:root{--color-bg-primary: #ffffff;--color-bg-secondary: #f5f5f7;--color-bg-tertiary: #fbfbfd;--color-text-primary: #1d1d1f;--color-text-secondary: #86868b;--color-accent: #0071e3;--color-accent-hover: #0077ed;--color-border: #d2d2d7;--color-card-bg: rgba(255, 255, 255, .8);--font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--font-size-xs: .75rem;--font-size-sm: .875rem;--font-size-base: 1rem;--font-size-lg: 1.125rem;--font-size-xl: 1.5rem;--font-size-2xl: 2rem;--font-size-3xl: 3rem;--font-size-4xl: 4rem;--spacing-xs: .5rem;--spacing-sm: 1rem;--spacing-md: 1.5rem;--spacing-lg: 2rem;--spacing-xl: 3rem;--spacing-2xl: 4rem;--radius-sm: 8px;--radius-md: 12px;--radius-lg: 20px;--radius-xl: 28px;--shadow-sm: 0 1px 3px rgba(0, 0, 0, .04);--shadow-md: 0 4px 12px rgba(0, 0, 0, .08);--shadow-lg: 0 8px 24px rgba(0, 0, 0, .12);--shadow-xl: 0 16px 48px rgba(0, 0, 0, .16);--transition-fast: .15s ease;--transition-base: .3s ease;--transition-slow: .5s ease}*{margin:0;padding:0;box-sizing:border-box}html{scroll-behavior:smooth}body{font-family:var(--font-family);background-color:var(--color-bg-primary);color:var(--color-text-primary);line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;overflow-x:hidden}.container{max-width:1200px;margin:0 auto;padding:0 var(--spacing-lg)}.section{padding:var(--spacing-2xl) 0}.navbar{position:sticky;top:0;z-index:1000;background:#ffffffb8;backdrop-filter:saturate(180%) blur(20px);-webkit-backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--color-border);transition:all var(--transition-base)}.navbar-content{display:flex;align-items:center;justify-content:space-between;padding:var(--spacing-sm) var(--spacing-lg);max-width:1990px;margin:0 auto}.navbar-logo{font-size:var(--font-size-2xl);font-weight:700;align-items:left;color:var(--color-text-primary);text-decoration:none;letter-spacing:-.03em}.navbar-links{display:flex;gap:var(--spacing-lg);list-style:none;align-items:center}.navbar-link{color:var(--color-text-primary);text-decoration:none;font-size:var(--font-size-base);font-weight:400;transition:color var(--transition-fast)}.navbar-link:hover{color:var(--color-accent)}.navbar-link.highlight{background:var(--color-accent);color:#fff;padding:8px 16px;border-radius:var(--radius-md);font-weight:600}.navbar-link.highlight:hover{background:var(--color-accent-hover);color:#fff}.hero{background:linear-gradient(180deg,var(--color-bg-tertiary) 0%,var(--color-bg-primary) 100%);padding:var(--spacing-2xl) 0;text-align:center}.hero-title{font-size:var(--font-size-4xl);font-weight:700;letter-spacing:-.03em;margin-bottom:var(--spacing-md);background:linear-gradient(135deg,var(--color-text-primary) 0%,var(--color-text-secondary) 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.hero-subtitle{font-size:var(--font-size-xl);color:var(--color-text-secondary);font-weight:400;max-width:600px;margin:0 auto var(--spacing-lg)}.hero-cta{display:inline-block;background-color:var(--color-accent);color:#fff;padding:12px 32px;font-size:var(--font-size-base);font-weight:600;text-decoration:none;border-radius:var(--radius-lg);border:none;cursor:pointer;transition:all var(--transition-base);margin-top:var(--spacing-md);box-shadow:var(--shadow-md)}.hero-cta:hover{background-color:var(--color-accent-hover);transform:translateY(-2px);box-shadow:var(--shadow-lg)}.hero-cta:active{transform:translateY(0)}.books-section{padding:var(--spacing-2xl) 0}.section-title{font-size:var(--font-size-2xl);font-weight:600;letter-spacing:-.02em;margin-bottom:var(--spacing-xl);text-align:center}.books-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:var(--spacing-lg);padding:0 