:root {
  --bg: #0b1220;
  --bg-soft: #111b2e;
  --surface: #ffffff;
  --surface-soft: #f5f7fb;
  --text: #111827;
  --text-soft: #5d6675;
  --text-inverse: #f8fafc;
  --text-inverse-soft: #a9b5c7;
  --line: #dfe5ee;
  --line-dark: rgba(255, 255, 255, 0.12);
  --accent: #5eead4;
  --accent-dark: #0f766e;
  --max-width: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--surface);
  font-family:
    Inter, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic",
    Meiryo, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.container {
  width: min(calc(100% - 40px), var(--max-width));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(11, 18, 32, 0.92);
  border-bottom: 1px solid var(--line-dark);
  backdrop-filter: blur(16px);
}

.header-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: var(--text-inverse);
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.nav {
  display: flex;
  gap: 28px;
  align-items: center;
}

.nav a {
  color: var(--text-inverse-soft);
  font-size: 0.9rem;
  transition: color 0.2s ease;
}

.nav a:hover {
  color: var(--accent);
}

.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 84% 20%, rgba(94, 234, 212, 0.13), transparent 28rem),
    radial-gradient(circle at 18% 85%, rgba(59, 130, 246, 0.12), transparent 26rem),
    var(--bg);
  color: var(--text-inverse);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black, transparent 90%);
}

.hero-grid {
  position: relative;
  z-index: 1;
  min-height: 560px;
  padding: 72px 0;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(280px, 0.75fr);
  gap: 64px;
  align-items: center;
}

.eyebrow,
.section-kicker {
  margin: 0 0 18px;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.18em;
}

.eyebrow {
  color: var(--accent);
}

.hero h1 {
  margin: 0;
  max-width: 720px;
  font-size: clamp(3rem, 6vw, 5rem);
  line-height: 1.08;
  letter-spacing: -0.055em;
}

.lead {
  max-width: 660px;
  margin: 24px 0 0;
  color: var(--text-inverse-soft);
  font-size: clamp(1rem, 1.6vw, 1.12rem);
}

.hero-actions {
  margin-top: 30px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  min-height: 48px;
  padding: 0 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 10px;
  font-size: 0.92rem;
  font-weight: 750;
  transition:
    transform 0.2s ease,
    border-color 0.2s ease,
    background-color 0.2s ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: #052e2b;
  background: var(--accent);
}

.button.primary:hover {
  background: #99f6e4;
}

.button.secondary {
  color: var(--text-inverse);
  border-color: var(--line-dark);
  background: rgba(255, 255, 255, 0.05);
}

.button.secondary:hover {
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.09);
}

.profile-card {
  padding: 24px;
  border: 1px solid var(--line-dark);
  border-radius: 20px;
  background: rgba(17, 27, 46, 0.82);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.22);
}

.avatar {
  width: 76px;
  height: 76px;
  border: 3px solid rgba(255, 255, 255, 0.12);
  border-radius: 50%;
  object-fit: cover;
}

.profile-name {
  margin: 16px 0 4px;
  font-size: 1.14rem;
  font-weight: 800;
}

.profile-text {
  margin: 0;
  color: var(--text-inverse-soft);
  font-size: 0.91rem;
}

.profile-links {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line-dark);
  display: grid;
  gap: 10px;
}

.profile-links a {
  color: var(--text-inverse-soft);
  font-size: 0.86rem;
}

.profile-links a:hover {
  color: var(--accent);
}

.section {
  padding: 92px 0;
}

.section-heading {
  margin-bottom: 42px;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
}

.section-kicker {
  color: var(--accent-dark);
}

.section h2 {
  margin: 0;
  font-size: clamp(2.1rem, 4vw, 3.5rem);
  line-height: 1.13;
  letter-spacing: -0.045em;
}

.text-link {
  color: var(--text-soft);
  font-size: 0.9rem;
  font-weight: 700;
}

.text-link:hover {
  color: var(--accent-dark);
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.project-card {
  min-height: 245px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
  display: flex;
  flex-direction: column;
  transition:
    transform 0.2s ease,
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: #b6c3d4;
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
}

.project-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.tag {
  padding: 5px 9px;
  border-radius: 999px;
  color: #0f766e;
  background: #e6fffb;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.arrow {
  color: #94a3b8;
  font-size: 1.25rem;
}

.project-card h3 {
  margin: 34px 0 10px;
  font-size: 1.12rem;
  line-height: 1.4;
  letter-spacing: -0.02em;
}

.project-card p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.9rem;
}

.section-muted {
  background: var(--surface-soft);
}

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 90px;
  align-items: start;
}

.about-copy > p {
  margin: 4px 0 26px;
  color: var(--text-soft);
  font-size: 1rem;
}

.about-copy strong {
  color: var(--text);
}

.topic-list {
  margin: 0 0 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.topic-list span {
  padding: 8px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: #475569;
  font-size: 0.82rem;
  font-weight: 700;
}

.about-copy .button.primary {
  color: var(--text-inverse);
  background: var(--bg);
}

.about-copy .button.primary:hover {
  background: #1e293b;
}

.site-footer {
  padding: 28px 0;
  color: var(--text-inverse-soft);
  background: var(--bg);
  border-top: 1px solid var(--line-dark);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
}

.footer-inner p {
  margin: 0;
  font-size: 0.82rem;
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  font-size: 0.82rem;
}

.footer-links a:hover {
  color: var(--accent);
}

@media (max-width: 900px) {
  .hero-grid {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 44px;
    padding: 72px 0;
  }

  .profile-card {
    max-width: 520px;
  }

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

  .about-grid {
    grid-template-columns: 1fr;
    gap: 42px;
  }
}

@media (max-width: 640px) {
  .container {
    width: min(calc(100% - 28px), var(--max-width));
  }

  .header-inner {
    min-height: 62px;
  }

  .nav {
    gap: 14px;
  }

  .nav a {
    font-size: 0.78rem;
  }

  .nav a:nth-child(1),
  .nav a:nth-child(2) {
    display: none;
  }

  .hero-grid {
    padding: 56px 0 64px;
  }

  .hero h1 {
    font-size: clamp(2.8rem, 14vw, 4rem);
    line-height: 1.08;
  }

  .lead {
    margin-top: 24px;
  }

  .hero-actions {
    display: grid;
  }

  .button {
    width: 100%;
  }

  .section {
    padding: 72px 0;
  }

  .section-heading {
    align-items: start;
    flex-direction: column;
  }

  .project-grid {
    grid-template-columns: 1fr;
  }

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

  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }
}