:root { --bg:#ffffff; --fg:#131313; --muted:#666; --border:#e8e8e8; --accent:#006E54; }
@media (prefers-color-scheme: dark) {
  :root { --bg:#0b0c0f; --fg:#f2f2f2; --muted:#9aa4b2; --border:#1e222a; --accent:#21C07A; }
}
html { scroll-behavior:smooth; }
html, body { margin:0; padding:0; background:var(--bg); color:var(--fg); font:16px/1.75 system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji"; }
.container { max-width: 820px; margin: clamp(24px,4vw,48px) auto; padding: 0 16px 40px; }

/* Header & Nav */
header h1 { margin: 0 0 4px; font-size: clamp(28px, 5vw, 40px); letter-spacing: 0.2px; }
.lang { float:right; font-size:14px; }
header:after { content:""; display:block; clear:both; }

.topnav { display:flex; flex-wrap:wrap; gap:14px; margin: 10px 0 24px; }
.topnav a { color: var(--muted); text-decoration:none; border:1px solid var(--border); padding:4px 10px; border-radius:999px; font-size:14px; }
.topnav a:hover { color: var(--fg); border-color: var(--fg); }

.name-ja { white-space: nowrap; letter-spacing: 0; }
.name-en { letter-spacing: 0.2px; } /* 既存の微調整は英字側だけに */
@media (max-width: 480px) {
  header h1 { font-size: clamp(22px, 6vw, 34px); }
}

/* Typography */
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h2 { margin-top: 34px; font-size: 20px; padding-bottom: 6px; position: relative; }
h2:after { content:""; position:absolute; left:0; bottom:0; width: 84px; height: 2px; background: linear-gradient(90deg, var(--accent), transparent); opacity:0.5; }
h3 { margin: 18px 0 10px; font-size: 16px; color: var(--muted); }
.meta { color: var(--muted); font-size: 14px; }
.footer { margin-top: 40px; color: var(--muted); font-size: 14px; }

/* Lists & Cards */
ul, ol { padding-left: 1.1rem; }
.list-clean { list-style: none; padding-left:0; }
.paper { padding: 6px 0 6px 12px; border-left: 3px solid var(--border); margin: 8px 0; }
.talk { margin: 6px 0; }

/* Small helper */
.pill { display:inline-block; padding:2px 8px; border:1px solid var(--border); border-radius:999px; font-size:12px; color:var(--muted); margin-left:8px; }