:root {
  --bg: #0b0b0f;
  --bg-grad-mid: #14101f;
  --bg-elevated: #131419;
  --text: #f2f2f7;
  --text-secondary: #9ca3af;
  --text-tertiary: #6b7280;
  --accent: #0a84ff;
  --purple: #7c5cff;
  --border: rgba(255, 255, 255, 0.08);
  --header-bg: rgba(19, 20, 25, 0.6);
  --footer-border: rgba(255, 255, 255, 0.06);
  --chip-bg: rgba(124, 92, 255, 0.14);
  --chip-text: #c4b5fd;
  --card-shadow: none;
  --brand-mark-shadow: 0 0 24px rgba(124, 92, 255, 0.35);
  --max-width: 720px;
}

[data-theme="light"],
:root.theme-light {
  --bg: #f4f6fa;
  --bg-grad-mid: #eef2f7;
  --bg-elevated: #ffffff;
  --text: #14161a;
  --text-secondary: #5a606b;
  --text-tertiary: #848b97;
  --accent: #0a63d6;
  --purple: #6350b0;
  --border: rgba(15, 23, 41, 0.08);
  --header-bg: rgba(255, 255, 255, 0.85);
  --footer-border: rgba(15, 23, 41, 0.06);
  --chip-bg: rgba(99, 80, 176, 0.1);
  --chip-text: #5b3fc8;
  --card-shadow: 0 2px 12px rgba(15, 23, 41, 0.05);
  --brand-mark-shadow: 0 4px 16px rgba(99, 80, 176, 0.25);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f4f6fa;
    --bg-grad-mid: #eef2f7;
    --bg-elevated: #ffffff;
    --text: #14161a;
    --text-secondary: #5a606b;
    --text-tertiary: #848b97;
    --accent: #0a63d6;
    --purple: #6350b0;
    --border: rgba(15, 23, 41, 0.08);
    --header-bg: rgba(255, 255, 255, 0.85);
    --footer-border: rgba(15, 23, 41, 0.06);
    --chip-bg: rgba(99, 80, 176, 0.1);
    --chip-text: #5b3fc8;
    --card-shadow: 0 2px 12px rgba(15, 23, 41, 0.05);
    --brand-mark-shadow: 0 4px 16px rgba(99, 80, 176, 0.25);
  }
}

[data-theme="dark"],
:root.theme-dark {
  --bg: #0b0b0f;
  --bg-grad-mid: #14101f;
  --bg-elevated: #131419;
  --text: #f2f2f7;
  --text-secondary: #9ca3af;
  --text-tertiary: #6b7280;
  --accent: #0a84ff;
  --purple: #7c5cff;
  --border: rgba(255, 255, 255, 0.08);
  --header-bg: rgba(19, 20, 25, 0.6);
  --footer-border: rgba(255, 255, 255, 0.06);
  --chip-bg: rgba(124, 92, 255, 0.14);
  --chip-text: #c4b5fd;
  --card-shadow: none;
  --brand-mark-shadow: 0 0 24px rgba(124, 92, 255, 0.35);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue", sans-serif;
  background: linear-gradient(160deg, var(--bg) 0%, var(--bg-grad-mid) 50%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
}

header {
  padding: 48px 24px 24px;
  text-align: center;
  border-bottom: 1px solid var(--border);
  background: var(--header-bg);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}

.brand-mark {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--purple), var(--accent));
  box-shadow: var(--brand-mark-shadow);
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.tagline {
  color: var(--text-tertiary);
  font-size: 14px;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 32px 24px 64px;
}

h1 {
  font-size: 28px;
  margin: 0 0 8px;
}

.updated {
  color: var(--text-tertiary);
  font-size: 13px;
  margin-bottom: 32px;
}

h2 {
  font-size: 18px;
  margin: 28px 0 10px;
  color: var(--text);
}

p {
  margin: 0 0 14px;
  color: var(--text-secondary);
  white-space: pre-line;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

footer {
  text-align: center;
  padding: 24px;
  color: var(--text-tertiary);
  font-size: 13px;
  border-top: 1px solid var(--footer-border);
}

.nav-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.support-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  margin: 16px 0;
  box-shadow: var(--card-shadow);
}

.support-card h2 {
  margin-top: 0;
}