/* ===== 基础重置 ===== */
* {
    box-sizing: border-box;
    font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
}

body {
    background: linear-gradient(145deg, #f6f9fc 0%, #e9f0f5 100%);
    min-height: 100vh;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1.5rem;
}

.card {
    background: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 48px;
    box-shadow: 0 25px 45px -12px rgba(0, 20, 30, 0.35);
    padding: 2.5rem 2.2rem;
    max-width: 580px;
    width: 100%;
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.back-link {
    font-size: 0.85rem;
    color: #4c6f83;
    text-decoration: none;
    padding: 0.3rem 1rem;
    border-radius: 30px;
    background: #e8edf2;
    transition: 0.15s ease;
}
.back-link:hover { background: #d5dde5; }

@media (max-width: 550px) {
    .card { padding: 1.8rem 1.2rem; border-radius: 32px; }
}