:root {
  --bg: #f6f7f4;
  --surface: #ffffff;
  --surface-soft: #eef4f3;
  --text: #24302f;
  --muted: #65716f;
  --line: #d8e0dc;
  --accent: #1f6f68;
  --accent-deep: #164c48;
  --accent-soft: #dcecea;
  --gold: #a66f2a;
  --shadow: 0 16px 40px rgba(35, 48, 47, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Meiryo", "Yu Gothic", "Hiragino Kaku Gothic ProN", sans-serif;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
}

a {
  color: var(--accent-deep);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  display: block;
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid var(--line);
  background: rgba(246, 247, 244, 0.94);
  backdrop-filter: blur(14px);
}

.nav {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
}

.brand {
  display: grid;
  color: var(--text);
}

.brand strong {
  font-size: 18px;
  letter-spacing: 0;
}

.brand span {
  font-size: 12px;
  color: var(--muted);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.nav-links a {
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--text);
  font-size: 14px;
}

.nav-links .language-link {
  border: 1px solid var(--line);
  background: var(--surface);
  font-weight: 700;
}

.nav-links a[aria-current="page"],
.nav-links a:hover {
  background: var(--accent-soft);
  text-decoration: none;
}

.hero {
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(110deg, rgba(246, 247, 244, 0.96), rgba(246, 247, 244, 0.68)),
    url("hero-learning.svg") center right / min(680px, 86vw) no-repeat,
    radial-gradient(circle at 82% 38%, rgba(31, 111, 104, 0.22), transparent 32%),
    linear-gradient(135deg, rgba(220, 236, 234, 0.7), rgba(246, 247, 244, 0));
}

.hero-inner {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 540px;
  padding: 82px 0 56px;
  display: grid;
  align-content: center;
  gap: 30px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--gold);
  font-weight: 700;
  font-size: 14px;
}

.hero h1,
.page-title h1 {
  max-width: 860px;
  margin: 0;
  font-size: clamp(32px, 6vw, 64px);
  line-height: 1.18;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 760px;
  margin: 0;
  font-size: 18px;
  color: #3e4d4a;
}

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

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 16px;
  border: 1px solid var(--accent);
  border-radius: 6px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
}

.button.secondary {
  background: transparent;
  color: var(--accent-deep);
}

.button:hover {
  text-decoration: none;
  filter: brightness(0.96);
}

main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.section {
  padding: 56px 0;
}

.section + .section {
  border-top: 1px solid var(--line);
}

.section-head {
  display: grid;
  gap: 10px;
  max-width: 760px;
  margin-bottom: 24px;
}

h2,
h3,
p {
  margin-top: 0;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1.3;
}

h3 {
  margin-bottom: 10px;
  font-size: 19px;
  line-height: 1.45;
}

p {
  margin-bottom: 14px;
}

.lead {
  color: var(--muted);
  font-size: 17px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

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

.card {
  min-width: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.card.compact {
  box-shadow: none;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.tag-list li {
  padding: 6px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: #40504d;
  font-size: 14px;
}

.feature-band {
  margin: 8px 0 0;
  padding: 28px;
  border-radius: 8px;
  background: var(--surface-soft);
}

.page-title {
  padding: 64px 0 34px;
  border-bottom: 1px solid var(--line);
}

.page-title p {
  max-width: 790px;
  color: var(--muted);
  font-size: 18px;
}

.split {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 28px;
  align-items: start;
}

.portrait-placeholder,
.project-visual {
  display: grid;
  place-items: center;
  min-height: 220px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent-soft), #fff);
  color: var(--muted);
  text-align: center;
  padding: 20px;
}

.list {
  margin: 0;
  padding-left: 1.2em;
}

.list li {
  margin-bottom: 8px;
}

.definition-list {
  display: grid;
  gap: 14px;
  margin: 0;
}

.definition-list div {
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.definition-list dt {
  font-weight: 700;
}

.definition-list dd {
  margin: 4px 0 0;
  color: var(--muted);
}

.project-card {
  display: grid;
  grid-template-rows: auto 1fr;
  overflow: hidden;
  padding: 0;
}

.project-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--surface-soft);
}

.project-card .body {
  padding: 20px;
}

.placeholder {
  color: #7a5b2e;
  font-weight: 700;
}

.site-footer {
  margin-top: 48px;
  border-top: 1px solid var(--line);
  background: #edf1ee;
}

.footer-inner {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0;
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 820px) {
  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
    gap: 12px;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .hero-inner {
    min-height: 540px;
    padding-top: 52px;
    align-content: start;
  }

  .grid,
  .grid.two,
  .split {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .nav,
  main,
  .hero-inner,
  .footer-inner {
    width: min(100% - 24px, 1120px);
  }

  .nav-links a {
    padding: 7px 8px;
    font-size: 13px;
  }

  .hero h1,
  .page-title h1 {
    font-size: 31px;
  }

  .hero-copy,
  .page-title p {
    font-size: 16px;
  }

  .section {
    padding: 40px 0;
  }

  .card,
  .feature-band {
    padding: 18px;
  }
}