:root{--bg: #ffffff;--fg: #111827;--muted: #6b7280;--line: #e5e7eb;--accent: #1f2937;--ok: #047857}*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Hiragino Sans,Noto Sans JP,sans-serif;background:var(--bg);color:var(--fg);line-height:1.7;-webkit-text-size-adjust:100%}.app{max-width:640px;margin:0 auto;padding:16px 16px 96px}h1{font-size:20px;margin:8px 0 16px}h2{font-size:16px;margin:24px 0 8px}button{font:inherit;padding:14px 16px;border-radius:10px;border:1px solid var(--line);background:#fff;color:var(--fg);cursor:pointer;min-height:48px}button.primary{background:var(--accent);color:#fff;border-color:var(--accent);width:100%;font-weight:600}button:disabled{opacity:.45;cursor:default}textarea,input[type=text],input[type=password]{font:inherit;width:100%;padding:12px;border:1px solid var(--line);border-radius:10px;background:#fff;color:var(--fg)}textarea{min-height:96px;resize:vertical}.muted{color:var(--muted);font-size:14px}.stack>*+*{margin-top:12px}.card{border:1px solid var(--line);border-radius:12px;padding:12px}.nav{display:flex;gap:8px;margin-bottom:16px;flex-wrap:wrap}.nav button{flex:1;min-width:96px}.error{color:#b91c1c;font-size:14px;white-space:pre-line}.speak-row{display:flex;gap:8px;align-items:flex-start}.speak-row .en{flex:1;font-size:18px}button.speak{flex:none;min-width:96px;padding:12px 10px;font-size:14px}.tag{font-size:13px;border:1px solid var(--line);border-radius:999px;padding:1px 8px}button.word{padding:6px 4px;min-height:44px;border:none;background:none;color:inherit;font:inherit;border-bottom:2px dotted var(--muted);border-radius:4px;cursor:pointer}button.word:active{background:var(--line)}.heard-miss{text-decoration:line-through;text-decoration-thickness:2px;color:#b91c1c}