/* 全局样式 */
body {
    font-family: 'Helvetica Neue', 'Segoe UI', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #fdfdfd;
    color: #333;
    line-height: 1.6;
}

/* 页眉 */
header {
    text-align: center;
    padding: 30px 20px 10px; /* 缩短顶部和底部，使 h1 和导航更紧凑 */
    background: #ffffff;
    border-bottom: 1px solid #eee;
}

header h1 {
    margin: 0 0 5px 0;      /* 底部间距缩短 */
    font-size: 3rem;
    font-weight: 700;
    color: #222;
    letter-spacing: 1px;
    position: relative;
    display: inline-block;
    padding-bottom: 12px;
}

/* h1 下划线点缀 */
header h1::after {
    content: "";
    display: block;
    width: 60%;
    height: 3px;
    margin: 12px auto 0;
    background: linear-gradient(90deg, #4facfe, #00f2fe);
    border-radius: 2px;
}

header p {
    margin-top: 8px;         /* 缩小与 h1 的间距 */
    font-size: 1.2rem;
    color: #666;
}

/* 国家链接区 */
.top-countries {
    text-align: center;
    margin: 10px auto;        /* 缩短与 header 的距离 */
}

.top-countries a {
    display: inline-block;
    margin: 6px 10px;
    padding: 8px 14px;
    background: #f5f7fa;
    border: 1px solid #e0e0e0;
    border-radius: 6px;
    color: #0072ff;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
}

.top-countries a:hover {
    background: #0072ff;
    color: white;
    border-color: #0072ff;
}

/* 内容区块 */
section {
    max-width: 900px;
    margin: 30px auto;         /* 缩短上下间距 */
    padding: 25px;             /* 缩短内边距 */
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

section:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 25px rgba(0,0,0,0.12);
}

/* h2 标题 */
h2 {
    font-size: 1.8rem;
    margin-top: 12px;          /* 缩短与上方内容间距 */
    margin-bottom: 8px;        /* 缩短与下方内容间距 */
    color: #222;
    font-weight: 600;
}

/* 段落 */
p {
    font-size: 1rem;
    margin-bottom: 16px;       /* 缩短段落底部间距 */
    color: #555;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    text-decoration: none;
    border-radius: 8px;
    background: linear-gradient(90deg, #4facfe, #00f2fe);
    box-shadow: 0 4px 12px rgba(0, 114, 255, 0.3);
    transition: all 0.3s ease;
}

.btn:hover {
    background: linear-gradient(90deg, #00f2fe, #4facfe);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 114, 255, 0.4);
}

/* 响应式 */
@media (max-width: 768px) {
    header h1 {
        font-size: 2.2rem;
    }

    h2 {
        font-size: 1.4rem;
    }

    section {
        margin: 20px;
        padding: 20px;
    }
}


/* 页脚样式 */
footer {
    text-align: center;       /* 居中对齐 */
    padding: 20px 0;          /* 上下留白 */
    font-size: 14px;          /* 字体稍小 */
    color: #aaa;              /* 使用低调的灰色 */
    background: #0f0f0f;      /* 与整体风格一致的深色背景 */
    border-top: 1px solid #222; /* 顶部加一条细线，提升层次感 */
}

footer p {
    margin: 0;                /* 去掉段落默认间距 */
}