/* 全局样式 */
body {
    font-family: "Microsoft YaHei", Arial, sans-serif;
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.8;
    margin: 0;
    padding: 0;
}

/* 容器通用样式（替代Bootstrap） */
.container-fluid {
    width: 100%;
}
.text-center {
    text-align: center;
}
.img-fluid {
    max-width: 100%;
    height: auto;
}
.mt-3 {
    margin-top: 1rem;
}
.mt-4 {
    margin-top: 1.5rem;
}
.mt-5 {
    margin-top: 3rem;
}

/* 头部横幅 */
.header-banner {
    background-color: #2c3e50;
    padding: 15px 0;
    text-align: center;
    margin-bottom: 20px;
}
.header-banner img {
    max-height: 500px;
}
.header-banner .mt-3 img {
    max-height: 120px;
}

/* 内容容器 */
.content-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 30px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
}

/* 标题样式 */
h1 {
    color: #c0392b;
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 20px;
    border-bottom: 3px solid #e74c3c;
    padding-bottom: 10px;
}
h2 {
    color: #2980b9;
    font-size: 1.8rem;
    margin: 30px 0 15px;
    border-left: 5px solid #2980b9;
    padding-left: 15px;
}
h3 {
    color: #8e44ad;
    font-size: 1.5rem;
    margin: 25px 0 10px;
}

/* 列表样式 */
.content-list {
    list-style: none;
    padding-left: 0;
}
.content-list li {
    margin-bottom: 15px;
    padding-left: 20px;
    position: relative;
}
.content-list li::before {
    content: "★";
    color: #e74c3c;
    position: absolute;
    left: 0;
}

/* 链接样式 */
a {
    color: #e74c3c;
    text-decoration: none;
    transition: all 0.3s ease;
}
a:hover {
    color: #c0392b;
    text-decoration: underline;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    cursor: pointer;
    text-align: center;
    user-select: none;
    border: none;
    transition: all 0.3s ease;
}
.btn-join {
    background-color: #e74c3c;
    color: #fff;
    padding: 12px 30px;
    border-radius: 50px;
    font-size: 1.2rem;
    font-weight: bold;
    margin-top: 20px;
}
.btn-join:hover {
    background-color: #c0392b;
    color: #fff;
    transform: scale(1.05);
    text-decoration: none;
}

/* 页脚样式 */
footer {
    text-align: center;
    padding: 20px;
    margin-top: 30px;
    color: #777;
    font-size: 0.9rem;
}

/* iframe 样式 */
.ifindex {
    display: block;
    max-width: 1200px;
    margin: 0 auto;
}
.ifindex:nth-of-type(2) {
    margin: 10px auto !important;
}

/* 响应式适配 */
@media (max-width: 768px) {
    .content-container {
        padding: 15px;
    }
    h1 {
        font-size: 2rem;
    }
    h2 {
        font-size: 1.5rem;
    }
}