.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  padding: 8px 12px;
  border-radius: 999px;
  background: #fff;
  color: #28323a;
  box-shadow: 0 8px 24px rgba(42, 74, 96, .16);
  transform: translateY(-160%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid var(--accent-deep);
  outline-offset: 2px;
}

.nav a {
  position: relative;
  padding-bottom: 4px;
}

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--accent-deep);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 180ms ease;
}

.nav a.is-active {
  color: var(--ink);
}

.nav a.is-active::after {
  transform: scaleX(1);
}

.version-mark {
  color: var(--accent-deep);
}

:focus-visible {
  outline: 2px solid var(--accent-deep);
  outline-offset: 3px;
}

.detail-close:focus-visible,
.content-card:focus-visible,
.mascot-companion:focus-visible,
.soft-button:focus-visible,
.link-row a:focus-visible {
  outline: 2px solid var(--accent-deep);
  outline-offset: 3px;
}

/* =========================================================
   V1 visual direction — closer to the original concept art
   ========================================================= */

:root {
  --concept-blue: #4d86d8;
  --concept-blue-soft: #8bb8ea;
  --concept-ink: #17355f;
  --concept-glass: rgba(248, 252, 255, .62);
  --concept-glass-strong: rgba(251, 253, 255, .78);
  --concept-line: rgba(108, 162, 216, .22);
  --concept-shadow: 0 16px 42px rgba(67, 113, 159, .14);
}

html {
  background: #eaf3f8;
}

body {
  position: relative;
  isolation: isolate;
  background: transparent;
}

.background-layer {
  background:
    linear-gradient(90deg, rgba(235, 247, 255, .78) 0%, rgba(239, 248, 254, .61) 36%, rgba(237, 246, 252, .38) 67%, rgba(239, 247, 252, .58) 100%),
    linear-gradient(rgba(237, 247, 252, .20), rgba(243, 249, 253, .42)),
    url("./assets/background.jpg") center / cover no-repeat;
  filter: saturate(.92) brightness(1.04);
}

.sky-glow {
  background:
    radial-gradient(circle at 7% 12%, rgba(255,255,255,.96), transparent 24%),
    radial-gradient(circle at 24% 58%, rgba(180, 220, 250, .25), transparent 31%),
    radial-gradient(circle at 79% 19%, rgba(255,255,255,.34), transparent 24%),
    linear-gradient(180deg, rgba(216,239,255,.08), rgba(255,255,255,.22));
}

.site-header {
  top: 18px;
  width: min(1240px, calc(100% - 40px));
  margin: 18px auto 0;
  padding: 15px 22px;
  border: 1px solid rgba(255,255,255,.82);
  border-radius: 24px;
  background: rgba(247, 251, 255, .66);
  box-shadow: 0 12px 34px rgba(68, 111, 155, .12);
  backdrop-filter: blur(24px) saturate(1.12);
}

.brand-jp {
  color: var(--concept-ink);
  font-size: 1.28rem;
  letter-spacing: .12em;
}

.brand-en {
  color: rgba(50, 86, 129, .62);
}

.nav {
  gap: 30px;
  color: #37577f;
}

.nav a {
  padding: 8px 13px;
  border-radius: 999px;
  transition: background 180ms ease, color 180ms ease, transform 180ms ease;
}

.nav a::after { display: none; }

.nav a:hover,
.nav a.is-active {
  background: rgba(255,255,255,.72);
  color: var(--concept-blue);
  box-shadow: 0 6px 18px rgba(70, 116, 165, .10);
  transform: translateY(-1px);
}

main {
  width: min(1220px, calc(100% - 40px));
}

.hero {
  min-height: 82vh;
  grid-template-columns: 1.05fr .95fr;
  gap: clamp(30px, 5vw, 76px);
  padding-top: clamp(70px, 9vw, 110px);
  padding-bottom: 74px;
}

.hero-copy {
  padding-left: clamp(6px, 2vw, 24px);
  text-shadow: 0 2px 14px rgba(255,255,255,.82);
}

.eyebrow {
  color: rgba(54, 94, 139, .64);
  letter-spacing: .22em;
}

.hero h1 {
  color: var(--concept-ink);
  font-size: clamp(4.8rem, 9vw, 8.5rem);
  letter-spacing: .045em;
  text-shadow: 0 2px 20px rgba(255,255,255,.92);
}

