:root {
  --bg: #0e171f;
  --bg-soft: #132633;
  --ink: #eaf2f7;
  --ink-dim: #b6c6d2;
  --line: #2f495e;
  --brand: #00d3a7;
  --brand-strong: #00a786;
  --accent: #ff9f43;
  --status: #155799;
  --card: rgba(18, 38, 52, 0.76);
  --shadow: 0 14px 36px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  color: var(--ink);
  background: radial-gradient(circle at 20% 0%, #1d3a4e 0%, var(--bg) 38%, #0a1117 100%);
  font-family: "Chakra Petch", sans-serif;
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 30px 30px;
  mask-image: radial-gradient(circle at center, black 34%, transparent 95%);
  pointer-events: none;
  z-index: 0;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 6vw;
  backdrop-filter: blur(10px);
  background: rgba(9, 20, 28, 0.72);
  border-bottom: 1px solid var(--line);
}

.logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-weight: 700;
  letter-spacing: 0.08em;
  background: linear-gradient(135deg, var(--brand), #66ffe2);
  color: #042118;
}

.topbar nav {
  display: flex;
  gap: 18px;
}

.topbar a {
  color: var(--ink);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
}

.topbar a:hover {
  color: var(--brand);
}

main {
  position: relative;
  z-index: 1;
  max-width: 1120px;
  margin: 0 auto;
  padding: 28px 6vw 70px;
}

.hero {
  padding: 48px 0 12px;
}

.eyebrow {
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 700;
  margin: 0;
}

h1 {
  margin: 10px 0 14px;
  font-size: clamp(2.1rem, 5.5vw, 4rem);
  line-height: 1.06;
}

.alpha-badge {
  display: inline-block;
  vertical-align: middle;
  margin-left: 10px;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.38em;
  letter-spacing: 0.12em;
  line-height: 1.1;
  background: linear-gradient(135deg, #ffb35a, #ff7d42);
  color: #2c1200;
  border: 1px solid rgba(255, 214, 170, 0.65);
}

.subtitle {
  max-width: 740px;
  color: var(--ink-dim);
  font-size: 1.08rem;
  line-height: 1.55;
}

.warning-note {
  margin: 14px 0 0;
  display: inline-block;
  border: 1px solid #8a5927;
  background: rgba(138, 89, 39, 0.2);
  color: #ffd8a8;
  padding: 8px 12px;
  border-radius: 10px;
}

.cta-row {
  margin-top: 22px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 10px 16px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 700;
  transition: transform 150ms ease, box-shadow 150ms ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--brand), #58fddf);
  color: #052a20;
  box-shadow: 0 8px 20px rgba(0, 211, 167, 0.27);
}

.btn-ghost {
  border: 1px solid var(--line);
  color: var(--ink);
}

.terminal-glimpse {
  margin-top: 28px;
  border: 1px solid #214358;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: var(--shadow);
  background: #0b1218;
}

.terminal-top {
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid #1f3544;
  padding: 9px 14px;
  font-size: 0.82rem;
  color: #98b4c4;
}

.terminal-top span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #335769;
}

.terminal-top span:nth-child(1) {
  background: #ff7f7f;
}

.terminal-top span:nth-child(2) {
  background: #ffd166;
}

.terminal-top span:nth-child(3) {
  background: #56f59c;
}

.terminal-glimpse pre {
  margin: 0;
  padding: 16px;
  font-family: "IBM Plex Mono", monospace;
  color: #96ffc2;
  white-space: pre-wrap;
}

.panel {
  margin-top: 32px;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px;
  background: var(--card);
  box-shadow: var(--shadow);
}

.panel h2 {
  margin: 0 0 10px;
  font-size: 1.7rem;
}

.card-grid {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.card {
  border: 1px solid #365163;
  border-radius: 12px;
  padding: 14px;
  background: rgba(14, 28, 37, 0.74);
}

.card h3 {
  margin: 0 0 8px;
}

.card p {
  margin: 0;
  color: var(--ink-dim);
  line-height: 1.45;
}

.mono {
  font-family: "IBM Plex Mono", monospace;
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.code-box {
  border: 1px solid #395366;
  border-radius: 12px;
  padding: 14px;
  background: rgba(10, 20, 28, 0.78);
}

.code-box h3 {
  margin-top: 0;
}

.code-box pre {
  margin: 0;
  overflow-x: auto;
  font-family: "IBM Plex Mono", monospace;
  color: #d2f4ff;
}

.accent {
  border-color: #8a5927;
  background: linear-gradient(120deg, rgba(28, 42, 53, 0.84) 0%, rgba(51, 37, 22, 0.72) 100%);
}

