:root {
  color-scheme: dark;
  --bg: #05070d;
  --panel: rgba(12, 18, 30, 0.92);
  --panel-strong: rgba(17, 27, 44, 0.96);
  --line: rgba(147, 197, 253, 0.2);
  --text: #f7fbff;
  --muted: #aeb9c9;
  --blue: #58b7ff;
  --cyan: #5eead4;
  --gold: #f1d27a;
  --coral: #ff8a80;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.38);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bg);
}

body {
  min-height: 100%;
  margin: 0;
  overflow-x: hidden;
  color: var(--text);
  font-family: "Zen Kaku Gothic Antique", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.75;
  letter-spacing: 0;
}

a {
  color: inherit;
}

.desktop-bg {
  position: fixed;
  inset: 0;
  background:
    linear-gradient(135deg, rgba(9, 15, 27, 0.74), rgba(5, 7, 13, 0.95)),
    url("https://aoi-ei.com/wp-content/uploads/2026/04/aoi-ei-cover-1536x864.webp") center / cover no-repeat;
  z-index: -2;
}

.desktop-bg::after {
  position: absolute;
  inset: 0;
  content: "";
  background: radial-gradient(circle at 50% 20%, rgba(88, 183, 255, 0.18), transparent 42%);
  z-index: -1;
}

.shell {
  width: min(1220px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
}

.workspace {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(180deg, rgba(7, 12, 22, 0.93), rgba(8, 13, 23, 0.98));
  box-shadow: var(--shadow);
}

.brand-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 22px;
  border-bottom: 1px solid rgba(147, 197, 253, 0.15);
  background: rgba(1, 7, 16, 0.74);
}

.brand-logo {
  display: inline-flex;
  align-items: center;
  min-width: 130px;
}

.brand-logo img {
  width: 124px;
  height: auto;
  display: block;
}

.brand-strip p {
  margin: 0;
  color: var(--gold);
  font-size: 0.95rem;
  font-weight: 700;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  gap: 28px;
  align-items: stretch;
  padding: 42px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--cyan);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(2.35rem, 5.2vw, 5.4rem);
  line-height: 1.05;
  letter-spacing: 0;
}

h1 span {
  display: block;
}

h2 {
  margin-bottom: 10px;
  font-size: 1.25rem;
  line-height: 1.35;
  letter-spacing: 0;
}

.lead {
  max-width: 720px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: 1.06rem;
}

.quick-nav {
  display: grid;
  gap: 12px;
  align-content: center;
}

.quick-nav a,
.tool-card a {
  text-decoration: none;
}

.quick-nav a {
  display: grid;
  gap: 4px;
  padding: 18px;
  border: 1px solid rgba(94, 234, 212, 0.2);
  border-radius: 8px;
  background: var(--panel);
}

.quick-nav span,
.route-panel span,
.tool-card p,
.note-band p {
  color: var(--muted);
}

.quick-nav strong {
  color: var(--text);
  font-size: 1.12rem;
}

.route-panel {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(147, 197, 253, 0.13);
}

.route-panel div {
  min-height: 118px;
  padding: 20px;
  background: rgba(8, 14, 25, 0.94);
}

.route-panel span,
.route-panel strong {
  display: block;
}

.route-panel strong {
  margin-top: 8px;
  color: var(--gold);
  font-size: 1.06rem;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  padding: 42px;
}

.tool-card {
  display: flex;
  min-height: 250px;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
  padding: 24px;
  border: 1px solid rgba(147, 197, 253, 0.18);
  border-radius: 8px;
  background: var(--panel);
}

.tool-card.featured {
  border-color: rgba(94, 234, 212, 0.32);
  background: linear-gradient(145deg, rgba(13, 34, 52, 0.98), rgba(14, 20, 34, 0.94));
}

.tool-card p {
  margin-bottom: 0;
}

.tool-card a {
  display: inline-flex;
  width: fit-content;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--blue);
  color: #06111f;
  font-weight: 700;
}

.tool-card:nth-child(2) a {
  background: var(--cyan);
}

.tool-card:nth-child(3) a {
  background: var(--gold);
}

.tool-card:nth-child(4) a {
  background: var(--coral);
}

.note-band {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 24px;
  align-items: center;
  padding: 32px 42px 38px;
  border-top: 1px solid var(--line);
  background: rgba(3, 8, 16, 0.72);
}

.note-band p {
  margin-bottom: 0;
}

@media (max-width: 860px) {
  .shell {
    width: calc(100% - 20px);
    max-width: 680px;
    padding-top: 10px;
  }

  .hero,
  .tool-grid,
  .note-band {
    grid-template-columns: 1fr;
    padding: 26px 18px;
  }

  .route-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .route-panel div {
    min-height: 104px;
    padding: 16px;
  }

  h1 {
    font-size: 2.28rem;
    line-height: 1.12;
  }

  .lead {
    max-width: 18em;
  }
}

@media (max-width: 520px) {
  .brand-strip {
    align-items: flex-start;
    flex-direction: column;
  }

  .route-panel,
  .tool-grid {
    grid-template-columns: 1fr;
  }

  .tool-card {
    min-height: 220px;
  }
}