:root { --bg: #f5f7fb; --surface: #ffffff; --border: #e0e4ee; --accent: #2563eb; --accent-soft: #dbeafe; --text-main: #111827; --text-muted: #6b7280; }
* { box-sizing: border-box; }
body { margin: 0; font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; background: var(--bg); color: var(--text-main); min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 1.5rem; }
.login-box { background: var(--surface); border-radius: 0.75rem; box-shadow: 0 4px 20px rgba(15, 23, 42, 0.12); border: 1px solid var(--border); padding: 2rem; width: 100%; max-width: 400px; }
.login-box h1 { margin: 0 0 1.5rem; font-size: 1.35rem; font-weight: 600; text-align: center; }
.login-box .form-group { margin-bottom: 1.25rem; }
.login-box label { display: block; font-weight: 600; font-size: 0.9rem; margin-bottom: 0.4rem; color: var(--text-main); }
.login-box input { width: 100%; padding: 0.6rem 0.85rem; border: 1px solid var(--border); border-radius: 0.5rem; font-size: 1rem; box-sizing: border-box; }
.login-box input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.login-box .error { background: #fef2f2; color: #b91c1c; padding: 0.5rem 0.75rem; border-radius: 0.5rem; font-size: 0.9rem; margin-bottom: 1rem; }
.login-box .btn { width: 100%; padding: 0.75rem 1rem; background: var(--accent); color: #fff; border: none; border-radius: 0.5rem; font-size: 1rem; font-weight: 600; cursor: pointer; }
.login-box .btn:hover { background: #1d4ed8; }
.login-box .brand { text-align: center; margin-bottom: 1.5rem; }
.login-box .brand img { height: 36px; width: auto; }
.login-box .footer-link { text-align: center; margin-top: 1rem; font-size: 0.9rem; }
.login-box .footer-link a { color: var(--accent); text-decoration: none; }
.login-box .footer-link a:hover { text-decoration: underline; }
@media (max-width: 768px) {
    body { padding: 1rem 0.75rem; }
    .login-box { padding: 1.5rem 1.25rem; max-width: 100%; }
    .login-box input { font-size: 16px; min-height: 44px; }
    .login-box .btn { min-height: 48px; font-size: 1rem; }
}