/* ===== Design tokens ===== */
:root {
  --bg: #0b0d10;
  --bg-elev: #14171c;
  --bg-card: #161a20;
  --border: #242a33;
  --text: #e6e9ee;
  --text-dim: #9aa4b2;
  --accent: #5eead4;       /* teal */
  --accent-2: #818cf8;     /* indigo */
  --radius: 14px;
  --maxw: 880px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans",
          "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
}

/* ===== Reset / base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Subtle ambient glow */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(600px 400px at 75% -10%, rgba(129, 140, 248, 0.12), transparent 60%),
    radial-gradient(700px 500px at 10% 10%, rgba(94, 234, 212, 0.10), transparent 60%);
  pointer-events: none;
}

a { color: inherit; text-decoration: none; }
.accent {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ===== Navigation ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 18px 24px;
  backdrop-filter: blur(10px);
}
.nav__logo {
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 1.05rem;
}
.nav__logo-mark { color: var(--accent); }
.nav__links { display: flex; gap: 22px; }
.nav__links a {
  color: var(--text-dim);
  font-size: 0.92rem;
  transition: color 0.2s ease;
}
.nav__links a:hover { color: var(--text); }

/* ===== Layout ===== */
main { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

.section { padding: 80px 0; }
.section__title {
  font-size: 1.6rem;
  margin-bottom: 32px;
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.section__num {
  font-size: 0.95rem;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

/* ===== Hero ===== */
.hero { padding: 90px 0 70px; }
.hero__eyebrow {
  color: var(--accent);
  font-size: 0.95rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 18px;
}
.hero__title {
  font-size: clamp(2rem, 6vw, 3.4rem);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 24px;
}
.hero__lead {
  color: var(--text-dim);
  max-width: 620px;
  font-size: 1.05rem;
  margin-bottom: 36px;
}
.hero__cta { display: flex; gap: 14px; flex-wrap: wrap; }

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: transform 0.15s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.btn--primary {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #0b0d10;
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(94,234,212,0.25); }
.btn--ghost {
  border: 1px solid var(--border);
  color: var(--text);
}
.btn--ghost:hover { border-color: var(--accent); transform: translateY(-2px); }

/* ===== About ===== */
.about p { color: var(--text-dim); margin-bottom: 16px; max-width: 680px; }

/* ===== Skills ===== */
.skills {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 24px;
}
.skill-group h3 {
  font-size: 1rem;
  margin-bottom: 14px;
  color: var(--text);
}
.tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; }
.tags li {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 0.85rem;
}
.tags--sm li { padding: 4px 10px; font-size: 0.78rem; }

/* ===== Projects ===== */
.projects {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--accent); }
.card__title { font-size: 1.15rem; }
.card__desc { color: var(--text-dim); font-size: 0.92rem; flex-grow: 1; }
.card__links { display: flex; gap: 16px; margin-top: 4px; }
.card__links a {
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 600;
}
.card__links a:hover { text-decoration: underline; }

/* ===== Contact ===== */
.section--contact { text-align: center; padding-bottom: 100px; }
.section--contact .section__title { justify-content: center; }
.contact__lead { color: var(--text-dim); margin-bottom: 28px; }
.contact__links { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 36px 24px;
  border-top: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* ===== Reveal animation ===== */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ===== Responsive ===== */
@media (max-width: 560px) {
  .nav__links { gap: 14px; }
  .nav__links a { font-size: 0.85rem; }
  .section { padding: 60px 0; }
}