:root {
  --void: #05050A;
  --cyan: #00E5FF;
  --green: #39FF14;
  --text: #E8F0FF;
  --text-mid: #6B7A9A;
  --surface-2: #0C0E1A;
  --border-mid: rgba(0, 229, 255, 0.28);
  --border-soft: rgba(0, 229, 255, 0.14);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  font-weight: 400;
  background-color: var(--void);
  background-image: radial-gradient(circle, rgba(0, 229, 255, 0.12) 1px, transparent 1px);
  background-size: 28px 28px;
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 32px 24px 96px;
}

/* HEADER */
.header {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 24px 0 48px;
  border-bottom: 1px solid var(--border-soft);
  margin-bottom: 48px;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 16px;
  text-decoration: none;
}

.logo-icon {
  height: 56px;
  width: auto;
  mix-blend-mode: screen;
  filter: brightness(3.5);
}

.logo-word {
  height: 32px;
  width: auto;
  mix-blend-mode: screen;
  filter: brightness(3.5);
}

/* NAV */
.nav {
  margin-left: auto;
  display: flex;
  gap: 24px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav a {
  color: var(--text-mid);
  text-decoration: none;
  transition: color 0.2s;
}

.nav a:hover,
.nav a.active {
  color: var(--cyan);
}

/* TYPOGRAPHY */
h1 {
  font-family: "IBM Plex Sans", sans-serif;
  font-weight: 800;
  font-size: clamp(32px, 5vw, 48px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 16px;
}

h2 {
  font-family: "IBM Plex Sans", sans-serif;
  font-weight: 700;
  font-size: 22px;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--cyan);
  margin: 48px 0 16px;
  scroll-margin-top: 32px;
}

h3 {
  font-family: "IBM Plex Sans", sans-serif;
  font-weight: 600;
  font-size: 16px;
  color: var(--text);
  margin: 24px 0 12px;
}

p {
  color: var(--text);
  margin-bottom: 16px;
  font-size: 15.5px;
}

ul, ol {
  margin: 12px 0 20px 24px;
}

li {
  color: var(--text);
  margin-bottom: 8px;
  font-size: 15.5px;
}

strong { font-weight: 600; color: var(--text); }

a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--border-mid);
  transition: border-color 0.2s;
}
a:hover { border-bottom-color: var(--cyan); }

code, .mono {
  font-family: "IBM Plex Mono", monospace;
  font-size: 13.5px;
  color: var(--cyan);
}

/* TAG */
.tag {
  display: inline-block;
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--cyan);
  border: 1px solid var(--border-mid);
  padding: 6px 12px;
  border-radius: 6px;
  margin-bottom: 24px;
}

.subtitle {
  color: var(--text-mid);
  font-size: 16px;
  margin-bottom: 8px;
}

.updated {
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  color: var(--text-mid);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 16px;
  margin-bottom: 32px;
}

/* TABLE OF CONTENTS */
.toc {
  background: var(--surface-2);
  border: 1px solid var(--border-mid);
  border-radius: 8px;
  padding: 24px 28px;
  margin: 32px 0 48px;
  box-shadow: 0 0 24px rgba(0, 229, 255, 0.08);
}

.toc-title {
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--cyan);
  margin-bottom: 14px;
}

.toc ol {
  list-style: none;
  margin: 0;
  counter-reset: toc;
}

.toc li {
  counter-increment: toc;
  font-size: 14px;
  margin-bottom: 6px;
  padding-left: 32px;
  position: relative;
}

.toc li::before {
  content: counter(toc, decimal-leading-zero);
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  color: var(--text-mid);
  position: absolute;
  left: 0;
  top: 2px;
}

.toc a {
  color: var(--text);
  border-bottom: none;
}
.toc a:hover { color: var(--cyan); }

/* CARDS (index) */
.cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 48px;
}

.card {
  background: var(--surface-2);
  border: 1px solid var(--border-mid);
  border-radius: 8px;
  padding: 32px;
  text-decoration: none;
  color: var(--text);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
  box-shadow: 0 0 24px rgba(0, 229, 255, 0.15);
}

.card-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.card-title {
  font-family: "IBM Plex Sans", sans-serif;
  font-weight: 700;
  font-size: 22px;
  line-height: 1.2;
}

.card-desc {
  color: var(--text-mid);
  font-size: 14px;
  margin-top: 4px;
}

.card-arrow {
  margin-top: auto;
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  color: var(--cyan);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* FOOTER */
.footer {
  margin-top: 96px;
  padding-top: 32px;
  border-top: 1px solid var(--border-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  font-family: "IBM Plex Mono", monospace;
  font-size: 12px;
  color: var(--text-mid);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  flex-wrap: wrap;
}

.footer a {
  color: var(--text-mid);
  border-bottom: none;
}
.footer a:hover { color: var(--cyan); }

/* CONTENT BLOCKS */
.intro {
  background: var(--surface-2);
  border-left: 2px solid var(--cyan);
  padding: 20px 24px;
  margin: 32px 0;
  border-radius: 0 6px 6px 0;
  color: var(--text);
  font-size: 15.5px;
}

.contact-box {
  background: var(--surface-2);
  border: 1px solid var(--border-mid);
  border-radius: 8px;
  padding: 24px 28px;
  margin: 32px 0;
  box-shadow: 0 0 24px rgba(0, 229, 255, 0.08);
}

.contact-box .label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--cyan);
  margin-bottom: 8px;
}

/* RESPONSIVE */
@media (max-width: 640px) {
  .container { padding: 24px 20px 64px; }
  .header { flex-wrap: wrap; gap: 12px; padding: 16px 0 32px; margin-bottom: 32px; }
  .nav { margin-left: 0; width: 100%; gap: 16px; font-size: 11px; }
  .logo-icon { height: 44px; }
  .logo-word { height: 26px; }
  .cards { grid-template-columns: 1fr; }
  .toc { padding: 20px; }
  h2 { font-size: 19px; margin: 36px 0 12px; }
}