:root {
  --bg: #0b1020;
  --bg-soft: #111936;
  --surface: #151d3d;
  --surface-2: #1c2650;
  --border: #2a3565;
  --text: #e8ecf8;
  --text-dim: #a5b0d0;
  --primary: #6c8cff;
  --primary-strong: #8aa3ff;
  --accent: #ff9f5a;
  --green: #4ade80;
  --red: #f87171;
  --radius: 12px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP", Meiryo, system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

a {
  color: var(--primary-strong);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Nav ---------- */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 20px;
  padding-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
}

.brand:hover {
  text-decoration: none;
}

.brand-logo {
  width: 30px;
  height: 30px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.92rem;
}

.nav-links > a:not(.btn) {
  color: var(--text-dim);
}

.nav-links > a:not(.btn):hover {
  color: var(--text);
}

/* ---------- Hero ---------- */
.hero {
  background:
    radial-gradient(1000px 500px at 85% -10%, rgba(108, 140, 255, 0.25), transparent 60%),
    radial-gradient(700px 400px at 5% 20%, rgba(255, 159, 90, 0.12), transparent 60%),
    linear-gradient(180deg, var(--bg) 0%, #0d1430 100%);
  border-bottom: 1px solid var(--border);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  padding-top: 56px;
  padding-bottom: 72px;
}

.badge {
  display: inline-block;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 0.78rem;
  padding: 4px 12px;
  border-radius: 999px;
  margin-bottom: 18px;
}

.hero-title {
  font-size: 2.8rem;
  margin: 0 0 8px;
  line-height: 1.2;
  letter-spacing: 0.5px;
}

.hero-tagline {
  font-size: 1.25rem;
  color: var(--primary-strong);
  margin: 0 0 14px;
  font-weight: 600;
}

.hero-desc {
  color: var(--text-dim);
  margin: 0 0 26px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.hero-img {
  width: 100%;
  max-width: 460px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
}

.btn:hover {
  text-decoration: none;
  filter: brightness(1.08);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
}

.btn-secondary {
  background: var(--surface-2);
  color: var(--text);
  border-color: var(--border);
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}

.btn-small {
  padding: 6px 14px;
  font-size: 0.85rem;
}

.btn-disabled {
  background: var(--surface-2);
  color: var(--red);
  border-color: var(--border);
  cursor: not-allowed;
  opacity: 0.7;
}

/* ---------- Sections ---------- */
.section {
  padding: 56px 0 8px;
}

.section-title {
  font-size: 1.6rem;
  margin: 0 0 18px;
}

.section-body {
  color: var(--text-dim);
  margin: 0 0 14px;
}

.section-body code {
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 6px;
  font-size: 0.88em;
}

/* ---------- Cards ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 20px;
  margin-top: 8px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
}

.card-head {
  display: flex;
  align-items: center;
  gap: 10px;
}

.card-icon {
  font-size: 1.4rem;
}

.card-title {
  margin: 0;
  font-size: 1.08rem;
}

.card-desc {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.92rem;
  flex: 1;
}

.card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- Tags ---------- */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.tag {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
  border-radius: 999px;
  font-size: 0.76rem;
  padding: 2px 10px;
}

.tag-large {
  font-size: 0.88rem;
  padding: 6px 16px;
}

.stack-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

/* ---------- Code ---------- */
.code-block {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  overflow-x: auto;
  margin: 0 0 18px;
}

.code-block pre {
  margin: 0;
}

.code-block code {
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 0.9rem;
  color: var(--green);
}

/* ---------- Resources ---------- */
.resource-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.resource-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

.resource-list li:last-child {
  border-bottom: none;
}

/* ---------- Feature page ---------- */
.feature-banner {
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-color: var(--primary);
  background:
    radial-gradient(500px 200px at 90% 0%, rgba(108, 140, 255, 0.15), transparent 60%),
    var(--surface);
}

.feature-banner .section-title {
  margin-bottom: 6px;
}

.feature-banner .section-body {
  margin-bottom: 0;
}

@media (max-width: 760px) {
  .feature-banner {
    flex-direction: column;
    align-items: flex-start;
  }
}

.hero-compact .hero-inner {
  grid-template-columns: 1fr;
  padding-top: 40px;
  padding-bottom: 48px;
}

.hero-compact .hero-title {
  font-size: 2.2rem;
}

.section-note {
  color: var(--text-dim);
  font-size: 0.85rem;
  border-left: 3px solid var(--accent);
  padding: 4px 12px;
  margin: 8px 0 0;
}

.grid-4 {
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
}

/* ---------- Timeline ---------- */
.timeline-wrap {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 24px 28px;
  margin-top: 8px;
}

.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
}

.timeline-item {
  position: relative;
  padding: 0 0 22px 40px;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--border);
}

.timeline-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 4px;
}

.timeline-time {
  font-family: "SF Mono", "Menlo", "Consolas", monospace;
  font-size: 0.9rem;
  color: var(--primary-strong);
  font-weight: 600;
}

.timeline-source {
  color: var(--text-dim);
  font-size: 0.82rem;
}

.timeline-cat {
  color: #0b1020;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 1px 10px;
  border-radius: 999px;
}

.timeline-content {
  color: var(--text);
  font-size: 0.95rem;
}

/* ---------- Footer ---------- */
.footer {
  margin-top: 72px;
  border-top: 1px solid var(--border);
  padding: 24px 0;
  color: var(--text-dim);
  font-size: 0.9rem;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

/* ---------- Responsive ---------- */
@media (max-width: 760px) {
  .hero-inner {
    grid-template-columns: 1fr;
    padding-top: 32px;
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .nav-links {
    width: 100%;
    flex-wrap: wrap;
    gap: 10px;
  }
}