/* ============================================
   Book PDF Downloader - Premium Dark Theme
   ============================================ */

:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-card: rgba(20, 20, 35, 0.7);
    --bg-card-hover: rgba(30, 30, 50, 0.8);
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-border-hover: rgba(255, 255, 255, 0.15);

    --text-primary: #f0f0f5;
    --text-secondary: #8888a0;
    --text-muted: #55556a;

    --accent-1: #6c5ce7;
    --accent-2: #a29bfe;
    --accent-3: #00cec9;
    --accent-gradient: linear-gradient(135deg, #6c5ce7, #a29bfe, #00cec9);
    --accent-glow: rgba(108, 92, 231, 0.3);

    --success: #00b894;
    --warning: #fdcb6e;
    --error: #e17055;

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(108, 92, 231, 0.15);

    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---- Reset & Base ---- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* ---- Animated Background ---- */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.bg-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
    animation: float 20s ease-in-out infinite;
}

.bg-orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-1), transparent 70%);
    top: -100px;
    right: -100px;
    animation-delay: 0s;
}

.bg-orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--accent-3), transparent 70%);
    bottom: -50px;
    left: -50px;
    animation-delay: -7s;
}

.bg-orb-3 {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--accent-2), transparent 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(30px, -40px) scale(1.05); }
    50% { transform: translate(-20px, 20px) scale(0.95); }
    75% { transform: translate(15px, 30px) scale(1.02); }
}

/* ---- App Container ---- */
.app-container {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: 40px 24px 80px;
}

/* ---- Glass Effect ---- */
.glass {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

/* ---- Header ---- */
.header {
    text-align: center;
    margin-bottom: 48px;
    animation: fadeInDown 0.6s ease-out;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 14px;
    margin-bottom: 12px;
}

.logo-icon {
    font-size: 2.5rem;
    animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.header h1 {
    font-size: 2.2rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.05rem;
    font-weight: 300;
    margin-top: 4px;
}

/* ---- Search Section ---- */
.search-section {
    margin-bottom: 40px;
    animation: fadeInUp 0.6s ease-out 0.1s both;
}

.search-card {
    padding: 28px 28px 20px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    transition: var(--transition);
}

.search-card:hover {
    border-color: var(--glass-border-hover);
}

/* Search Type Toggle */
.search-type-toggle {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
}

.toggle-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.toggle-btn:hover {
    border-color: var(--accent-2);
    color: var(--accent-2);
}

.toggle-btn.active {
    background: rgba(108, 92, 231, 0.15);
    border-color: var(--accent-1);
    color: var(--accent-2);
}

/* Search Input */
.search-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    gap: 12px;
}

.search-icon {
    position: absolute;
    left: 16px;
    color: var(--text-muted);
    pointer-events: none;
}

.search-input {
    flex: 1;
    padding: 14px 14px 14px 48px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    background: rgba(0, 0, 0, 0.3);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-input:focus {
    border-color: var(--accent-1);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.search-btn {
    padding: 14px 28px;
    border: none;
    border-radius: var(--radius-lg);
    background: var(--accent-gradient);
    color: white;
    font-family: var(--font-main);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

.search-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px var(--accent-glow);
}

.search-btn:active {
    transform: translateY(0);
}

.search-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-loader {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    margin: 0 auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Search Hints */
.search-hints {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 14px;
    flex-wrap: wrap;
}

.hint {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.hint-tag {
    padding: 4px 12px;
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 0.78rem;
    cursor: pointer;
    transition: var(--transition);
}

.hint-tag:hover {
    border-color: var(--accent-2);
    color: var(--accent-2);
    background: rgba(108, 92, 231, 0.1);
}

/* ---- Results Section ---- */
.results-section {
    animation: fadeInUp 0.4s ease-out;
}

.results-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 16px;
    flex-wrap: wrap;
    gap: 8px;
}

.results-header h2 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
}

.results-count {
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 500;
}

.results-filters {
    margin-bottom: 20px;
}

.filter-select {
    padding: 8px 14px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    background: rgba(0, 0, 0, 0.3);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.85rem;
    outline: none;
    cursor: pointer;
    transition: var(--transition);
}

