/* ========================================================= VARIABLES ========================================================= */
 .theme-dark, .theme-light {
     --transition-theme: 420ms cubic-bezier(0.22, 1, 0.36, 1);
     --blur: 22px;
     --blur-strong: 32px;
     --radius-sm: 12px;
     --radius-md: 18px;
     --radius-lg: 24px;
     --radius-xl: 30px;
     --accent: #0a84ff;
     --accent-secondary: #5e5ce6;
     --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
/* ========================================================= DARK ========================================================= */
 .theme-dark {
     --bg: #050507;
     --glass: rgba(255, 255, 255, 0.055);
     --glass-strong: rgba(255, 255, 255, 0.085);
     --glass-hover: rgba(255, 255, 255, 0.11);
     --border: rgba(255, 255, 255, 0.105);
     --border-strong: rgba(255, 255, 255, 0.17);
     --text: #f7f7f8;
     --text-secondary: rgba(247, 247, 248, 0.70);
     --text-muted: rgba(247, 247, 248, 0.45);
     --shadow: rgba(0, 0, 0, 0.22);
     --ambient-one: rgba(65, 105, 190, 0.20);
     --ambient-two: rgba(94, 92, 230, 0.14);
     --ambient-three: rgba(10, 132, 255, 0.07);
}
/* ========================================================= LIGHT ========================================================= */
 .theme-light {
     --bg: #f3f5f8;
     --glass: rgba(255, 255, 255, 0.52);
     --glass-strong: rgba(255, 255, 255, 0.72);
     --glass-hover: rgba(255, 255, 255, 0.86);
     --border: rgba(255, 255, 255, 0.72);
     --border-strong: rgba(255, 255, 255, 0.95);
     --text: #17181c;
     --text-secondary: rgba(23, 24, 28, 0.68);
     --text-muted: rgba(23, 24, 28, 0.43);
     --shadow: rgba(30, 40, 60, 0.12);
     --ambient-one: rgba(110, 160, 255, 0.24);
     --ambient-two: rgba(160, 140, 255, 0.15);
     --ambient-three: rgba(80, 180, 255, 0.09);
}
/* ========================================================= RESET ========================================================= */
 * {
     box-sizing: border-box;
}
 html {
     min-height: 100%;
     background: var(--bg);
}
 body {
     margin: 0;
     min-height: 100vh;
     font-family: var(--font);
     color: var(--text);
     background: radial-gradient( 900px 500px at 10% -10%, var(--ambient-one), transparent 65% ), radial-gradient( 750px 500px at 90% 0%, var(--ambient-two), transparent 65% ), radial-gradient( 800px 700px at 50% 100%, var(--ambient-three), transparent 70% ), var(--bg);
     background-attachment: fixed;
     transition: background-color var(--transition-theme), color var(--transition-theme);
}
 button, input {
     font: inherit;
}
 button {
     cursor: pointer;
}
 a {
     color: inherit;
     text-decoration: none;
}
/* ========================================================= AMBIENT LIGHT ========================================================= */
 .ambient {
     position: fixed;
     width: 500px;
     height: 500px;
     border-radius: 50%;
     pointer-events: none;
     filter: blur(100px);
     opacity: 0.22;
     z-index: -1;
     transition: background-color var(--transition-theme);
}
 .ambient-one {
     top: -300px;
     left: -200px;
     background: var(--ambient-one);
}
 .ambient-two {
     top: -200px;
     right: -200px;
     background: var(--ambient-two);
}
 .ambient-three {
     bottom: -350px;
     left: 35%;
     background: var(--ambient-three);
}
/* ========================================================= HEADER ========================================================= */
 .site-header {
     position: sticky;
     top: 0;
     z-index: 50;
     padding: 14px 24px;
     background: var(--glass-strong);
     backdrop-filter: blur(28px) saturate(160%);
     -webkit-backdrop-filter: blur(28px) saturate(160%);
     border-bottom: 1px solid var(--border);
     box-shadow: 0 10px 35px var(--shadow);
     transition: background-color 220ms ease, border-color 220ms ease;
}
 .header-inner {
     max-width: 1240px;
     margin: 0 auto;
     display: flex;
     align-items: center;
     justify-content: space-between;
     gap: 20px;
}
/* ========================================================= BRAND ========================================================= */
 .brand {
     display: flex;
     align-items: center;
     gap: 12px;
}
 .avatar {
     width: 42px;
     height: 42px;
     border-radius: 50%;
     object-fit: cover;
     border: 1px solid var(--border-strong);
     box-shadow: 0 5px 18px var(--shadow);
}
 .brand-text {
     display: flex;
     flex-direction: column;
     gap: 1px;