var(--spacing-lg)}.book-card{background:var(--color-card-bg);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-radius:var(--radius-xl);border:1px solid var(--color-border);overflow:hidden;transition:all var(--transition-base);cursor:pointer}.book-card:hover{transform:translateY(-8px);box-shadow:var(--shadow-xl);border-color:var(--color-accent)}.book-cover{width:100%;height:400px;object-fit:cover;background:var(--color-bg-secondary)}.book-info{padding:var(--spacing-md)}.book-title{font-size:var(--font-size-lg);font-weight:600;margin-bottom:var(--spacing-xs);color:var(--color-text-primary);letter-spacing:-.01em}.book-author{font-size:var(--font-size-sm);color:var(--color-text-secondary);margin-bottom:var(--spacing-sm)}.book-rating{display:flex;align-items:center;gap:var(--spacing-xs);font-size:var(--font-size-sm);color:var(--color-text-secondary)}.stars{color:#ffb800}.footer{background:var(--color-bg-secondary);border-top:1px solid var(--color-border);padding:var(--spacing-xl) 0;margin-top:var(--spacing-2xl)}.footer-content{max-width:1200px;margin:0 auto;padding:0 var(--spacing-lg);text-align:center}.footer-text{color:var(--color-text-secondary);font-size:var(--font-size-sm)}.auth-page{min-height:80vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--color-bg-tertiary) 0%,#eef2f7 100%);padding:var(--spacing-2xl) var(--spacing-lg)}.login-card{background:var(--color-card-bg);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border:1px solid var(--color-border);border-radius:var(--radius-xl);padding:var(--spacing-2xl);width:100%;max-width:400px;box-shadow:var(--shadow-xl);animation:slideUp .6s ease}@keyframes slideUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}.auth-header{text-align:center;margin-bottom:var(--spacing-xl)}.auth-title{font-size:var(--font-size-2xl);font-weight:700;letter-spacing:-.02em;margin-bottom:var(--spacing-xs)}.auth-subtitle{color:var(--color-text-secondary);font-size:var(--font-size-sm)}.form-group{margin-bottom:var(--spacing-lg)}.form-group label{display:block;font-size:var(--font-size-xs);font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--color-text-secondary);margin-bottom:var(--spacing-xs)}.auth-input{width:100%;padding:14px 16px;border-radius:var(--radius-md);border:1px solid var(--color-border);background:#ffffff80;font-size:var(--font-size-base);transition:all var(--transition-base);outline:none}.auth-input:focus{border-color:var(--color-accent);background:#fff;box-shadow:0 0 0 4px #0071e31a}.auth-button{width:100%;padding:14px;border-radius:var(--radius-md);border:none;background:var(--color-accent);color:#fff;font-size:var(--font-size-base);font-weight:600;cursor:pointer;transition:all var(--transition-base);margin-top:var(--spacing-sm)}.auth-button:hover{background:var(--color-accent-hover);transform:translateY(-1px);box-shadow:var(--shadow-md)}.auth-footer{margin-top:var(--spacing-xl);text-align:center;font-size:var(--font-size-sm);color:var(--color-text-secondary)}.auth-link{color:var(--color-accent);text-decoration:none;font-weight:500}.auth-link:hover{text-decoration:underline}@media(max-width:768px){.hero-title{font-size:var(--font-size-3xl)}.hero-subtitle{font-size:var(--font-size-lg)}.books-grid{grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:var(--spacing-md)}.navbar-links{gap:var(--spacing-md)}.navbar-logo{font-size:var(--font-size-xl)}}@media(max-width:480px){.books-grid{grid-template-columns:1fr}.hero-title{font-size:var(--font-size-2xl)}}.modal-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:#0006;backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);display:flex;align-items:center;justify-content:center;z-index:2000;padding:var(--spacing-lg);animation:fadeIn .3s ease}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}.modal-close-btn{position:absolute;top:var(--spacing-sm);right:var(--spacing-sm);background:none;border:none;font-size:1.5rem;cursor:pointer;color:var(--color-text-secondary);transition:color var(--transition-fast)}.modal-close-btn:hover{color:var(--color-text-primary)}.bookshelf-section{padding:var(--spacing-2xl) 0;background:var(--color-bg-primary);min-height:60vh;display:flex;align-items:center}.bookshelf-container{max-width:1400px!important}.bookshelf-grid{display:flex;flex-wrap:wrap;gap:4px;justify-content:flex-start;width:1125px;align-items:flex-end;padding:var(--spacing-xl) 0;position:relative;margin-bottom:80px;max-width:1200px;margin-left:auto;margin-right:auto;background-image:var(--shelf-bg);background-size:100% 100%;background-repeat:no-repeat;background-position:center bottom;padding:75px 45px 45px}.shelf-book{position:relative;display:flex;flex-direction:column;align-items:center;transition:all var(--transition-base);cursor:pointer;width:65px;z-index:5}.shelf-book:hover{transform:translateY(-15px);z-index:10}.book-spine{width:100%;border-radius:3px;overflow:hidden;box-shadow:0 10px 25px #00000080;background-image:var(--spine-bg);background-size:100% 100%;background-position:center;position:relative;border:1px solid rgba(255,255,255,.1);transition:all var(--transition-base)}.shelf-book.small .book-spine{height:240px}.shelf-book.medium .book-spine{height:280px}.shelf-book.large .book-spine{height:320px}.shelf-book.xlarge .book-spine{height:360px}.spine-placeholder{width:100%;height:100%;display:flex;align-items:center;justify-content:center;padding:45px 5px 65px;position:relative;z-index:2}.spine-title{writing-mode:vertical-rl;transform:rotate(180deg);color:#2c1a1a;font-size:13px;font-weight:800;text-transform:uppercase;letter-spacing:.12em;text-align:center;opacity:.85;display:block;max-height:none;overflow:visible}.shelf-book:after{content:attr(data-tooltip);position:absolute;top:-50px;left:50%;transform:translate(-50%) translateY(10px);background:#fff;color:#1a1a1a;padding:8px 16px;border-radius:8px;font-size:13px;font-weight:500;white-space:nowrap;opacity:0;visibility:hidden;transition:all .3s ease;box-shadow:0 4px 20px #0006;z-index:100;pointer-events:none}.shelf-book:hover:after{opacity:1;visibility:visible;transform:translate(-50%) translateY(0)}.book-details-card{max-width:600px;padding:var(--spacing-xl)}.book-details-content{display:grid;grid-template-columns:200px 1fr;gap:var(--spacing-xl);margin-bottom:var(--spacing-xl)}.details-cover{width:100%;height:300px;object-fit:cover;border-radius:8px;box-shadow:var(--shadow-lg)}.details-placeholder{width:100%;height:300px;background:var(--color-bg-secondary);border-radius:8px;display:flex;align-items:center;justify-content:center;color:var(--color-text-tertiary);font-size:.9rem}.details-title{font-size:1.8rem;font-weight:700;color:var(--color-text-primary);margin-bottom:var(--spacing-xs);line-height:1.2}.details-author{font-size:1.1rem;color:var(--color-brand);margin-bottom:var(--spacing-md);font-weight:500}.details-meta{display:grid;gap:var(--spacing-sm);color:var(--color-text-secondary);font-size:.9rem}.details-meta p span{font-weight:600;color:var(--color-text-primary)}.delete-button{width:100%;padding:var(--spacing-md);background:transparent;color:#ef4444;border:1px solid #ef4444;border-radius:8px;font-weight:600;cursor:pointer;transition:all