:root {
  color-scheme: dark;
  --bg: #07111f;
  --surface: #111f34;
  --text: #f7fbff;
  --muted: #a7b8ca;
  --line: #2b3a48;
  --brand: #2563eb;
  --brand-2: #0f9f9a;
  --danger-bg: #291612;
  --danger-line: #8f4938;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1117;
    --surface: #151d25;
    --text: #f7fbff;
    --muted: #a7b8ca;
    --line: #2b3a48;
    --danger-bg: #291612;
    --danger-line: #8f4938;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  overflow-x: hidden;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px clamp(16px, 6vw, 84px);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--brand);
  font-size: 22px;
  font-weight: 800;
  text-decoration: none;
}

.brand span {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 10px;
  background: linear-gradient(135deg, #1477e9, #20b7c7);
  color: #fff;
}

nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

nav a, .button {
  color: inherit;
  font-weight: 700;
  text-decoration: none;
}

select {
  min-width: 120px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
}

.about-shell {
  width: min(1120px, calc(100vw - 32px));
  margin: 0 auto;
  padding: 44px 0 72px;
}

.hero {
  padding: clamp(28px, 6vw, 68px);
  border-radius: 18px;
  background:
    radial-gradient(circle at 82% 18%, color-mix(in srgb, var(--brand-2) 24%, transparent), transparent 30%),
    linear-gradient(135deg, color-mix(in srgb, var(--brand) 18%, var(--surface)), var(--surface));
  border: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--brand);
  font-weight: 800;
}

h1, h2, p { overflow-wrap: anywhere; }
h1 {
  max-width: 850px;
  margin: 0;
  font-size: clamp(34px, 6vw, 68px);
  line-height: 1.03;
  letter-spacing: 0;
}

.hero p:not(.eyebrow) {
  max-width: 760px;
  color: var(--muted);
  font-size: 19px;
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 11px 18px;
  border-radius: 8px;
  border: 1px solid var(--line);
}

.button.primary {
  background: var(--brand);
  color: #fff;
  border-color: var(--brand);
}

.section {
  margin-top: 28px;
  padding: clamp(22px, 4vw, 36px);
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
}

.text-stack {
  display: grid;
  gap: 14px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.65;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.feature-card {
  min-height: 150px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: color-mix(in srgb, var(--surface) 88%, var(--brand) 12%);
}

.feature-card strong {
  display: block;
  margin-bottom: 9px;
  font-size: 18px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.5;
}

.disclaimer {
  margin-top: 28px;
  padding: clamp(22px, 4vw, 32px);
  border: 1px solid var(--danger-line);
  border-radius: 14px;
  background: var(--danger-bg);
}

.meta-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.meta-grid a, .meta-grid span, .meta-button {
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  text-decoration: none;
  background: var(--surface);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.support-dialog {
  width: min(520px, calc(100vw - 28px));
  border: 0;
  border-radius: 14px;
  padding: 26px;
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 30px 90px rgba(2, 6, 23, .34);
}

.support-dialog::backdrop {
  background: rgba(2, 6, 23, .58);
  backdrop-filter: blur(4px);
}

.support-dialog h2 {
  margin: 0 42px 18px 0;
}

.support-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  font-size: 24px;
  cursor: pointer;
}

.support-form {
  display: grid;
  gap: 14px;
}

.support-form label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-weight: 700;
}

.support-form input, .support-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 11px 12px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}

.support-status {
  min-height: 22px;
  margin: 0;
  color: var(--muted);
}

[dir="rtl"] .topbar, [dir="rtl"] .hero, [dir="rtl"] .section, [dir="rtl"] .disclaimer { text-align: right; }

@media (max-width: 820px) {
  .topbar { align-items: flex-start; flex-direction: column; }
  .feature-grid, .meta-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .button { width: 100%; }
}