/* 换图：修改下方变量，或直接替换 images/ 目录内同名文件 */
:root {
    --logo-url: url('../images/logo.webp');
    --bg-url: url('../images/bg.png');
}

html, body {
    height: 100%;
    margin: 0;
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

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

/* 顶栏：纯色背景，logo 不叠在 bg 上 */
.site-header {
    flex-shrink: 0;
    background: #fff;
    padding: 16px 0;
    border-bottom: 1px solid #eee;
}

.site-header .logo {
    max-height: 48px;
    width: auto;
}

/* 主区：仅此区域使用背景图 */
.hero-section {
    flex: 1;
    display: flex;
    align-items: center;
    padding: 50px 0;
    background-image: var(--bg-url);
    background-size: cover;
    background-position: center;
}

.content-text {
    color: #333;
    background: rgba(255, 255, 255, 0.8);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    max-width: 720px;
    margin: 0 auto;
}

.feature-list {
    list-style: none;
    padding-left: 0;
    margin-top: 20px;
}

.feature-list li {
    margin-bottom: 12px;
    font-size: 16px;
}

.feature-list li:before {
    content: '✓';
    color: #5cb85c;
    margin-right: 10px;
    font-weight: bold;
}

.site-footer {
    flex-shrink: 0;
    padding: 20px 0;
    text-align: center;
    background: rgba(0, 0, 0, 0.7);
    color: #fff;
}

.btn-download {
    display: block;
    margin: 20px auto 0;
    width: fit-content;
    font-size: 18px;
    padding: 12px 30px;
    border-radius: 30px;
    background-color: #007bff;
    border-color: #007bff;
}

.btn-download:hover {
    background-color: #0056b3;
    border-color: #004085;
    color: #fff;
}

@media (max-width: 767px) {
    .content-text {
        padding: 20px;
    }
}