/* ===== 认证页面 (注册/登录) ===== */
.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    position: relative;
}

.auth-bg {
    position: fixed;
    inset: 0;
    pointer-events: none;
}
.auth-gradient {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse 60% 50% at 50% 0%, rgba(59, 130, 246, 0.12) 0%, transparent 50%),
                radial-gradient(ellipse 40% 30% at 80% 100%, rgba(245, 158, 11, 0.06) 0%, transparent 50%);
}
.auth-grid {
    position: absolute;
    inset: 0;
    background-image: linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
    background-size: 40px 40px;
}

.auth-back {
    position: fixed;
    top: 1.5rem;
    left: 1.5rem;
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s;
    z-index: 10;
}
.auth-back:hover { color: var(--color-primary); }

.auth-container {
    position: relative;
    width: 100%;
    max-width: 480px;
}

.auth-card {
    background: rgba(26, 34, 52, 0.9);
    border: 1px solid var(--color-border);
    border-radius: 20px;
    padding: 2.5rem;
    backdrop-filter: blur(20px);
    animation: authCardIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
@keyframes authCardIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.auth-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 0.25rem;
}
.auth-subtitle {
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.95rem;
    margin-bottom: 2rem;
}

.auth-form .form-group {
    margin-bottom: 1.25rem;
}
.auth-form .form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
.auth-form label {
    display: block;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 0.5rem;
}
.auth-form input,
.auth-form textarea {
    width: 100%;
    padding: 0.85rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    color: var(--color-text);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: border-color 0.3s;
}
.auth-form input::placeholder,
.auth-form textarea::placeholder {
    color: var(--color-text-muted);
    opacity: 0.6;
}
.auth-form input:focus,
.auth-form textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

.auth-form .btn-block {
    width: 100%;
    margin-top: 0.5rem;
    padding: 1rem;
}

.auth-switch {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--color-text-muted);
    font-size: 0.9rem;
}
.auth-switch a {
    color: var(--color-primary);
    text-decoration: none;
}
.auth-switch a:hover { text-decoration: underline; }

@media (max-width: 520px) {
    .auth-form .form-row {
        grid-template-columns: 1fr;
    }
}