:root {
  --red: #ff4438;
  --blue: #2f6bff;
  --green: #15b36b;
  --yellow: #fec01d;
  --ink: #1e1e1e;
  --text: #1e1e1e;
  --muted: #5d6270;
  --bg: #ffffff;
  --panel: #f4f6fa;
  --line: #e3e6ed;
  --link: #2257d6;
}

@media (prefers-color-scheme: dark) {
  :root {
    --text: #eceef3;
    --muted: #a3a9b6;
    --bg: #121317;
    --panel: #1c1e24;
    --line: #2c2f38;
    --link: #8aaeff;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }

header.top { padding: 28px 0 8px; }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--text); text-decoration: none; font-weight: 700; font-size: 20px; letter-spacing: -0.01em; }
.brand img { width: 40px; height: auto; display: block; }

main { padding: 8px 0 48px; }

h1 { font-size: 34px; line-height: 1.15; letter-spacing: -0.02em; margin: 24px 0 8px; }
h2 { font-size: 22px; line-height: 1.3; margin: 36px 0 8px; }
h3 { font-size: 18px; margin: 24px 0 4px; }
p, ul { margin: 0 0 14px; }
ul { padding-left: 22px; }
li { margin: 4px 0; }
a { color: var(--link); text-underline-offset: 2px; }

.updated { color: var(--muted); font-size: 15px; margin-bottom: 20px; }

.lang-switch { display: flex; gap: 8px; margin: 4px 0 8px; font-size: 15px; }
.lang-switch a { padding: 4px 12px; border: 1px solid var(--line); border-radius: 999px; text-decoration: none; color: var(--text); }

.summary { background: var(--panel); border-radius: 16px; padding: 18px 20px; margin: 20px 0 8px; }
.summary p:last-child, .summary ul:last-child { margin-bottom: 0; }

.contact { background: var(--panel); border-radius: 16px; padding: 18px 20px; margin: 20px 0; }
.contact .email { font-size: 22px; font-weight: 700; }
.contact p:last-child { margin-bottom: 0; }

section.lang + section.lang { border-top: 1px solid var(--line); margin-top: 48px; padding-top: 8px; }

.hero { text-align: center; padding: 40px 0 16px; }
.hero .logo { width: 132px; height: auto; margin: 0 auto 20px; display: block; }
.hero h1 { font-size: 44px; margin: 0 0 12px; }
.hero .tagline { font-size: 21px; line-height: 1.45; max-width: 560px; margin: 0 auto 10px; }
.hero .tagline-en { color: var(--muted); font-size: 17px; max-width: 520px; margin: 0 auto 24px; }
.soon { display: inline-block; background: var(--ink); color: #fff; border-radius: 999px; padding: 10px 20px; font-weight: 600; font-size: 16px; }
@media (prefers-color-scheme: dark) { .soon { background: #fff; color: var(--ink); } }

.features { display: grid; gap: 12px; margin: 40px 0 8px; }
.feature { background: var(--panel); border-radius: 16px; padding: 16px 20px; border-left: 6px solid var(--c, var(--blue)); }
.feature.red { --c: var(--red); }
.feature.blue { --c: var(--blue); }
.feature.green { --c: var(--green); }
.feature h3 { margin: 0 0 4px; }
.feature p { margin: 0; color: var(--muted); }

footer.bottom { border-top: 1px solid var(--line); padding: 20px 0 40px; color: var(--muted); font-size: 15px; }
footer.bottom nav { display: flex; flex-wrap: wrap; gap: 6px 18px; margin-bottom: 6px; }
footer.bottom a { color: var(--muted); }

@media (max-width: 480px) {
  body { font-size: 16px; }
  h1 { font-size: 28px; }
  .hero h1 { font-size: 36px; }
  .hero .tagline { font-size: 19px; }
}

code { font: 0.88em ui-monospace, SFMono-Regular, Menlo, monospace; background: var(--panel); padding: 1px 5px; border-radius: 5px; }