:root {
  --bg-white: #ffffff;
  --bg-gray: #f3f3f3;
  --text: #1f1f1f;
  --muted: #666666;
  --line: #dddddd;
  --accent: #2d2d2d;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg-white);
  line-height: 1.7;
}

a { color: inherit; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.95);
}

.nav-shell {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0.85rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
}

.brand { font-weight: 700; }

.tabs {
  display: flex;
  gap: 0.45rem;
  flex-wrap: wrap;
}

.tabs a {
  padding: 0.32rem 0.72rem;
  border-radius: 999px;
  text-decoration: none;
  color: var(--muted);
  font-weight: 600;
}

.tabs a:hover {
  color: var(--text);
  background: #efefef;
}

.section-block {
  padding: 2.2rem 0;
  border-bottom: 1px solid var(--line);
}

.section-light { background: var(--bg-white); }
.section-gray { background: var(--bg-gray); }

.content-wrap {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1rem;
}

.intro-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 1.5rem;
  align-items: start;
}

.hero-photo {
  width: 100%;
  max-width: 200px;
  aspect-ratio: 1;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #fafafa;
}

h1 {
  margin: 0;
  font-size: clamp(2rem, 3.4vw, 2.5rem);
  line-height: 1.2;
}

h2 {
  margin: 0 0 0.65rem;
  font-size: 1.45rem;
}

.subtitle {
  margin: 0.2rem 0 0.8rem;
  color: var(--muted);
}

.note {
  color: var(--muted);
  margin-top: 0.8rem;
}

.cta-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.button {
  text-decoration: none;
  padding: 0.45rem 0.88rem;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fff;
  font-weight: 600;
}

.button.primary {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
}

ol, ul { padding-left: 1.2rem; }
li + li { margin-top: 0.62rem; }
ul ul { margin-top: 0.5rem; }

@media (max-width: 850px) {
  .intro-grid { grid-template-columns: 1fr; }
  .hero-photo { max-width: 170px; }
}