}
 .brand-name {
     font-size: 0.95rem;
     font-weight: 700;
     letter-spacing: -0.02em;
}
 .brand-subtitle {
     font-size: 0.72rem;
     color: var(--text-muted);
}
/* ========================================================= HEADER RIGHT ========================================================= */
 .header-right {
     display: flex;
     align-items: center;
     gap: 12px;
}
/* ========================================================= WORK COUNT ========================================================= */
 .works-count {
     position: relative;
     display: flex;
     align-items: center;
     justify-content: center;
     width: 72px;
     height: 72px;
     border-radius: 50%;
     background: radial-gradient( circle at 30% 23%, rgba(255,255,255,.18), transparent 28% ), var(--glass-strong);
     border: 1px solid var(--border-strong);
     backdrop-filter: blur(24px) saturate(160%);
     -webkit-backdrop-filter: blur(24px) saturate(160%);
     box-shadow: inset 0 1px 1px rgba(255,255,255,.12), inset 0 -12px 25px rgba(0,0,0,.08), 0 12px 40px var(--shadow);
     transition: transform 220ms ease, box-shadow 220ms ease, background-color 220ms ease;
}
 .works-count:hover {
     transform: translateY(-2px);
     box-shadow: inset 0 1px 1px rgba(255,255,255,.15), 0 16px 45px rgba(10,132,255,.13);
}
 .works-count div {
     display: flex;
     flex-direction: column;
     align-items: center;
     line-height: 1;
}
 .works-count strong {
     font-size: 1.15rem;
     font-weight: 700;
}
 .works-count span {
     margin-top: 4px;
     font-size: .62rem;
     color: var(--text-muted);
}
/* ========================================================= THEME BUTTON ========================================================= */
 .theme-toggle {
     width: 42px;
     height: 42px;
     display: flex;
     align-items: center;
     justify-content: center;
     border-radius: 50%;
     border: 1px solid var(--border);
     background: var(--glass);
     color: var(--text);
     backdrop-filter: blur(18px);
     -webkit-backdrop-filter: blur(18px);
     transition: background-color 220ms ease, transform 220ms ease, border-color 220ms ease;
}
 .theme-toggle:hover {
     background: var(--glass-hover);
     transform: translateY(-1px);
}
 .theme-icon {
     font-size: 1.05rem;
     transition: transform 350ms cubic-bezier(.22,1,.36,1);
}
/* ========================================================= MAIN ========================================================= */
 .main-container {
     width: min(1120px, calc(100% - 40px));
     margin: 0 auto;
}
/* ========================================================= INTRO ========================================================= */
 .intro {
     padding: 72px 0 38px;
}
 .eyebrow {
     margin: 0 0 12px;
     color: var(--accent);
     font-size: .68rem;
     font-weight: 700;
     letter-spacing: .16em;
}
 .intro h1 {
     margin: 0;
     font-size: clamp(2.5rem, 6vw, 4.5rem);
     line-height: .98;
     letter-spacing: -.065em;
}
 .intro h1 span {
     color: var(--text-muted);
}
 .intro-text {
     max-width: 540px;
     margin: 22px 0 0;
     color: var(--text-secondary);
     font-size: .98rem;
     line-height: 1.7;
}
/* ========================================================= CONTROLS ========================================================= */
 .controls {
     position: sticky;
     top: 84px;
     z-index: 30;
     padding: 10px 0 14px;
     background: linear-gradient( to bottom, var(--bg) 0%, color-mix( in srgb, var(--bg) 75%, transparent ) 75%, transparent );
}
/* ========================================================= SEARCH ========================================================= */
 .search-container {
     display: flex;
     align-items: center;
     gap: 10px;
     height: 54px;
     padding: 0 16px;
     border-radius: 18px;
     background: var(--glass-strong);
     border: 1px solid var(--border);
     backdrop-filter: blur(26px) saturate(160%);
     -webkit-backdrop-filter: blur(26px) saturate(160%);
     box-shadow: inset 0 1px 0 rgba(255,255,255,.06), 0 8px 30px var(--shadow);
     transition: border-color 180ms ease, box-shadow 180ms ease;
}
 .search-container:focus-within {
     border-color: rgba(10,132,255,.4);
     box-shadow: 0 0 0 4px rgba(10,132,255,.07), 0 12px 35px var(--shadow);
}
 .search-icon {
     color: var(--text-muted);
     font-size: 1.4rem;
}
 .search-container input {
     flex: 1;
     min-width: 0;
     border: 0;
     outline: 0;
     color: var(--text);
