:root{--sidebar-bg: #1a1a2e;--sidebar-text: #8892b0;--sidebar-active: #ffd369;--sidebar-hover: #e8ecf1;--main-bg: #f8f9fb;--main-text: #2c3e50;--main-muted: #6b7280;--accent-blue: #4f6ef6;--accent-gold: #f59e0b;--accent-purple: #8b5cf6;--card-bg: #ffffff;--card-border: #e8ecf1;--card-radius: 12px;--card-shadow: 0 1px 4px rgba(0,0,0,.06);--memory-bg-start: #fffbeb;--memory-bg-end: #fef3c7;--memory-border: #fcd34d;--sidebar-width: 260px;--content-max: 1080px;--header-height: 56px;--font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;--font-mono: "Cascadia Code", "Fira Code", "Consolas", monospace}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{font-size:16px;scroll-behavior:smooth}body{font-family:var(--font-sans);color:var(--main-text);background:var(--main-bg);line-height:1.7;-webkit-font-smoothing:antialiased}a{color:var(--accent-blue);text-decoration:none}a:hover{text-decoration:underline}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#c1c9d2;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#a0aab5}.book-container{display:flex;justify-content:center;align-items:center;min-height:calc(100vh - var(--header-height));padding:2rem;perspective:2000px}.book-spread{display:flex;width:100%;max-width:var(--content-max);min-height:600px;background:var(--card-bg);border-radius:var(--card-radius);box-shadow:var(--card-shadow),0 8px 32px #00000014;overflow:hidden}.page{flex:1;padding:3rem 2.5rem;background:var(--card-bg);transform-origin:left center;transition:transform .6s cubic-bezier(.4,0,.2,1);position:relative}.page.right{transform-origin:right center;border-left:1px solid var(--card-border)}.page.turning{transform:rotateY(-180deg);box-shadow:-8px 0 24px #0000001f;z-index:10}.page.right.turning{transform:rotateY(180deg)}.page.turning .page-content{transform:scaleX(-1);opacity:.3}.page-number{position:absolute;bottom:1.5rem;font-size:.8rem;color:var(--main-muted)}.page-number.left{left:2.5rem}.page-number.right{right:2.5rem}.page-nav{display:flex;justify-content:center;gap:1rem;padding:1rem}.page-nav button{padding:.5rem 1.25rem;border:1px solid var(--card-border);border-radius:8px;background:var(--card-bg);color:var(--main-text);font-size:.9rem;cursor:pointer;transition:all .2s}.page-nav button:hover{background:var(--accent-blue);color:#fff;border-color:var(--accent-blue)}.page-nav button:disabled{opacity:.4;cursor:not-allowed}.page-nav button:disabled:hover{background:var(--card-bg);color:var(--main-text);border-color:var(--card-border)}