* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", Arial, sans-serif;
}

/* 页面整体：上下布局 */
body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
.site-header {
    height: 70px;
    background: #fff;
    color: #C8161E;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 40px;
}

.logo {
    font-size: 22px;
    font-weight: bold;
}

.nav a {
    color: #fff;
    margin-left: 24px;
    text-decoration: none;
}

.nav a:hover {
    text-decoration: underline;
}

/* Main：左右布局 */
.main {
    flex: 1;                     /* 关键：占据剩余高度 */
    display: flex;
}

/* 每个项目块 */
.project {
    flex: 1;
    position: relative;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

/* 背景遮罩（50% 透明） */
.project::before {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
}

/* 内容 */
.content {
    position: relative;
    z-index: 1;
    max-width: 600px;
    text-align: center;
    padding: 40px;
}

.content h1 {
    font-size: 36px;
    margin-bottom: 20px;
}

.content p {
    font-size: 18px;
    margin-bottom: 30px;
    line-height: 1.6;
}

/* Button */
.btn {
    display: inline-block;
    padding: 14px 42px;
    background: #ff6a00;
    color: #fff;
    text-decoration: none;
    font-size: 18px;
}

.btn:hover {
    background: #ff8c42;
}

/* Footer */
.site-footer {
    height: 60px;
    background: #000;
    color: #aaa;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}

/* 本地背景图 */
.project-a {
    background-image: url("../png/leaderboard1.png");
}

.project-b {
    background-image: url("../png/airmind1.png");
}