:root {
  --bg: #fbfdff;
  --bg-soft: #eef8f5;
  --surface: #ffffff;
  --surface-strong: #f8fbff;
  --text: #162235;
  --muted: #475467;
  --line: #d5e3ea;
  --accent: #247994;
  --accent-dark: #174f64;
  --accent-soft: #dff3f8;
  --coral: #e7785f;
  --green: #4d9674;
  --yellow: #f2bd5b;
  --shadow: 0 14px 32px rgba(22, 34, 53, 0.08);
  --radius: 8px;
  --radius-sm: 8px;
  --max-width: 1100px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  font-family: "Yu Gothic", "Hiragino Kaku Gothic ProN", Meiryo, system-ui, sans-serif;
  background:
    radial-gradient(circle at 14% 8%, rgba(226, 247, 250, 0.72), transparent 28rem),
    radial-gradient(circle at 88% 18%, rgba(255, 232, 211, 0.48), transparent 28rem),
    linear-gradient(180deg, var(--bg) 0%, #ffffff 52%, var(--bg-soft) 100%);
  line-height: 1.7;
  overflow-x: hidden;
}

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

a:focus-visible {
  outline: 3px solid rgba(37, 111, 143, 0.28);
  outline-offset: 4px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: 100%;
  margin: 0 auto;
  padding: 18px max(16px, calc((100% - var(--max-width)) / 2));
  background: rgba(247, 251, 255, 0.82);
  backdrop-filter: blur(16px);
}

.site-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 0.98rem;
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
}

.logo-dot {
  width: 14px;
  height: 14px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--coral));
  box-shadow: 0 0 0 5px rgba(37, 111, 143, 0.1);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

.site-nav a {
  border-radius: 999px;
  padding: 9px 13px;
  color: #536176;
  font-size: 0.88rem;
  font-weight: 700;
  transition: background-color 180ms ease, color 180ms ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--accent-dark);
  background: rgba(37, 111, 143, 0.09);
}

.section-shell {
  width: min(var(--max-width), calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  display: grid;
  min-height: min(500px, calc(100vh - 160px));
  padding: 34px 0 36px;
  place-items: center;
}

.hero-content {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 32px;
  align-items: center;
  width: 100%;
}

.avatar-placeholder {
  position: relative;
  display: grid;
  width: 150px;
  aspect-ratio: 1;
  place-items: center;
  border: 1px solid rgba(37, 111, 143, 0.18);
  border-radius: 50%;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.92), rgba(223, 243, 248, 0.78)),
    radial-gradient(circle at 68% 28%, rgba(231, 120, 95, 0.28), transparent 32%);
  box-shadow: var(--shadow);
}

.avatar-placeholder::before,
.avatar-placeholder::after {
  position: absolute;
  content: "";
  border-radius: 50%;
}

.avatar-placeholder::before {
  inset: 22px;
  border: 1px dashed rgba(37, 111, 143, 0.32);
}

.avatar-placeholder::after {
  right: 28px;
  bottom: 34px;
  width: 26px;
  height: 26px;
  background: var(--yellow);
  box-shadow: -86px -64px 0 -5px var(--green);
}

.avatar-placeholder span {
  position: relative;
  z-index: 1;
  color: var(--accent-dark);
  font-size: 1.65rem;
  font-weight: 800;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 780px;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 14px;
  font-size: clamp(2.55rem, 5.8vw, 4.65rem);
  line-height: 1.06;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 760px;
  margin-bottom: 14px;
  color: #1d3148;
  font-size: clamp(1.12rem, 2vw, 1.42rem);
  font-weight: 700;
  line-height: 1.55;
}

.hero-text {
  max-width: 720px;
  margin-bottom: 24px;
  color: var(--muted);
  font-size: 1rem;
}

.no-break {
  white-space: nowrap;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 12px 22px;
  font-size: 0.98rem;
  font-weight: 800;
  transition: transform 180ms ease, box-shadow 180ms ease, background-color 180ms ease;
}

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

.button.primary {
  color: #ffffff;
  background: var(--accent);
  box-shadow: 0 10px 20px rgba(37, 121, 148, 0.2);
}

.button.primary:hover,
.button.primary:focus-visible {
  background: var(--accent-dark);
}

.button.secondary {
  color: var(--accent-dark);
  border-color: rgba(37, 111, 143, 0.18);
  background: rgba(255, 255, 255, 0.76);
}

.button.secondary:hover,
.button.secondary:focus-visible {
  box-shadow: 0 10px 22px rgba(29, 41, 57, 0.08);
}

section + section {
  padding-top: 62px;
}

section[id] {
  scroll-margin-top: 96px;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 28px;
}

.section-heading h2 {
  margin-bottom: 10px;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.16;
  letter-spacing: 0;
}

.section-heading p {
  margin-bottom: 0;
  color: var(--muted);
}

.about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 420px;
  gap: 24px;
  align-items: stretch;
}

.about-text {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px;
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 12px 30px rgba(29, 41, 57, 0.05);
  font-size: 1.06rem;
}

.lane-list {
  display: grid;
  gap: 16px;
}

.lane-card,
.activity-card,
.link-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 10px 24px rgba(22, 34, 53, 0.045);
}

.lane-card {
  padding: 24px;
}

.lane-card h3 {
  margin-bottom: 8px;
  color: var(--accent-dark);
  font-size: 1.02rem;
  letter-spacing: 0;
}

.lane-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.activity-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 18px;
}

.activity-card {
  min-height: auto;
  padding: 22px;
}

.card-mark {
  display: grid;
  width: 46px;
  height: 46px;
  margin-bottom: 22px;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  font-size: 0.88rem;
  font-weight: 900;
}

