/* [P4.1][FE] Trang đăng nhập / 2FA — CSS riêng, không build step */
*{box-sizing:border-box}
:root{--bg:#f3f4f6;--card:#fff;--text:#111827;--muted:#6b7280;--line:#d1d5db;--brand:#2563eb;--err-bg:#fee2e2;--err:#b91c1c}
@media(prefers-color-scheme:dark){:root{--bg:#0b1220;--card:#111827;--text:#f3f4f6;--muted:#9ca3af;--line:#374151;--brand:#3b82f6;--err-bg:#450a0a;--err:#fecaca}}
body.auth{margin:0;min-height:100vh;display:flex;align-items:center;justify-content:center;padding:16px;background:var(--bg);color:var(--text);font:15px/1.5 system-ui,sans-serif}
.auth-card{width:100%;max-width:400px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:28px 24px;box-shadow:0 10px 30px rgba(0,0,0,.08)}
.auth-brand{display:flex;align-items:center;gap:10px;font-weight:700;margin-bottom:20px}
.auth-logo{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border-radius:9px;background:var(--brand);color:#fff}
.auth-card h1{font-size:22px;margin:0}
.auth-sub{color:var(--muted);margin:4px 0 18px}
.auth-field{margin-bottom:14px}
.auth-field label{display:block;font-weight:600;margin-bottom:4px}
.auth-card input[type=email],.auth-card input[type=password],.auth-card input[type=text]{width:100%;padding:11px 12px;border:1px solid var(--line);border-radius:8px;background:transparent;color:var(--text);font:inherit}
.auth-card input:focus{outline:2px solid var(--brand);outline-offset:1px;border-color:transparent}
.auth-pw{position:relative}.auth-pw input{padding-right:64px}
.auth-pw button{position:absolute;right:6px;top:50%;transform:translateY(-50%);border:0;background:none;color:var(--brand);font:inherit;font-size:13px;cursor:pointer;padding:6px 8px}
.auth-check{display:flex;gap:8px;align-items:center;margin:4px 0 18px;color:var(--muted)}
.auth-btn{width:100%;padding:12px;border:0;border-radius:8px;background:var(--brand);color:#fff;font:inherit;font-weight:600;cursor:pointer}
.auth-btn:hover{filter:brightness(1.08)}
.auth-alert{background:var(--err-bg);color:var(--err);padding:10px 12px;border-radius:8px;margin-bottom:14px;font-size:14px}
.auth-code{font-size:22px;letter-spacing:.18em;text-align:center}
.auth-foot{text-align:center;margin:16px 0 0}.auth-foot a{color:var(--brand);text-decoration:none}