/* 导航栏整体 */
.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
}
.logo {
    font-size: 1.5em;
    font-weight: bold;
    color: #4285f4;
}
.nav-menu {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}
.nav-menu li {
    position: relative;
}
.nav-menu a {
    text-decoration: none;
    color: #333;
    font-size: 1.08em;
    padding: 8px 12px;
    border-radius: 6px;
    transition: background 0.2s;
}
.nav-menu a:hover {
    background: #e3eafc;
}
.dropdown-menu {
    position: absolute;
    top: 38px;
    left: 0;
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(66,133,244,0.08);
    padding: 8px 0;
    min-width: 160px;
    z-index: 10;
    display: none;
    flex-direction: column;
}
.dropdown:hover .dropdown-menu,
.dropdown-menu.show {
    display: flex;
}
.dropdown-arrow {
    margin-left: 6px;
    font-size: 0.9em;
    transition: transform 0.2s;
}

nav {
    width: 100%;
    border-bottom: 1px solid #e0e0e0;
    top: 0;
}

/* 导航内容容器 */
nav > div {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
}

/* Logo */
nav .logo {
    font-size: 1.6em;
    font-weight: bold;
    color: #4285f4;
    padding: 18px 0;
}

/* 导航菜单 */
nav ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

/* 导航链接 */
nav ul li a {
    text-decoration: none;
    color: #333;
    font-size: 1.1em;
    user-select: none;
}

/* 下拉菜单父项 */
nav ul li {
    position: relative;
}

/* 下拉菜单三角 */
nav ul li .dropdown-arrow {
    display: inline-block;
    transition: transform 0.2s;
}

/* 下拉菜单 */
nav ul li ul {
    position: absolute;
    top: 2em;
    left: 0;
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(66,133,244,0.08);
    padding: 8px 0;
    min-width: 160px;
    z-index: 10;
}
.nav-menu a:hover {
    background: #e3eafc;
}
.nav-menu a {
    text-decoration: none;
    color: #333;
    font-size: 1.08em;
    padding: 8px 12px;
    border-radius: 6px;
    transition: background 0.2s;
}

/* 修正下拉菜单为竖向排列 */
.dropdown-menu {
    display: block;
    position: absolute;
    top: 2em;
    left: 0;
    background: #fff;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(66,133,244,0.08);
    padding: 8px 0;
    min-width: 160px;
    z-index: 10;
    flex-direction: column; /* 保证竖向排列 */
}

.dropdown-menu li {
    display: block;
    width: 100%;
}

.dropdown-menu li a {
    display: block;
    padding: 8px 24px;
    color: #333;
    text-decoration: none;
    width: 100%;
    box-sizing: border-box;
}

/* 主体内容 */
main {
    max-width: 900px;
    margin: 48px auto 32px auto;
    padding: 0 24px;
}

main h1 {
    font-size: 2.2em;
    color: #4285f4;
    margin-bottom: 16px;
}

main p {
    font-size: 1.2em;
    color: #444;
    line-height: 1.7;
}

main ul {
    font-size: 1.1em;
    color: #444;
    line-height: 1.7;
    margin-top: 24px;
}

main ul li {
    margin-bottom: 8px;
}

main .get-started {
    margin-top: 32px;
    font-size: 1.1em;
    color: #555;
}

/* 主体分区样式 */
.section {
    max-width: 900px;
    margin: 0 auto 40px auto;
    padding: 32px 24px;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 2px 12px rgba(66,133,244,0.06);
}

.section.overview {
    margin-top: 40px;
    background: #f7f9fa;
    box-shadow: none;
}

.feature {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    border-top: 3px solid #e0e0e0;
}

.feature-text {
    flex: 1;
}

.feature-text h2 {
    font-size: 1.6em;
    color: #4285f4;
    margin-bottom: 12px;
}

.feature-text p {
    font-size: 1.15em;
    color: #444;
    line-height: 1.7;
}

.feature-img {
    flex: 1;
    min-width: 220px;
    max-width: 320px;
    height: 160px;
    border-radius: 12px;
    margin-left: 24px;
    box-shadow: 0 2px 8px rgba(66,133,244,0.10);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 用不同色块代替图片 */
.mindmap-img { background: linear-gradient(135deg, #81c784 0%, #4fc3f7 100%); }
.flowchart-img { background: linear-gradient(135deg, #ffd54f 0%, #ff8a65 100%); }
.eventmap-img { background: linear-gradient(135deg, #ba68c8 0%, #64b5f6 100%); }
.timeline-img { background: linear-gradient(135deg, #ffb74d 0%, #90caf9 100%); }
.mermaid-img { background: linear-gradient(135deg, #26c6da 0%, #ab47bc 100%); }

/* 尾页/版权信息 */
footer {
    width: 100%;
    background: #f7f9fa;
    border-top: 1px solid #e0e0e0;
    padding: 18px 0;
    text-align: center;
    color: #888;
    font-size: 1em;
}

/* 尾页分区样式 */
.footer-section {
    width: 100%;
    background: #e3eafc;
    border-top: 1px solid #cfd8dc;
    padding: 10px 0;
    text-align: center;
    color: #888;
    font-size: 0.95em;
    letter-spacing: 1px;
    margin-top: 48px;
}

.feature-btn {
    display: inline-block;
    margin-top: 18px;
    padding: 8px 28px;
    background: #4285f4;
    color: #fff;
    font-size: 1.08em;
    border: none;
    border-radius: 8px;
    text-decoration: none;
    box-shadow: 0 2px 8px rgba(66,133,244,0.10);
    transition: background 0.2s;
    cursor: pointer;
}
.feature-btn:hover {
    background: #1565c0;
}