.panel ul {
  margin: 10px 0 18px 20px;
  color: var(--ink-dim);
}

.timeline {
  display: grid;
  gap: 12px;
}

.point {
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.point span {
  margin-top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brand);
  box-shadow: 0 0 0 4px rgba(0, 211, 167, 0.18);
}

.point p {
  margin: 0;
  color: var(--ink-dim);
}

.doc-grid {
  margin-top: 10px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.doc-card {
  border: 1px solid #365163;
  border-radius: 12px;
  padding: 14px;
  background: rgba(12, 26, 35, 0.78);
}

.doc-card h3 {
  margin: 0 0 8px;
}

.doc-card p {
  margin: 0;
  color: var(--ink-dim);
  line-height: 1.45;
}

.doc-list {
  margin: 0 0 14px 20px;
  color: var(--ink-dim);
  line-height: 1.5;
}

.doc-list li {
  margin-bottom: 8px;
}

.doc-table {
  width: 100%;
  border-collapse: collapse;
  overflow: hidden;
  border-radius: 10px;
  border: 1px solid #365163;
}

.doc-table th,
.doc-table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid #2f4658;
}

.doc-table thead th {
  color: #d9f8ee;
  background: rgba(19, 49, 65, 0.76);
}

.doc-table tbody td {
  color: var(--ink-dim);
  background: rgba(10, 21, 28, 0.5);
}

.doc-table tbody tr:last-child td {
  border-bottom: none;
}

.diagram-wrap {
  margin-top: 12px;
  border: 1px solid #365163;
  border-radius: 12px;
  background: rgba(10, 20, 28, 0.78);
  padding: 10px;
}

.arch-diagram {
  width: 100%;
  height: auto;
  display: block;
}

.d-shell {
  fill: rgba(11, 24, 33, 0.9);
  stroke: #35556a;
  stroke-width: 1.5;
}

.d-box {
  stroke-width: 1.6;
}

.d-boot {
  fill: rgba(0, 168, 132, 0.16);
  stroke: #2fd8b3;
}

.d-core {
  fill: rgba(255, 159, 67, 0.14);
  stroke: #ffb562;
}

.d-display {
  fill: rgba(79, 172, 254, 0.14);
  stroke: #84c8ff;
}

.d-int {
  fill: rgba(254, 202, 87, 0.14);
  stroke: #ffd87c;
}

.d-io {
  fill: rgba(255, 107, 129, 0.14);
  stroke: #ff9ab0;
}

.d-user {
  fill: rgba(139, 233, 253, 0.12);
  stroke: #9ee7ff;
}

.d-title {
  font-family: "Chakra Petch", sans-serif;
  font-size: 23px;
  font-weight: 700;
  fill: #eaf7ff;
}

.d-text {
  font-family: "IBM Plex Mono", monospace;
  font-size: 16px;
  fill: #b4d2e1;
}

.d-arrow {
  stroke: #9ee7ff;
  stroke-width: 2.1;
}

.d-arrow-warm {
  stroke: #ffd8a0;
  stroke-width: 2.1;
}

footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line);
  margin-top: 34px;
  padding: 18px 6vw 24px;
  color: #9db5c2;
}

.reveal {
  opacity: 0;
  transform: translateY(12px);
  animation: rise-in 580ms ease forwards;
}

.stagger > * {
  opacity: 0;
  transform: translateY(10px);
  animation: rise-in 560ms ease forwards;
}

.stagger > :nth-child(1) { animation-delay: 60ms; }
.stagger > :nth-child(2) { animation-delay: 140ms; }
.stagger > :nth-child(3) { animation-delay: 220ms; }
.stagger > :nth-child(4) { animation-delay: 300ms; }
.stagger > :nth-child(5) { animation-delay: 380ms; }

@keyframes rise-in {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 860px) {
  .card-grid,
  .split,
  .doc-grid {
    grid-template-columns: 1fr;
  }

  .d-title {
    font-size: 20px;
  }

  .d-text {
    font-size: 14px;
  }

  .d-arrow,
  .d-arrow-warm {
    stroke-width: 1.8;
  }

  .topbar {
    flex-wrap: wrap;
    gap: 10px;
  }

  .topbar nav {
    flex-wrap: wrap;
    gap: 12px;
  }
}

@media (max-width: 520px) {
  .hero {
    padding-top: 30px;
  }

  h1 {
    font-size: 2rem;
  }

  .panel {
    padding: 16px;
  }

  .d-title {
    font-size: 17px;
  }

  .d-text {
    font-size: 12px;
  }

  .diagram-wrap {
    padding: 6px;
  }
}