/* login.html 用（CSP によりインラインスタイルは使わない） */
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 16px; background: #f4f6f9; color: #1c2430;
  font-family: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", system-ui, sans-serif; }
main { width: 100%; max-width: 400px; background: #fff; border: 1px solid #e2e8f0; border-radius: 18px; padding: 28px 24px; box-shadow: 0 8px 30px rgb(32 40 53 / 6%); }
h1 { margin: 0 0 4px; font-size: 20px; }
p { margin: 0 0 20px; font-size: 13px; line-height: 1.7; color: #64748b; }
a.btn, button { display: block; width: 100%; padding: 12px; border-radius: 12px; font-size: 15px; font-weight: 700; text-align: center; text-decoration: none; cursor: pointer; }
a.btn { background: #2563eb; color: #fff; border: 0; }
button { margin-top: 10px; background: #fff; color: #475569; border: 1px dashed #94a3b8; font-size: 13px; }
.error { display: none; margin-bottom: 16px; padding: 10px 12px; border-radius: 10px; background: #fff1f2; color: #9f1239; font-size: 13px; }
.dev { display: none; }