/* 登录页面样式 */
* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.gradient-wrapper {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    padding-top: 30px;
}

.login-box {
    max-width: 500px;
    width: 100%;
    margin-left: auto;
    margin-right: auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 15px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1), 0 5px 15px rgba(0, 0, 0, 0.07);
    backdrop-filter: blur(10px);
    padding: 40px 30px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.login-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15), 0 8px 20px rgba(0, 0, 0, 0.1);
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
    padding: 0 20px;
}

h2 {
    color: #333;
    font-size: 28px;
    font-weight: 600;
    margin-bottom: 30px;
    text-align: center;
    position: relative;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 2px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    color: #555;
    font-weight: 500;
    font-size: 14px;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 15px;
    transition: all 0.3s ease;
    background-color: rgba(255, 255, 255, 0.8);
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    background-color: white;
}

.form-group input:hover {
    border-color: #a0a0a0;
}

.btn {
    width: 100%;
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #5a6fd8 0%, #6a4090 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.alert {
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 8px;
    font-size: 14px;
    animation: slideIn 0.3s ease-out;
}

.alert-error {
    background-color: #fee;
    border: 1px solid #fcc;
    color: #c33;
}

.alert-success {
    background-color: #efe;
    border: 1px solid #cfc;
    color: #3c3;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .gradient-wrapper {
        padding-top: 20px;
        justify-content: center;
    }
    
    .login-box {
        margin: 20px;
        padding: 30px 20px;
    }
    
    h2 {
        font-size: 24px;
    }
    
    .form-group input {
        padding: 10px 12px;
        font-size: 14px;
    }
    
    .btn {
        padding: 10px 16px;
        font-size: 15px;
    }
}

@media (max-width: 480px) {
    .login-box {
        margin: 10px;
        padding: 25px 15px;
    }
    
    h2 {
        font-size: 22px;
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s ease-in-out infinite;
}

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

.form-group {
    position: relative;
}