:root {
  --bg-start: #142446;
  --bg-mid: #05070f;
  --bg-end: #020308;
  --grid-h: rgba(88, 132, 220, 0.08);
  --grid-v: rgba(88, 132, 220, 0.06);
  --panel: rgba(12, 21, 40, 0.92);
  --border: rgba(141, 170, 223, 0.28);
  --text: #eaf2ff;
  --muted: #9db1cf;
  --link: #9fc6ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Space Grotesk', 'Segoe UI', sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 20% 15%, var(--bg-start) 0%, var(--bg-mid) 44%, var(--bg-end) 100%);
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image: linear-gradient(var(--grid-h) 1px, transparent 1px), linear-gradient(90deg, var(--grid-v) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: radial-gradient(circle at center, #000 40%, transparent 100%);
}

.topbar {
  display: grid;
  gap: 0;
  padding: 0.3rem 0.65rem;
  border-bottom: 1px solid rgba(167, 198, 245, 0.15);
  background: rgba(4, 9, 18, 0.7);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  min-width: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.48rem;
  min-width: 0;
  text-decoration: none;
  color: inherit;
}

.brand-mark {
  width: 24px;
  height: 24px;
  border-radius: 5px;
  background: url('/favicon.svg') center / cover no-repeat;
  box-shadow: 0 0 10px rgba(0, 229, 255, 0.5);
}

.brand h1 {
  margin: 0;
  font-family: 'Space Grotesk', 'Segoe UI', sans-serif;
  font-weight: 700;
  font-size: 1.03rem;
  line-height: 1.48;
  letter-spacing: 0.04em;
  padding-bottom: 0.2em;
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.16rem;
  border: 1px solid rgba(148, 176, 223, 0.34);
  border-radius: 999px;
  background: rgba(9, 17, 34, 0.7);
  padding: 0.12rem;
}

.lang-btn {
  border: 0;
  background: transparent;
  color: #9eb0cd;
  border-radius: 999px;
  padding: 0.2rem 0.45rem;
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
}

.lang-btn.active {
  background: rgba(84, 142, 255, 0.35);
  color: #eaf2ff;
}

.wrap {
  width: min(940px, 94vw);
  margin: 0 auto;
  padding: 1rem 0 2rem;
}

.back {
  display: inline-block;
  margin-bottom: 0.8rem;
  color: var(--link);
  text-decoration: none;
  font-weight: 600;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1rem;
}

h1,
h2 {
  font-family: 'Syne', sans-serif;
  margin: 0 0 0.6rem;
}

h1 {
  font-size: 1.6rem;
}

h2 {
  font-size: 1.05rem;
  margin-top: 1.2rem;
}

p {
  margin: 0.35rem 0;
  color: #d7e5ff;
  line-height: 1.6;
}

a {
  color: var(--link);
}

.muted {
  color: var(--muted);
}

@media (max-width: 700px) {
  .topbar {
    padding: 0.35rem 0.55rem 0.45rem;
  }

  .brand h1 {
    font-size: 1rem;
  }
}