:root{--primary:#4f46e5;--primary-light:#6366f1;--success:#10b981;--danger:#ef4444;--warning:#f59e0b;--bg-color:#f8fafc;--text-color:#1e293b;--text-light:#64748b;--radius:12px}
*{margin:0;padding:0;box-sizing:border-box;font-family:'PingFang SC','Microsoft YaHei',Inter,sans-serif}
body,html{overflow:hidden;height:100%}
body{background:linear-gradient(180deg,#f8fafc 0%,#eef2ff 100%);color:var(--text-color);line-height:1.6;padding:20px}
.container{max-width:560px;margin:0 auto;padding:20px;height:100%;display:flex;flex-direction:column;justify-content:center}
header{text-align:center;margin-bottom:32px}
.title{font-size:2.1rem;font-weight:700;color:var(--primary);margin-bottom:10px}
.tagline{font-size:1rem;color:var(--text-light)}
.form-group{margin-bottom:18px}
label{display:block;margin-bottom:8px;font-weight:500}
.form-control{width:100%;height:50px;padding:0 16px;border:1px solid #c7d2fe;border-radius:var(--radius);font-size:1rem;transition:all .2s ease;background:#fff}
.form-control:focus{border-color:var(--primary);outline:0;box-shadow:0 0 0 4px rgba(79,70,229,.12)}
.btn{width:100%;height:52px;background:var(--primary);color:#fff;border:none;border-radius:var(--radius);cursor:pointer;font-size:1rem;font-weight:600;display:inline-flex;align-items:center;justify-content:center;gap:10px;transition:all .2s ease;margin:16px 0 24px}
.btn:hover{background:var(--primary-light)}
.alert{padding:16px;border-radius:var(--radius);font-size:.95rem;margin-bottom:20px;display:flex;align-items:center;gap:10px;animation:fadeIn .4s ease-out}
.alert-success{background:rgba(16,185,129,.1);border:1px solid var(--success);color:var(--success)}
.alert-danger{background:rgba(239,68,68,.08);border:1px solid var(--danger);color:var(--danger)}
@keyframes fadeIn{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}
@media (max-width:480px){.title{font-size:1.6rem}.container{padding:12px}}
.form-group .example-text{color:#94a3b8;font-size:.85em;margin-left:5px}