:root {
    --primary: #1a1a1a;
    --accent: #b08d5c;
    --bg: #f9f7f2;
    --card-bg: #ffffff;
    --text-muted: #888;
    --transition: all 0.5s cubic-bezier(0.23, 1, 0.32, 1);
}

body {
    background-color: var(--bg);
    color: var(--primary);
    font-family: 'PingFang SC', sans-serif;
    margin: 0;
    line-height: 1.6;
}

/* 导航 */
nav {
    display: flex; justify-content: space-between; align-items: center;
    padding: 1.5rem 8%; background: rgba(255,255,255,0.8);
    backdrop-filter: blur(15px); position: sticky; top: 0; z-index: 100;
}
.logo { font-size: 1.4rem; font-weight: 800; color: var(--primary); text-decoration: none; letter-spacing: 2px; }

/* Hero */
.hero { padding: 8rem 5% 4rem; text-align: center; }
.hero h1 { font-size: 3.5rem; margin-bottom: 1rem; font-family: serif; font-weight: 900; }

/* 统计栏 */
.stats-bar { display: flex; justify-content: center; gap: 4rem; margin-bottom: 5rem; }
.stat-item { text-align: center; font-size: 0.9rem; color: var(--text-muted); }
.stat-item span { display: block; font-size: 2rem; font-weight: bold; color: var(--accent); }

/* 书架网格 */
.book-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 4rem; padding: 0 8% 5rem; }

/* 书籍卡片 */
.book-card {
    background: var(--card-bg); padding: 25px; border-radius: 24px;
    text-decoration: none; color: inherit; transition: var(--transition);
    box-shadow: 0 10px 40px rgba(0,0,0,0.03); opacity: 0; transform: translateY(40px);
}
.book-card.visible { opacity: 1; transform: translateY(0); }
.book-card:hover { transform: translateY(-15px); box-shadow: 0 30px 60px rgba(0,0,0,0.08); }

.book-cover-wrapper {
    position: relative; height: 420px; border-radius: 16px; overflow: hidden;
    margin-bottom: 1.5rem; box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}
.book-cover { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
.book-card:hover .book-cover { transform: scale(1.08); }

.badge {
    position: absolute; top: 15px; left: 15px; background: rgba(0,0,0,0.6);
    backdrop-filter: blur(5px); color: white; padding: 6px 14px;
    border-radius: 50px; font-size: 0.75rem;
}

.progress-container { margin-top: 15px; height: 4px; background: #eee; border-radius: 10px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--accent); border-radius: 10px; }

/* 动画 */
.animate-in { opacity: 0; transform: translateY(20px); animation: fadeIn 0.8s forwards; }
@keyframes fadeIn { to { opacity: 1; transform: translateY(0); } }

footer { text-align: center; padding: 4rem; color: var(--text-muted); font-size: 0.9rem; border-top: 1px solid #eee; }