     background: transparent;
     font-size: .9rem;
}
 .search-container input::placeholder {
     color: var(--text-muted);
}
 .clear-search {
     width: 26px;
     height: 26px;
     display: flex;
     align-items: center;
     justify-content: center;
     border: 0;
     border-radius: 50%;
     color: var(--text-muted);
     background: transparent;
     opacity: 0;
     pointer-events: none;
     transition: opacity 160ms ease, background-color 160ms ease;
}
 .clear-search.visible {
     opacity: 1;
     pointer-events: auto;
}
 .clear-search:hover {
     background: var(--glass-hover);
     color: var(--text);
}
/* ========================================================= CATEGORY SCROLL ========================================================= */
 .category-container, .subcategory-container {
     display: flex;
     gap: 8px;
     overflow-x: auto;
     overflow-y: hidden;
     padding: 9px 2px 3px;
     scrollbar-width: none;
     -webkit-overflow-scrolling: touch;
     overscroll-behavior-x: contain;
}
 .category-container::-webkit-scrollbar, .subcategory-container::-webkit-scrollbar {
     display: none;
}
/* ========================================================= CATEGORY ========================================================= */
 .category-btn {
     flex: 0 0 auto;
     padding: 8px 14px;
     border-radius: 999px;
     border: 1px solid var(--border);
     color: var(--text-secondary);
     background: var(--glass);
     backdrop-filter: blur(16px);
     -webkit-backdrop-filter: blur(16px);
     white-space: nowrap;
     transition: background-color 180ms ease, border-color 180ms ease, color 180ms ease, transform 180ms ease;
}
 .category-btn:hover {
     color: var(--text);
     background: var(--glass-hover);
     transform: translateY(-1px);
}
 .category-btn.active {
     color: #fff;
     border-color: rgba(255,255,255,.16);
     background: linear-gradient( 135deg, rgba(10,132,255,.88), rgba(94,92,230,.84) );
     box-shadow: 0 7px 22px rgba(10,132,255,.18);
}
/* ========================================================= SUBCATEGORIES ========================================================= */
 .subcategory-container {
     padding-top: 5px;
     animation: subcategoryIn 240ms cubic-bezier(.22,1,.36,1);
}
 .subcategory-btn {
     flex: 0 0 auto;
     padding: 7px 12px;
     border-radius: 999px;
     border: 1px solid var(--border);
     background: rgba(255,255,255,.035);
     color: var(--text-muted);
     white-space: nowrap;
     transition: background-color 180ms ease, color 180ms ease, border-color 180ms ease;
}
 .subcategory-btn:hover {
     color: var(--text);
     background: var(--glass-hover);
}
 .subcategory-btn.active {
     color: var(--text);
     border-color: rgba(10,132,255,.28);
     background: rgba(10,132,255,.10);
}
 @keyframes subcategoryIn {
     from {
         opacity: 0;
         transform: translateY(-5px);
    }
     to {
         opacity: 1;
         transform: translateY(0);
    }
}
/* ========================================================= RESULTS HEADER ========================================================= */
 .results-section {
     padding: 34px 0 80px;
}
 .results-header {
     display: flex;
     align-items: flex-end;
     justify-content: space-between;
     gap: 20px;
     margin-bottom: 22px;
}
 .results-label {
     color: var(--accent);
     font-size: .65rem;
     font-weight: 700;
     letter-spacing: .14em;
}
 .results-header h2 {
     margin: 5px 0 0;
     font-size: 1.45rem;
     letter-spacing: -.03em;
}
 .results-count {
     color: var(--text-muted);
     font-size: .75rem;
}
/* ========================================================= BOOK GRID ========================================================= */
 .books-grid {
     display: grid;
     grid-template-columns: repeat(3, minmax(0, 1fr));
     gap: 16px;
}
/* ========================================================= CARD ========================================================= */
 .book-card {
     position: relative;
     display: flex;
     flex-direction: column;
     min-height: 245px;
     padding: 22px;
     border-radius: 22px;
     overflow: hidden;
     background: var(--glass);
     border: 1px solid var(--border);
     backdrop-filter: blur(22px) saturate(145%);
     -webkit-backdrop-filter: blur(22px) saturate(145%);
     box-shadow: inset 0 1px 0 rgba(255,255,255,.055), 0 10px 35px var(--shadow);
     transition: background-color 220ms ease, border-color 220ms ease, transform 260ms cubic-bezier(.22,1,.36,1), box-shadow 260ms ease;