.filter-select:focus {
    border-color: var(--accent-1);
}

.filter-select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

/* Results Grid */
.results-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* Book Card */
.book-card {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 16px;
    padding: 20px 24px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    animation: fadeInUp 0.3s ease-out both;
}

.book-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--glass-border-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.book-info {
    display: flex;
    flex-direction: column;
    gap: 6px;
    min-width: 0;
}

.book-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.4;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.book-author {
    font-size: 0.88rem;
    color: var(--accent-2);
    font-weight: 500;
}

.book-meta {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 4px;
}

.meta-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-secondary);
}

.meta-tag.format {
    text-transform: uppercase;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.meta-tag.format-pdf {
    background: rgba(231, 76, 60, 0.15);
    color: #e74c3c;
}

.meta-tag.format-epub {
    background: rgba(46, 204, 113, 0.15);
    color: #2ecc71;
}

.meta-tag.format-djvu {
    background: rgba(52, 152, 219, 0.15);
    color: #3498db;
}

.meta-tag.format-mobi {
    background: rgba(241, 196, 15, 0.15);
    color: #f1c40f;
}

.book-actions {
    display: flex;
    align-items: center;
}

.download-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: 1px solid var(--accent-1);
    border-radius: var(--radius-md);
    background: rgba(108, 92, 231, 0.1);
    color: var(--accent-2);
    font-family: var(--font-main);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.download-btn:hover {
    background: var(--accent-1);
    color: white;
    box-shadow: 0 0 20px var(--accent-glow);
}

.download-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.download-btn.downloading {
    background: rgba(0, 206, 201, 0.15);
    border-color: var(--accent-3);
    color: var(--accent-3);
}

.download-btn.downloaded {
    background: rgba(0, 184, 148, 0.15);
    border-color: var(--success);
    color: var(--success);
}

/* ---- Downloads Section ---- */
.downloads-section {
    margin-top: 48px;
    animation: fadeInUp 0.4s ease-out;
}

.section-header {
    margin-bottom: 16px;
}

.section-header h2 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.downloads-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.download-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 20px;
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.download-item:hover {
    border-color: var(--glass-border-hover);
}

.download-item-info {
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 0;
}

.download-item-icon {
    font-size: 1.3rem;
    flex-shrink: 0;
}

.download-item-name {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.download-item-size {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.download-item-action {
    padding: 6px 14px;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
}

.download-item-action:hover {
    border-color: var(--accent-3);
    color: var(--accent-3);
}

/* ---- Toast Notifications ---- */
.toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-lg);
    animation: slideInRight 0.3s ease-out, fadeOut 0.3s ease-in 3.7s forwards;
    max-width: 380px;
    font-size: 0.88rem;
}

.toast.success { border-left: 3px solid var(--success); }
.toast.error { border-left: 3px solid var(--error); }
.toast.info { border-left: 3px solid var(--accent-2); }

.toast-icon { font-size: 1.1rem; flex-shrink: 0; }
.toast-message { color: var(--text-primary); }

/* ---- Empty State ---- */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state-icon {
    font-size: 3rem;
    margin-bottom: 16px;
    opacity: 0.5;
}

.empty-state-text {
    font-size: 1rem;
    font-weight: 500;
}

/* ---- Loading Skeleton ---- */
.skeleton {
    background: linear-gradient(90deg,
        var(--bg-card) 25%,
        rgba(255,255,255,0.05) 50%,
        var(--bg-card) 75%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: var(--radius-md);
}

@keyframes shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-card {
    height: 80px;
    border-radius: var(--radius-lg);
}

/* ---- Animations ---- */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(60px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: translateY(10px);
    }
}

/* ---- Responsive ---- */
@media (max-width: 640px) {
    .app-container {
        padding: 24px 16px;
    }

    .header h1 {
        font-size: 1.6rem;
    }

    .search-card {
        padding: 20px 16px 16px;
    }

    .search-input-wrapper {
        flex-direction: column;
    }

    .search-btn {
        width: 100%;
        padding: 12px;
    }

    .book-card {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 16px;
    }

    .book-actions {
        justify-content: flex-start;
    }

    .download-btn {
        width: 100%;
        justify-content: center;
    }

    .results-header {
        flex-direction: column;
    }

    .download-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.2);
}