:root{--ink:#121814;--paper:#f6f7f4;--card:#fff;--line:#d7ddd6;--go:#1f4a34}
*{box-sizing:border-box}body{margin:0;font-family:ui-sans-serif,system-ui,sans-serif;background:var(--paper);color:var(--ink)}
.stamp{margin:0;padding:12px 24px;background:#111;color:#fff;font-size:18px;letter-spacing:.01em;border-bottom:4px solid #c8f54a}
.stamp strong{font-weight:800}
header{display:flex;justify-content:space-between;align-items:center;padding:16px 24px;border-bottom:1px solid var(--line);background:var(--card)}
.brand{display:flex;gap:8px;align-items:center;text-decoration:none;color:inherit;font-weight:800}
.brand span{background:var(--go);color:#fff;padding:8px 10px;border-radius:10px}
.brand small{display:block;font-size:10px;letter-spacing:.12em;color:#667066}
.meta{font-size:12px;color:#667066}
main{max-width:1180px;margin:0 auto;padding:28px 20px}
.intro h1{font-size:clamp(28px,4vw,44px);letter-spacing:-.04em;line-height:1.1;margin:8px 0 12px}
.intro p{color:#4d5a50;max-width:720px;line-height:1.5}
.eyebrow{font-size:11px;letter-spacing:.14em;font-weight:800;color:#5b7462}
.why{margin:20px 0;padding:14px 16px;border:1px solid #e3d7b4;background:#fff9e8;border-radius:12px;display:grid;gap:4px}
.workspace{display:grid;grid-template-columns:240px 1fr;gap:20px}
nav{display:flex;flex-direction:column;gap:6px}
nav button{text-align:left;border:1px solid transparent;background:transparent;padding:10px 12px;border-radius:10px;cursor:pointer}
nav button b{display:block;font-size:11px;color:#667066}
nav button.on{background:#fff;border-color:var(--line)}
.editor{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px}
.modes{display:flex;gap:6px;margin:12px 0}
.modes button,.bar button{border:1px solid var(--line);background:#f4f6f1;border-radius:8px;padding:8px 12px;cursor:pointer}
.modes .on,.primary{background:var(--go);color:#fff;border-color:var(--go)}
.bar{display:flex;gap:10px;align-items:center;margin-bottom:8px}
textarea{width:100%;min-height:420px;font:12px/1.6 ui-monospace,monospace;padding:14px;border:1px solid var(--line);border-radius:10px;background:#f7f9f5}
@media(max-width:800px){.workspace{grid-template-columns:1fr}}