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

body {
    background-image: url(../img/bgimg.jpeg);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

#login-box {
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    text-align: center;
    margin: 0 auto;
    padding: 40px 30px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.6s ease-in-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

#login-box h1 {
    color: #ffffff;
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.subtitle {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1rem;
    margin-bottom: 30px;
}

.section {
    margin-bottom: 35px;
}

.section-title {
    color: #ffffff;
    font-size: 1.3rem;
    margin-bottom: 20px;
    text-align: left;
    padding-left: 10px;
    border-left: 4px solid #a6c0fe;
    font-weight: 600;
}

.button-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 15px;
    margin-bottom: 10px;
}

.btn-link {
    text-decoration: none;
}

.project-btn {
    width: 100%;
    padding: 18px 20px;
    border-radius: 15px;
    outline: none;
    border: none;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #FFFFFF;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.btn-icon {
    font-size: 1.8rem;
    display: block;
}

.btn-text {
    font-size: 0.95rem;
}

.project-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.project-btn:active {
    transform: translateY(-2px);
}

footer {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
}

.beian-link {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.beian-link:hover {
    color: rgba(255, 255, 255, 1);
}

/* 响应式设计 */
@media (max-width: 768px) {
    #login-box {
        padding: 30px 20px;
    }

    #login-box h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.1rem;
    }

    .button-grid {
        grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
        gap: 12px;
    }

    .project-btn {
        padding: 15px 15px;
    }

    .btn-icon {
        font-size: 1.5rem;
    }

    .btn-text {
        font-size: 0.85rem;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }

    #login-box {
        padding: 25px 15px;
    }

    #login-box h1 {
        font-size: 1.8rem;
    }

    .button-grid {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }
}