* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    /* 清爽渐变背景 */
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-container {
    background: #ffffff;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    width: 100%;
    max-width: 380px;
    padding: 40px 30px;
}

.login-header {
    text-align: center;
    margin-bottom: 35px;
}

.logo {
    font-size: 48px;
    margin-bottom: 15px;
}

.login-header h1 {
    color: #2c3e50;
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
}

.login-header p {
    color: #7f8c8d;
    font-size: 14px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    color: #2c3e50;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid #e0e6ed;
    border-radius: 8px;
    font-size: 16px;
    background: #f8f9fa;
    transition: all 0.3s ease;
    -webkit-tap-highlight-color: transparent;
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
    background: #ffffff;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

.form-group input::placeholder {
    color: #bdc3c7;
}

.error-msg {
    display: block;
    color: #e74c3c;
    font-size: 12px;
    margin-top: 6px;
    min-height: 16px;
}

.login-btn {
    width: 100%;
    padding: 16px;
    background: #3498db;
    color: #ffffff;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    -webkit-tap-highlight-color: transparent;
    margin-top: 10px;
}

.login-btn:hover {
    background: #2980b9;
}

.login-btn:active {
    transform: scale(0.98);
}

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

.login-btn.loading {
    position: relative;
    color: transparent;
}

.login-btn.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid #ffffff;
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    top: 50%;
    left: 50%;
    margin-left: -10px;
    margin-top: -10px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.login-footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid #ecf0f1;
}

.login-footer p {
    color: #bdc3c7;
    font-size: 12px;
}

/* 移动端适配 */
@media screen and (max-width: 480px) {
    .login-container {
        padding: 30px 20px;
    }
    
    .login-header h1 {
        font-size: 22px;
    }
    
    .logo {
        font-size: 42px;
    }
    
    .form-group input {
        font-size: 16px;
        padding: 12px 14px;
    }
    
    .login-btn {
        padding: 14px;
        font-size: 16px;
    }
}