* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", sans-serif;
}

/* 主体：渐变流体背景 */
body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    background-size: 400% 400%;
    animation: gradientBG 15s ease infinite;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

/* iOS 液态玻璃卡片 */
.glass-card {
    width: 90%;
    max-width: 420px;
    padding: 42px 34px;
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border: 1px solid rgba(255, 255, 255, 0.28);
    border-radius: 26px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.glass-card h2 {
    color: #ffffff;
    text-align: center;
    margin-bottom: 32px;
    font-weight: 500;
}

.form-item {
    margin-bottom: 20px;
}

.form-item label {
    display: block;
    color: rgba(255,255,255,0.92);
    margin-bottom:8px;
    font-size:14px;
}

.form-item input {
    width:100%;
    padding:14px 16px;
    border: 1px solid rgba(255,255,255,0.24);
    border-radius:14px;
    outline:none;
    background: rgba(255,255,255,0.08);
    backdrop-filter: blur(10px) saturate(150%);
    -webkit-backdrop-filter: blur(10px) saturate(150%);
    color:#fff;
    font-size:15px;
    transition:0.3s ease;
}
.form-item input::placeholder {
    color:rgba(255,255,255,0.52);
}
.form-item input:focus {
    border-color:rgba(255,255,255,0.6);
    background: rgba(255,255,255,0.18);
}

.error-tip {
    margin-top:6px;
    font-size:13px;
    color:#ffd2d2;
}

/* 消息提示 */
.message {
    text-align: center;
    margin-bottom: 15px;
    padding: 10px;
    border-radius: 10px;
    font-size: 14px;
    display: none;
}
.message.success {
    background: rgba(76, 175, 80, 0.3);
    color: #fff;
    display: block;
}
.message.error {
    background: rgba(244, 67, 54, 0.3);
    color: #fff;
    display: block;
}

/* 注册按钮，PC悬浮流光特效 */
.register-btn {
    position:relative;
    overflow:hidden;
    width:100%;
    padding:14px;
    margin-top:8px;
    border:none;
    border-radius:14px;
    background:rgba(255,255,255,0.16);
    backdrop-filter: blur(14px) saturate(170%);
    -webkit-backdrop-filter: blur(14px) saturate(170%);
    border:1px solid rgba(255,255,255,0.32);
    color:#fff;
    font-size:16px;
    cursor:pointer;
    transition: 0.3s ease;
}

.register-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* 仅电脑端启用hover流光动画 */
@media (min-width:768px) {
    .register-btn::before {
        content:"";
        position:absolute;
        top:0;
        left:-100%;
        width:100%;
        height:100%;
        background: linear-gradient(90deg, transparent, rgba(255,255,255,0.35), transparent);
        transition: left 0.6s ease;
    }
    .register-btn:hover::before {
        left:100%;
    }
    .register-btn:hover {
        background:rgba(255,255,255,0.28);
        transform: translateY(-2px);
    }
}

.tip {
    text-align:center;
    margin-top:24px;
    color:rgba(255,255,255,0.85);
    font-size:14px;
}
.tip a {
    color:#fff;
    text-decoration:none;
}