:root {
  --bg: #0e2c3c;
  --panel: #153a4a;
  --panel-strong: #102c38;
  --accent: #57c0d4;
  --accent-hi: #9be2f1;
  --text: #f5f5f5;
  --muted: #c7d8de;
  --shadow: 0 18px 40px rgba(0, 0, 0, 0.18);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top, rgba(87, 192, 212, 0.16), transparent 32rem),
    linear-gradient(180deg, #0b2531 0%, var(--bg) 30%, #0b2531 100%);
  min-height: 100vh;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 0.2rem;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

a:hover {
  color: var(--accent-hi);
  border-bottom-color: var(--accent-hi);
}

a:focus-visible {
  outline: 2px solid var(--accent-hi);
  outline-offset: 3px;
  border-bottom-color: var(--accent-hi);
}

.site-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(16, 44, 56, 0.9);
  border-bottom: 1px solid rgba(155, 226, 241, 0.14);
}

.site-header__inner,
.site-main,
.site-footer__inner {
  width: min(1040px, calc(100% - 2rem));
  margin: 0 auto;
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 0;
}

.site-header__profile {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid rgba(155, 226, 241, 0.35);
  background: #2e5d70;
  box-shadow: var(--shadow);
}

.site-header__copy {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.site-header__title {
  margin: 0;
  font-size: clamp(1.35rem, 2vw, 1.75rem);
  line-height: 1.15;
}

.site-header__tagline {
  margin: 0;
  color: var(--muted);
}

.site-main {
  flex: 1;
  padding: 2.5rem 0 3.5rem;
}

.hero {
  margin-bottom: 2rem;
  padding: 1.15rem 1.35rem;
  border: 1px solid rgba(155, 226, 241, 0.15);
  border-radius: calc(var(--radius) + 4px);
  background: linear-gradient(180deg, rgba(21, 58, 74, 0.95), rgba(12, 36, 47, 0.95));
  box-shadow: var(--shadow);
}

.hero__intro {
  margin: 0 0 0.35rem;
  color: var(--accent);
  font-size: 1.2rem;
  font-weight: 700;
}

.hero__headline {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.35;
  font-weight: 400;
  color: var(--accent);
}

.content-grid {
  display: grid;
  gap: 1.5rem;
}

.section-card {
  padding: 1.5rem;
  border-radius: var(--radius);
  background: rgba(21, 58, 74, 0.92);
  border: 1px solid rgba(155, 226, 241, 0.12);
  box-shadow: var(--shadow);
}

.section-card__title {
  margin: 0 0 1rem;
  font-size: 1.2rem;
  color: var(--accent);
}

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

.link-list li + li {
  margin-top: 0.7rem;
}

.gpt-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}

.gpt-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.7rem;
  min-height: 100%;
  padding: 1rem;
  text-align: center;
  background: linear-gradient(180deg, rgba(11, 37, 49, 0.92), rgba(16, 44, 56, 0.94));
  border: 1px solid rgba(155, 226, 241, 0.12);
  border-radius: 14px;
}

.gpt-card:hover {
  transform: translateY(-3px);
}

.gpt-card__image {
  width: 88px;
  height: 88px;
  object-fit: contain;
}

.gpt-card__name {
  color: var(--text);
}

.site-footer {
  border-top: 1px solid rgba(155, 226, 241, 0.14);
  background: rgba(16, 44, 56, 0.92);
}

.site-footer__inner {
  padding: 1rem 0 1.3rem;
  text-align: center;
  color: var(--muted);
}

@media (max-width: 640px) {
  .site-header__inner {
    align-items: flex-start;
  }

  .site-main {
    padding-top: 1.5rem;
  }

  .hero,
  .section-card {
    padding: 1.2rem;
  }
}