/* 引入自定义英文字体 */
@font-face {
    font-family: 'YiMengFont';
    src: url('../font/a.ttf') format('truetype');
    font-display: swap;
}

/* 全局重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
    background: linear-gradient(145deg, #f1eeff 0%, #edf1fc 50%, #e6ecf8 100%);
    background-attachment: fixed;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* 导航栏 */
.nav-header {
    position: fixed;
    top: 20px;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: center;
    z-index: 1000;
}

.nav-capsule {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 6px 24px 6px 6px;
    border-radius: 50px;
    box-shadow: 0 8px 32px rgba(100, 100, 150, 0.08);
}

.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    margin-right: 12px;
}

.nav-brand {
    font-family: 'YiMengFont', serif;
    font-size: 20px;
    font-weight: bold;
    color: #1a1e29;
    letter-spacing: 1px;
}

/* 首屏 Hero */
.hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: relative;
    padding: 0 20px;
}

.hero-title {
    font-family: 'YiMengFont', serif;
    font-size: 72px;
    color: #27479f; /* 核心深蓝色 */
    margin-bottom: 24px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 16px;
    color: #6b7280;
    line-height: 1.8;
}

.scroll-down {
    position: absolute;
    bottom: 50px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    opacity: 0.6;
}

.scroll-down span {
    font-size: 11px;
    letter-spacing: 2px;
    color: #888;
    text-transform: uppercase;
}

.scroll-line {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, #a0a0a0, transparent);
}

/* 项目区块共用样式 */
.project-section {
    padding: 80px 20px;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.tag {
    display: inline-block;
    background: #e4ebfb;
    color: #4b6bfb;
    font-size: 12px;
    font-weight: 600;
    padding: 6px 16px;
    border-radius: 20px;
    letter-spacing: 1px;
    margin-bottom: 20px;
}

.section-title {
    font-size: 28px;
    color: #111827;
    margin-bottom: 40px;
    font-weight: 700;
}

/* 卡片与图片 */
.project-card {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.project-image {
    width: 100%;
    max-width: 600px;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.06);
    margin-bottom: 30px;
}

.app-icon {
    width: 180px;
    height: 180px;
    border-radius: 40px;
    box-shadow: 0 16px 32px rgba(255, 182, 193, 0.2);
    margin-bottom: 30px;
    object-fit: cover;
}

.project-name {
    font-family: -apple-system, sans-serif;
    font-size: 32px;
    color: #1a1e29;
    margin-bottom: 8px;
    font-weight: 700;
}

.project-category {
    font-size: 14px;
    color: #4b6bfb;
    margin-bottom: 20px;
    font-weight: 500;
}

.project-desc {
    font-size: 15px;
    color: #6b7280;
    max-width: 420px;
    margin: 0 auto 30px auto;
    line-height: 1.8;
}

/* 按钮组 */
.button-group {
    display: flex;
    gap: 16px;
    justify-content: center;
}

.btn {
    display: flex;
    align-items: center;
    gap: 8px;
    background: #ffffff;
    color: #1a1e29;
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 14px;
    font-weight: 500;
    box-shadow: 0 8px 24px rgba(0,0,0,0.04);
    transition: all 0.3s ease;
}

.btn svg {
    width: 18px;
    height: 18px;
}

.btn:hover {
    box-shadow: 0 12px 32px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

/* 底部 Footer */
.footer {
    padding: 80px 40px 40px 40px;
    max-width: 800px;
    margin: 40px auto 0 auto;
    text-align: left;
}

.footer-brand {
    font-family: 'YiMengFont', serif;
    font-size: 36px;
    color: #111827;
    margin-bottom: 16px;
}

.footer-slogan {
    font-size: 14px;
    color: #6b7280;
    line-height: 1.8;
    margin-bottom: 40px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 60px;
    margin-bottom: 60px;
}

.link-column h3 {
    font-size: 16px;
    color: #111827;
    margin-bottom: 20px;
    font-weight: 600;
}

.link-column ul {
    list-style: none;
}

.link-column ul li {
    margin-bottom: 16px;
    font-size: 14px;
    color: #6b7280;
    display: flex;
    align-items: center;
    gap: 10px;
}

.link-column ul li a {
    color: #6b7280;
    text-decoration: none;
    transition: color 0.3s;
}

.link-column ul li a:hover {
    color: #27479f;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid rgba(0,0,0,0.05);
    padding-top: 24px;
}

.footer-bottom p {
    font-size: 13px;
    color: #9ca3af;
}

.back-to-top {
    background: none;
    border: none;
    font-size: 13px;
    color: #111827;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    font-weight: 500;
}

/* --- 绝对流畅的滚动渐现动画 (核心) --- */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.9s cubic-bezier(0.16, 1, 0.3, 1); /* 使用极平滑的缓动曲线 */
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* 顶部导航向下渐现 */
.reveal-down {
    opacity: 0;
    transform: translateY(-30px);
    transition: all 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-down.active {
    opacity: 1;
    transform: translateY(0);
}

/* 移动端适配调整 */
@media (max-width: 600px) {
    .hero-title { font-size: 60px; }
    .footer-links { gap: 40px; flex-direction: column; }
    .footer-bottom { flex-direction: column; gap: 20px; align-items: flex-start;}
}