:root {
  /* Dark theme */
  --bg: #141922;
  --bg-alt: #1a2029;
  --text: #e1e5ee;
  --text-muted: #a5afbd;

  /* Light sections */
  --bg-light: #f3f4f6;

  /* Accent & semantic colors */
  --accent: #ffc27f;
  --accent-strong: #ff9b2f;
  --accent-light: #d97706;
  --accent-strong-light: #b45309;
  --danger: #ff6b6b;

  --border: #2f3742;
  --shadow-soft: 0 10px 25px rgba(0, 0, 0, 0.28);

  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: radial-gradient(circle at top left, #1c2532 0, #090c12 55%);
  color: var(--text);
  line-height: 1.6;
}

/* Layout helpers */

.container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 3rem 0;
}

.section.light {
  background: var(--bg-light);
  color: #111827;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(5, 8, 12, 0.95);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(10px);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 64px;
}

.branding {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-circle {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 20%, #ffe5c0, #c27d42);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
}

.site-title {
  margin: 0;
  font-size: 1.1rem;
  letter-spacing: 0.03em;
}

.site-subtitle {
  margin: 0;
  margin-top: 0.1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.main-nav a {
  margin-left: 1rem;
  font-size: 0.9rem;
  text-decoration: none;
  color: var(--text-muted);
  padding: 0.3rem 0;
  position: relative;
}

.main-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -0.2rem;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.2s ease;
}

.main-nav a:hover {
  color: var(--text);
}

.main-nav a:hover::after {
  width: 100%;
}

/* Hero */

.hero {
  padding: 3.5rem 0 3rem;
}

.hero-inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.hero-text h2 {
  font-size: 2rem;
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.hero-text p {
  max-width: 36rem;
  color: var(--text-muted);
  font-size: 1rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 0.6rem 1.4rem;
  border: 1px solid transparent;
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.08s ease, box-shadow 0.08s ease;
  background: 0.15s ease, border-color 0.15s ease;
}

.button.primary {
  background: linear-gradient(135deg, var(--accent-strong), var(--accent));
  color: #1f1307;
  font-weight: 600;
  box-shadow: var(--shadow-soft);
}

.button.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.4);
}

/* Sections */

.section h2 {
  margin-top: 0;
  margin-bottom: 0.75rem;
  font-size: 1.5rem;
}

.section h3 {
  margin-top: 1.5rem;
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.section p {
  margin-top: 0.2rem;
  margin-bottom: 0.75rem;
}

.section.light h2,
.section.light h3 {
  color: #111827;
}

.section.light p,
.section.light li {
  color: #374151;
}

/* Lists */

ul {
  margin: 0.3rem 0 0.8rem;
  padding-left: 1.3rem;
}

li {
  margin-bottom: 0.3rem;
}

/* Grid */

.grid.two {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

/* Hints / notes */

.hint {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.section.light .hint {
  color: #6b7280;
}

/* Footer */

.site-footer {
  border-top: 1px solid var(--border);
  background: rgba(5, 8, 12, 0.95);
  padding: 1.5rem 0 2rem;
}

.footer-inner {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-inner .small {
  margin-top: 0.4rem;
}

/* Links */

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

a:hover {
  color: var(--accent-strong);
}

.section.light a {
  color: var(--accent-light)
}

.section.light a:hover {
  color: var(--accent-strong-light);
}

/* Responsive */

@media (max-width: 720px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .main-nav {
    margin-top: 0.3rem;
    display: flex;
    flex-wrap: wrap;
  }

  .main-nav a {
    margin: 0.2rem 0.8rem 0.2rem 0;
  }

  .hero {
    padding-top: 2.4rem;
  }

  .grid.two {
    grid-template-columns: 1fr;
  }
}

/* Accessibility */

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: #000;
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
}

.skip-link:focus {
  left: 0.75rem;
  top: 0.75rem;
}

[id] {
  scroll-margin-top: 80px;
}

a:focus-visible,
.button:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}