}
 .book-card::before {
     content: "";
     position: absolute;
     inset: 0;
     pointer-events: none;
     background: radial-gradient( circle at 0% 0%, rgba(255,255,255,.08), transparent 36% );
}
 .book-card:hover {
     transform: translateY(-5px);
     background: var(--glass-hover);
     border-color: var(--border-strong);
     box-shadow: inset 0 1px 0 rgba(255,255,255,.08), 0 20px 50px var(--shadow);
}
/* ========================================================= CARD CONTENT ========================================================= */
 .card-category {
     display: inline-flex;
     width: fit-content;
     padding: 5px 9px;
     margin-bottom: 14px;
     border-radius: 999px;
     color: var(--text-muted);
     background: rgba(255,255,255,.04);
     border: 1px solid var(--border);
     font-size: .64rem;
     font-weight: 600;
     letter-spacing: .02em;
}
 .book-card h3 {
     margin: 0 0 10px;
     font-size: 1.08rem;
     line-height: 1.3;
     letter-spacing: -.025em;
}
 .book-description {
     margin: 0;
     color: var(--text-secondary);
     font-size: .82rem;
     line-height: 1.65;
}
 .card-footer {
     margin-top: auto;
     padding-top: 20px;
     display: flex;
     align-items: center;
     justify-content: space-between;
     gap: 10px;
}
/* ========================================================= ACTION ========================================================= */
 .book-action {
     display: inline-flex;
     align-items: center;
     justify-content: center;
     padding: 8px 13px;
     border-radius: 999px;
     border: 1px solid var(--border);
     color: var(--text);
     background: var(--glass-strong);
     font-size: .72rem;
     font-weight: 600;
     backdrop-filter: blur(14px);
     -webkit-backdrop-filter: blur(14px);
     transition: background-color 180ms ease, border-color 180ms ease, color 180ms ease, transform 180ms ease;
}
 .book-action:hover {
     color: #fff;
     background: var(--accent);
     border-color: rgba(255,255,255,.15);
     transform: translateY(-1px);
}
/* ========================================================= EMPTY ========================================================= */
 .empty-state {
     padding: 80px 20px;
     text-align: center;
     border-radius: 24px;
     background: var(--glass);
     border: 1px solid var(--border);
     backdrop-filter: blur(20px);
     -webkit-backdrop-filter: blur(20px);
}
 .empty-icon {
     width: 52px;
     height: 52px;
     margin: 0 auto 14px;
     display: flex;
     align-items: center;
     justify-content: center;
     border-radius: 50%;
     color: var(--text-muted);
     background: var(--glass-strong);
     border: 1px solid var(--border);
     font-size: 1.4rem;
}
 .empty-state h3 {
     margin: 0 0 6px;
}
 .empty-state p {
     margin: 0;
     color: var(--text-muted);
     font-size: .82rem;
}
/* ========================================================= FOOTER ========================================================= */
 .site-footer {
     padding: 30px 20px 40px;
     text-align: center;
     color: var(--text-muted);
     font-size: .72rem;
}
 .site-footer a {
     color: var(--text-secondary);
}
 .site-footer a:hover {
     color: var(--accent);
}
/* ========================================================= RESPONSIVE ========================================================= */
 @media (max-width: 900px) {
     .books-grid {
         grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}
 @media (max-width: 640px) {
     .site-header {
         padding: 10px 15px;
    }
     .main-container {
         width: min( 100% - 28px, 1120px );
    }
     .avatar {
         width: 36px;
         height: 36px;
    }
     .brand-name {
         font-size: .86rem;
    }
     .works-count {
         width: 58px;
         height: 58px;
    }
     .theme-toggle {
         width: 38px;
         height: 38px;
    }
     .intro {
         padding: 55px 0 28px;
    }
     .intro h1 {
         font-size: 2.6rem;
    }
     .controls {
         top: 69px;
    }
     .books-grid {
         grid-template-columns: 1fr;
    }
     .results-header {
         align-items: center;
    }
}
/* ========================================================= REDUCED MOTION ========================================================= */
 @media (prefers-reduced-motion: reduce) {
     *, *::before, *::after {
         animation-duration: .01ms !important;
         transition-duration: .01ms !important;
         scroll-behavior: auto !important;
    }
}