:root {
  --bg-1: #06070d;
  --bg-2: #0a0d14;
  --bg-3: #12182a;
  --line: rgba(255, 255, 255, 0.12);
  --line-strong: rgba(255, 255, 255, 0.2);
  --text: #f5f6fb;
  --muted: #a4acc3;
  --cool: #69dcff;
  --warm: #ffd26d;
  --shadow: 0 28px 80px rgba(0, 0, 0, 0.42);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--text);
  background:
    radial-gradient(circle at 20% 20%, rgba(105, 220, 255, 0.13), transparent 24%),
    radial-gradient(circle at 82% 18%, rgba(255, 210, 109, 0.12), transparent 22%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 44%, #080b12 100%);
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
}

.portal-body::before,
.portal-body::after {
  content: "";
  position: fixed;
  inset: auto;
  pointer-events: none;
  filter: blur(70px);
  opacity: 0.44;
}

.portal-body::before {
  top: 90px;
  left: -110px;
  width: 300px;
  height: 300px;
  background: rgba(105, 220, 255, 0.14);
}

.portal-body::after {
  right: -100px;
  bottom: 40px;
  width: 340px;
  height: 340px;
  background: rgba(255, 210, 109, 0.11);
}

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

h1,
p {
  margin-top: 0;
}

.portal-shell,
.detail-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.portal-stage,
.detail-panel {
  width: min(100%, 820px);
  border: 1px solid var(--line);
  border-radius: 34px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.025));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), var(--shadow);
  backdrop-filter: blur(18px);
}

.portal-stage {
  padding: 56px 28px;
  text-align: center;
}

.portal-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.04);
  color: #dce9f5;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.portal-stage h1,
.detail-panel h1 {
  margin-bottom: 0;
  font-size: clamp(3rem, 8vw, 5.6rem);
  line-height: 0.95;
  letter-spacing: -0.06em;
}

.portal-tabs {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 28px;
}

.portal-tab {
  min-width: 210px;
  padding: 17px 22px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.09), rgba(255, 255, 255, 0.03));
  color: var(--text);
  font-weight: 600;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.portal-tab:hover,
.portal-tab:focus-visible,
.subpage-nav a:hover,
.subpage-nav a:focus-visible {
  transform: translateY(-2px);
  border-color: var(--line-strong);
  background: linear-gradient(135deg, rgba(105, 220, 255, 0.13), rgba(255, 255, 255, 0.04));
}

.portal-tab--secondary {
  color: var(--muted);
}

.portal-body--detail {
  display: block;
}

.subpage-bar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  width: min(calc(100% - 32px), 1100px);
  margin: 18px auto 0;
  padding: 14px 18px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.03));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), var(--shadow);
  backdrop-filter: blur(18px);
}

.subpage-brand {
  font-weight: 700;
  letter-spacing: -0.03em;
}

.subpage-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.subpage-nav a {
  padding: 10px 14px;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--muted);
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.subpage-nav a.is-active {
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
}

.detail-panel {
  padding: 42px 28px;
}

.detail-copy {
  max-width: 660px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.06rem;
}

.portal-tabs--detail {
  justify-content: flex-start;
}

@media (max-width: 700px) {
  .portal-stage,
  .detail-panel {
    padding: 34px 20px;
  }

  .subpage-bar {
    flex-direction: column;
    align-items: flex-start;
  }

  .portal-tab {
    width: 100%;
    min-width: 0;
    text-align: center;
  }

  .portal-tabs--detail {
    justify-content: stretch;
  }
}