*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #0b0d10;
  --bg-elevated: #111418;
  --surface: #161a20;
  --border: #2a3139;
  --border-bright: #3d4652;
  --text: #d4d8de;
  --text-muted: #7a8490;
  --accent: #c9a227;
  --accent-dim: #8a7020;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --sans: "IBM Plex Sans", system-ui, sans-serif;
  --max-width: 960px;
  --header-height: 4rem;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.grid-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(42, 49, 57, 0.35) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 49, 57, 0.35) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 20%, transparent 100%);
}

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(11, 13, 16, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text);
}

.logo-img {
  display: block;
  height: 2rem;
  width: auto;
}

.logo-text {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.site-nav ul {
  display: flex;
  gap: 0.25rem;
  list-style: none;
}

.site-nav a {
  display: block;
  padding: 0.5rem 0.875rem;
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--text-muted);
  border: 1px solid transparent;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--accent);
  border-color: var(--border);
  background: var(--surface);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 2.5rem;
  height: 2.5rem;
  padding: 0.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--text);
  transition: transform 0.2s, opacity 0.2s;
}

/* Hero */

.hero {
  padding: 5rem 0 4rem;
  border-bottom: 1px solid var(--border);
}

.hero-label {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.06em;
  margin-bottom: 1rem;
}

.hero-lead {
  max-width: 36rem;
  font-size: 1.0625rem;
  color: var(--text-muted);
}

/* Sections */

.section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border);
}

.section-header {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.section-index {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-dim);
  letter-spacing: 0.1em;
}

.section-header h2 {
  font-family: var(--mono);
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.panel {
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-dim);
  color: var(--text-muted);
}

.panel p {
  max-width: 40rem;
}

.panel a {
  font-family: var(--mono);
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-dim);
  transition: color 0.2s, border-color 0.2s;
}

.panel a:hover,
.panel a:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
}

/* Footer */

.site-footer {
  padding: 2rem 0;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.footer-meta {
  color: var(--accent-dim);
}

/* Mobile nav */

@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    padding: 1rem;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.25s, opacity 0.25s, visibility 0.25s;
  }

  .site-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .site-nav ul {
    flex-direction: column;
  }

  .site-nav a {
    padding: 0.75rem 1rem;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }
}