:root {
    --primary-color: #2c3e50;  /* 品牌深蓝色 */
    --accent-color: #3498db;   /* 品牌亮蓝色 */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, sans-serif;
}

/* 头部样式 */
header {
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    height: 40px;
}

nav a {
    text-decoration: none;
    color: var(--primary-color);
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s;
}

nav a:hover {
    color: var(--accent-color);
}

/* 登录表单容器 */
.login-container {
    min-height: 70vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem 5%;
    background: #f8f9fa;
}

.login-box {
    background: white;
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    width: 100%;
    max-width: 450px;
}

.form-title {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.input-group {
    margin-bottom: 1.2rem;
}

input {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

input:focus {
    outline: none;
    border-color: var(--accent-color);
}

.remember-forgot {
    display: flex;
    justify-content: space-between;
    margin: 1rem 0;
    font-size: 0.9rem;
}

.login-btn {
    width: 100%;
    padding: 0.9rem;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s;
}

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

/* 底部样式 */
footer {
    background: var(--primary-color);
    color: white;
    padding: 2rem 5%;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: #bdc3c7;
    text-decoration: none;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }

    nav {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }

    nav a {
        margin-left: 0;
        font-size: 0.9rem;
    }

    .login-box {
        padding: 1.5rem;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.8rem;
    }
}