* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
  --bg: #ffffff;
  --text: #111111;
  --muted: #444444;
  --border: #dddddd;
  --accent: #111111;
  --surface: #f5f5f5;
  --max-width: 760px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
}

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

a:hover {
  text-decoration: none;
}

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

.header {
  border-bottom: 1px solid var(--accent);
  background: var(--bg);
}

.header-inner,
.content,
.footer-inner {
  width: min(100% - 32px, var(--max-width));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  object-fit: cover;
  flex-shrink: 0;
}

.brand h1 {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
}

.brand p {
  margin: 2px 0 0;
  font-size: 13px;
  color: var(--muted);
}

.lang-toggle {
  border: 1px solid var(--accent);
  background: var(--bg);
  color: var(--text);
  border-radius: 4px;
  padding: 8px 12px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.lang-toggle:hover {
  background: var(--surface);
}

.content {
  padding: 32px 0 48px;
  flex: 1;
}

.hero {
  margin-bottom: 28px;
}

.hero h2 {
  margin: 0 0 8px;
  font-size: 28px;
  line-height: 1.25;
}

.updated {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.intro {
  margin: 20px 0 0;
  font-size: 16px;
  color: var(--text);
}

.notice {
  margin-top: 24px;
  padding: 16px;
  border: 1px solid var(--accent);
  border-radius: 6px;
  background: var(--surface);
}

.notice strong {
  display: block;
  margin-bottom: 6px;
}

.policy-section {
  padding-top: 28px;
  border-top: 1px solid var(--border);
  margin-top: 28px;
}

.policy-section h3 {
  margin: 0 0 12px;
  font-size: 20px;
}

.policy-section p,
.policy-section li {
  font-size: 15px;
  color: var(--text);
}

.policy-section ul {
  margin: 12px 0 0;
  padding-left: 20px;
}

.policy-section li + li {
  margin-top: 8px;
}

.highlight-box {
  margin-top: 16px;
  padding: 16px;
  border-left: 4px solid var(--accent);
  background: var(--surface);
}

.highlight-box p {
  margin: 0;
}

.contact-card {
  margin-top: 16px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
}

.contact-card a {
  font-weight: 600;
  word-break: break-all;
}

.footer {
  border-top: 1px solid var(--accent);
  background: var(--surface);
}

.footer-inner {
  padding: 18px 0 24px;
  font-size: 13px;
  color: var(--muted);
}

.footer-inner p {
  margin: 0;
}

.back-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  width: 42px;
  height: 42px;
  border: 1px solid var(--accent);
  border-radius: 50%;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.back-top.visible {
  display: inline-flex;
}

.back-top svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero h2 {
    font-size: 24px;
  }
}