/* CSS 样式代码块 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: #fff;
    background: linear-gradient(to bottom, #0f1c3f, #1a295f);
    overflow-x: hidden;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

header .logo {
    font-size: 24px;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: #00ffff;
}

header nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

header nav ul li a {
    text-decoration: none;
    color: #fff;
    font-size: 16px;
    transition: color 0.3s ease;
}

header nav ul li a:hover {
    color: #00ffff;
}

.fullscreen-container {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
    background: linear-gradient(to bottom, #000, #1e1e1e);
    position: relative;
}

.fullscreen-container h1 {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 255, 255, 0.5);
}

.fullscreen-container p {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 40px;
}

button.cta {
    background: #00ffff;
    color: #000;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

button.cta:hover {
    transform: scale(1.1);
    box-shadow: 0 5px 15px rgba(0, 255, 255, 0.5);
}

.section {
    padding: 60px 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: linear-gradient(to bottom, #1a295f, #0f1c3f);
    position: relative;
}

.section:nth-child(even) {
    background: linear-gradient(to bottom, #0f1c3f, #1a295f);
}

.section h2 {
    font-size: 36px;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 255, 255, 0.5);
}

.section p {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 40px;
}

.parallax-background {
    background-image: url('https://images.gptkong.com/demo/sample1.png');
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    height: 50vh;
    width: 100%;
    position: relative;
    margin-top: -40px;
}

@media (max-width: 768px) {
    header {
        padding: 15px 20px;
    }

    header .logo {
        font-size: 20px;
    }

    header nav ul li a {
        font-size: 14px;
    }

    .fullscreen-container h1 {
        font-size: 36px;
    }

    .section h2 {
        font-size: 28px;
    }
}

@media (max-width: 480px) {
    .fullscreen-container h1 {
        font-size: 28px;
    }

    .section h2 {
        font-size: 24px;
    }
}