.subtitle {
  color: #315a8b;
  letter-spacing: .24em;
  margin-top: 16px;
  text-shadow: 0 2px 12px rgba(255,255,255,.88);
}

.quote {
  color: #4f6784;
  line-height: 2;
  max-width: 500px;
}

.soft-button {
  border-color: rgba(88, 144, 208, .28);
  background: rgba(255,255,255,.62);
  color: #315f99;
  box-shadow: 0 8px 20px rgba(76, 123, 170, .10);
}

.soft-button:hover {
  background: rgba(255,255,255,.84);
  box-shadow: 0 12px 24px rgba(76, 123, 170, .16);
}

.hero-status {
  color: rgba(57, 87, 119, .68);
}

.avatar-card {
  width: min(100%, 390px);
  transform: rotate(1deg);
}

.avatar-wrap {
  border-radius: 30px;
  border: 1px solid rgba(255,255,255,.90);
  background: rgba(255,255,255,.54);
  box-shadow: 0 20px 52px rgba(62, 105, 145, .17);
}

.avatar-wrap img {
  object-fit: cover;
  filter: saturate(.94) contrast(.98);
}

.avatar-note {
  color: rgba(55, 88, 121, .65);
  padding-right: 8px;
}

.glass-panel,
.content-card,
.detail-dialog {
  border-color: var(--concept-line);
  background: var(--concept-glass);
  box-shadow: var(--concept-shadow);
  backdrop-filter: blur(26px) saturate(1.08);
}

.glass-panel {
  border-radius: 26px;
}

.section-index,
.card-meta,
.detail-meta {
  color: #6b8fb7;
}

h2 {
  color: var(--concept-ink);
  letter-spacing: .025em;
}

.prose p,
.section-description,
.contact-copy {
  color: #5a6f89;
}

.content-card {
  min-height: 215px;
  border-radius: 21px;
  background: rgba(249, 252, 255, .66);
  box-shadow: 0 10px 28px rgba(75, 118, 159, .09);
}

.content-card:hover:not(.is-disabled),
.content-card:focus-visible:not(.is-disabled) {
  transform: translateY(-5px);
  background: rgba(252,254,255,.86);
  box-shadow: 0 18px 38px rgba(69, 116, 160, .14);
}

.content-card h3 {
  color: #244b7d;
}

.content-card p {
  color: #6b7c90;
}

.card-arrow {
  color: var(--concept-blue);
}

.contact-section {
  margin-top: 30px;
}

.link-row a {
  min-width: 84px;
  border: 1px solid rgba(102, 151, 203, .22);
  border-radius: 12px;
  background: rgba(255,255,255,.46);
  box-shadow: 0 7px 18px rgba(71, 114, 158, .08);
}

.link-row a:hover {
  background: rgba(255,255,255,.78);
}

.detail-dialog {
  background: rgba(248,252,255,.92);
  border-radius: 24px;
}

.mascot-companion {
  width: clamp(92px, 9vw, 124px);
  right: clamp(18px, 3vw, 38px);
  bottom: 16px;
  filter: drop-shadow(0 12px 18px rgba(52, 85, 120, .18));
}

.mascot-bubble {
  border: 1px solid rgba(114, 163, 213, .24);
  background: rgba(249,253,255,.92);
  color: #536f91;
  box-shadow: 0 10px 28px rgba(68, 108, 149, .12);
  backdrop-filter: blur(18px);
}

footer {
  color: rgba(57, 89, 121, .58);
}

@media (max-width: 760px) {
  .version-mark {
    display: none;
  }

  .background-layer {
    background-position: center center;
  }

  .site-header {
    top: 8px;
    width: calc(100% - 18px);
    margin-top: 8px;
    padding: 12px 14px;
    border-radius: 18px;
  }

  main {
    width: min(100% - 22px, 1180px);
  }

  .hero {
    padding-top: 76px;
  }

  .hero-copy {
    padding-left: 4px;
  }

  .hero h1 {
    font-size: clamp(4rem, 21vw, 6.4rem);
  }

  .avatar-card {
    width: min(76vw, 300px);
    margin-right: 2vw;
  }

  .glass-panel,
  .content-card {
    backdrop-filter: blur(20px) saturate(1.05);
  }

  .mascot-companion {
    width: 82px;
    right: 12px;
    bottom: 10px;
  }
}