var(--transition-base);display:flex;align-items:center;justify-content:center;gap:var(--spacing-sm)}.delete-button:hover{background:#ef4444;color:#fff}@media(max-width:600px){.book-details-content{grid-template-columns:1fr}.details-cover,.details-placeholder{height:250px;width:180px;margin:0 auto}}.loading-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:var(--color-bg-primary);display:flex;align-items:center;justify-content:center;z-index:3000;animation:fadeOut .5s ease forwards}.spinner{width:50px;height:50px;border:3px solid rgba(0,113,227,.2);border-radius:50%;border-top-color:var(--color-accent);animation:spin 1s ease-in-out infinite}@keyframes spin{to{transform:rotate(360deg)}}@keyframes fadeOut{0%{opacity:1;visibility:visible}90%{opacity:0;visibility:visible}to{opacity:0;visibility:hidden}}.user-dropdown-container{position:relative;z-index:1100;display:flex;align-items:center}.user-dropdown-trigger{display:flex;align-items:center;gap:8px;cursor:pointer;padding:4px;border-radius:50px;background-color:transparent;transition:all .2s;-webkit-user-select:none;user-select:none;border:1px solid transparent}.user-dropdown-trigger:hover,.user-dropdown-trigger:active{background-color:var(--color-bg-secondary);border-color:var(--color-border)}.user-avatar{width:36px;height:36px;border-radius:50%;background:linear-gradient(135deg,#0071e3,#00c6ff);display:flex;align-items:center;justify-content:center;color:#fff;font-weight:600;font-size:14px;box-shadow:var(--shadow-sm)}.dropdown-menu{position:absolute;top:calc(100% + 12px);right:0;width:260px;background-color:var(--color-bg-primary);border:1px solid var(--color-border);border-radius:16px;box-shadow:0 4px 6px -1px #0000001a,0 2px 4px -1px #0000000f,0 10px 15px -3px #0000001a;padding:6px;display:none;flex-direction:column;color:var(--color-text-primary);font-family:var(--font-family);animation:slideDownFade .2s ease-out}.dropdown-menu.active{display:flex}@keyframes slideDownFade{0%{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}.dropdown-header{padding:12px;border-bottom:1px solid var(--color-border);margin-bottom:4px}.user-name-display{font-weight:600;font-size:14px;color:var(--color-text-primary);margin-bottom:2px}.user-email-display{font-size:12px;color:var(--color-text-secondary)}.dropdown-item{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;border-radius:6px;cursor:pointer;font-size:13px;color:var(--color-text-primary);text-decoration:none;transition:all .2s}.dropdown-item:hover{background-color:var(--color-bg-secondary);color:var(--color-text-primary)}.dropdown-item-content{display:flex;align-items:center;gap:10px}.dropdown-divider{height:1px;background-color:var(--color-border);margin:6px 0}.kbd-shortcut{display:inline-flex;align-items:center;gap:4px;font-family:monospace;font-size:10px;color:var(--color-text-secondary);border:1px solid var(--color-border);border-radius:4px;padding:2px 4px}.theme-toggle-row{display:flex;align-items:center;justify-content:space-between}.theme-options{display:flex;background:var(--color-bg-secondary);border-radius:8px;padding:3px;gap:2px}.theme-option-btn{width:28px;height:28px;display:flex;align-items:center;justify-content:center;border-radius:6px;cursor:pointer;color:var(--color-text-secondary);transition:all .2s ease;font-size:14px}.theme-option-btn:hover{color:var(--color-text-primary);background-color:#0000000d}.theme-option-btn.active{background:#fff;box-shadow:0 1px 3px #0000001a;color:#000}.upgrade-btn{margin-top:4px;background:#111;color:#fff;border:none;border-radius:8px;padding:10px;font-weight:600;font-size:13px;cursor:pointer;text-align:center;transition:all .2s;font-family:var(--font-family)}.upgrade-btn:hover{background:#000;transform:translateY(-1px);box-shadow:0 4px 12px #00000026}