.card-mark.ai {
  background: var(--accent);
}

.card-mark.art {
  background: var(--coral);
}

.card-mark.study {
  background: var(--green);
}

.card-mark.video {
  background: #354255;
}

.activity-card h3 {
  margin-bottom: 12px;
  font-size: 1.13rem;
  line-height: 1.35;
}

.activity-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.96rem;
}

.building {
  padding-bottom: 4px;
}

.building-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.building-list li {
  position: relative;
  min-height: 58px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 18px 18px 18px 48px;
  background: rgba(255, 255, 255, 0.92);
  color: #26384c;
  font-weight: 700;
}

.building-list li::before {
  position: absolute;
  top: 23px;
  left: 20px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--coral);
  content: "";
}

.links {
  padding-bottom: 96px;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 16px;
}

.link-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  min-height: 108px;
  gap: 14px;
  padding: 18px;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.link-card:hover,
.link-card:focus-visible {
  border-color: rgba(37, 111, 143, 0.35);
  box-shadow: 0 16px 34px rgba(29, 41, 57, 0.08);
  transform: translateY(-3px);
}

.link-card.coming-soon {
  cursor: default;
}

.link-card.coming-soon:hover,
.link-card.coming-soon:focus-visible {
  border-color: var(--line);
  box-shadow: 0 12px 30px rgba(29, 41, 57, 0.05);
  transform: none;
}

.link-icon {
  display: grid;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  background: var(--accent);
  font-size: 0.92rem;
  font-weight: 900;
}

.link-card-text {
  display: grid;
  min-width: 0;
  gap: 4px;
}

.link-title {
  font-size: 1.03rem;
  font-weight: 800;
  line-height: 1.35;
  overflow-wrap: break-word;
  word-break: normal;
  white-space: normal;
}

.link-card small {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  overflow-wrap: break-word;
  word-break: normal;
}

.link-arrow {
  color: rgba(24, 85, 111, 0.56);
  font-size: 1rem;
  font-weight: 900;
}

.link-status {
  grid-column: 2;
  justify-self: end;
  border: 1px solid rgba(37, 111, 143, 0.18);
  border-radius: 999px;
  padding: 5px 8px;
  color: var(--accent-dark);
  background: rgba(223, 243, 248, 0.56);
  font-size: 0.7rem;
  font-weight: 800;
  line-height: 1;
  white-space: nowrap;
}

.link-card.muted {
  background: rgba(248, 251, 255, 0.88);
}

.link-card.muted .link-icon {
  color: var(--accent-dark);
  background: var(--accent-soft);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  width: min(var(--max-width), calc(100% - 32px));
  margin: 0 auto;
  border-top: 1px solid var(--line);
  padding: 28px 0 34px;
  color: var(--muted);
  font-size: 0.92rem;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

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

  .hero {
    min-height: auto;
    padding-top: 36px;
  }

  .hero-content,
  .about-grid {
    grid-template-columns: 1fr;
  }

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

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

@media (max-width: 640px) {
  .section-shell,
  .site-footer {
    width: min(100% - 24px, var(--max-width));
  }

  .site-header {
    position: static;
    gap: 12px;
    padding: 14px 12px;
  }

  .site-nav {
    display: grid;
    width: 100%;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
  }

  .site-nav a {
    padding: 8px 6px;
    font-size: 0.78rem;
    text-align: center;
  }

  .hero {
    padding: 28px 0 38px;
  }

  .hero-content {
    gap: 24px;
  }

  .avatar-placeholder {
    width: 138px;
  }

  h1 {
    font-size: clamp(2.1rem, 10vw, 2.75rem);
    line-height: 1.08;
  }

  .hero-lead {
    font-size: 1.06rem;
    line-height: 1.65;
  }

  .hero-text {
    font-size: 0.98rem;
  }

  .hero-actions {
    width: 100%;
    max-width: 340px;
  }

  .button {
    min-height: 52px;
    width: 100%;
  }

  section + section {
    padding-top: 48px;
  }

  .about-text,
  .lane-card,
  .activity-card {
    padding: 20px;
  }

  .activity-grid,
  .building-list,
  .link-grid {
    grid-template-columns: 1fr;
  }

  .activity-card {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: 14px;
    align-items: start;
    min-height: auto;
  }

  .activity-card .card-mark {
    margin-bottom: 0;
  }

  .activity-card h3 {
    margin-bottom: 6px;
  }

  .activity-card p {
    grid-column: 1 / -1;
    margin-top: 12px;
  }

  .building-list li {
    min-height: 58px;
    padding: 16px 16px 16px 42px;
  }

  .building-list li::before {
    top: 22px;
    left: 18px;
  }

  .link-card {
    min-height: auto;
    padding: 16px;
  }

  .link-card.pending-url,
  .link-card.coming-soon {
    grid-template-columns: auto minmax(0, 1fr);
  }

  .link-status {
    grid-column: 2;
    justify-self: start;
  }

  .link-icon {
    width: 38px;
    height: 38px;
  }

  .links {
    padding-bottom: 72px;
  }
}

@media (max-width: 430px) {
  .site-logo {
    font-size: 0.94rem;
  }

  .avatar-placeholder {
    width: 128px;
  }

  .hero-actions {
    max-width: 100%;
  }
}

@media (max-width: 390px) {
  .section-shell,
  .site-footer {
    width: min(100% - 20px, var(--max-width));
  }

  .site-header {
    padding: 12px 10px;
  }

  .site-nav a {
    font-size: 0.76rem;
  }

  h1 {
    font-size: 2.05rem;
  }

  .hero-lead {
    font-size: 1rem;
  }

  .hero-text,
  .activity-card p,
  .about-text {
    font-size: 0.94rem;
  }

  .link-card {
    gap: 12px;
    padding: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}