images */
.image-figure {
  margin: 1.6rem 0 0.4rem;
  text-align: left;
}

.result-image {
  width: 100%;
  max-width: 920px;
  display: block;
  border-radius: 14px;
  border: 1px solid rgba(148, 163, 184, 0.45);
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.9);
}

.image-figure figcaption {
  margin-top: 0.5rem;
  font-size: 0.83rem;
  color: var(--muted);
}

.image-grid {
  margin-top: 1.4rem;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 1.3rem 0 1.4rem;
  background: radial-gradient(circle at bottom, #020617, #000 55%);
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

/* Responsive */
@media (max-width: 640px) {
  .section {
    padding: 1.3rem 1.1rem;
  }

  .hero {
    padding: 3rem 0 2.4rem;
  }

  .hero-nav {
    gap: 0.5rem;
  }

  .hero-nav a {
    font-size: 0.8rem;
    padding: 0.3rem 0.7rem;
  }
}