/* ==================== CSS Variables ==================== */
:root {
    /* Colors - Light Theme */
    --primary: #2563EB;
    --primary-light: #3B82F6;
    --primary-dark: #1E40AF;
    --surface: #FAFAFA;
    --surface-container: #F5F5F7;
    --surface-elevated: #FFFFFF;
    --on-surface: #1A1A1A;
    --on-surface-variant: #6B7280;
    --outline: #E5E5E7;
    --outline-variant: #F0F0F2;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-elevated: rgba(0, 0, 0, 0.15);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-full: 50px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Theme */
[data-theme="dark"] {
    --primary: #3B82F6;
    --primary-light: #60A5FA;
    --primary-dark: #2563EB;
    --surface: #1A1A1A;
    --surface-container: #2A2A2A;
    --surface-elevated: #2F2F2F;
    --on-surface: #F5F5F5;
    --on-surface-variant: #9CA3AF;
    --outline: #404040;
    --outline-variant: #303030;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-elevated: rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--surface);
    color: var(--on-surface);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}

/* ==================== App Container ==================== */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding-bottom: 80px;
}

/* ==================== Header ==================== */
.app-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--surface-elevated);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--outline);
    padding: var(--spacing-md) var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 8px var(--shadow);
}

.app-title {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 0.5px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    border: none;
    background: var(--surface-container);
    color: var(--on-surface);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    position: relative;
}

.theme-toggle:hover {
    background: var(--outline);
    transform: scale(1.05);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.sun-icon,
.moon-icon {
    position: absolute;
    transition: all var(--transition-base);
}

[data-theme="light"] .moon-icon,
[data-theme="dark"] .sun-icon {
    opacity: 0;
    transform: rotate(180deg) scale(0);
}

[data-theme="light"] .sun-icon,
[data-theme="dark"] .moon-icon {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

/* ==================== SEO Intro Section ==================== */
.intro-section {
    background: var(--surface-elevated);
    border-bottom: 1px solid var(--outline);
    padding: var(--spacing-xl) var(--spacing-lg);
    margin: 0;
}

.seo-title {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--on-surface);
    text-align: center;
    line-height: 1.3;
}

.intro-content {
    max-width: 900px;
    margin: 0 auto;
    color: var(--on-surface-variant);
    line-height: 1.8;
}

.intro-content p {
    margin-bottom: var(--spacing-md);
    font-size: 15px;
}

.intro-content strong {
    color: var(--on-surface);
    font-weight: 600;
}

.section-heading {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--on-surface);
    display: none;
}

/* ==================== Content ==================== */
.app-content {
    flex: 1;
    padding: var(--spacing-lg);
}

.screen {
    display: none;
    animation: fadeIn var(--transition-base);
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.screen-title {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    letter-spacing: 0.3px;
}

/* ==================== Category Tabs ==================== */
.category-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: var(--spacing-xs);
}

.category-tabs::-webkit-scrollbar {
    display: none;
}

.category-tab {
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-full);
    background: var(--surface-container);
    color: var(--on-surface-variant);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    white-space: nowrap;
    transition: all var(--transition-base);
    position: relative;
}

.category-tab:hover {
    background: var(--outline);
    transform: translateY(-2px);
}

.category-tab.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* ==================== Newspapers Grid ==================== */
.newspapers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-md);
    animation: fadeIn var(--transition-base);
}

.newspaper-card {
    background: var(--surface-elevated);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    border: 1px solid var(--outline);
    position: relative;
    overflow: hidden;
}

.newspaper-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.newspaper-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow-elevated);
    border-color: var(--primary);
}

.newspaper-card:hover::before {
    transform: scaleX(1);
}

.newspaper-card:active {
    transform: translateY(-2px);
}

.newspaper-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.newspaper-logo {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.newspaper-info {
    flex: 1;
    min-width: 0;
}

.newspaper-name {
    font-size: 16px;
    font-weight: 600;
    color: var(--on-surface);
    margin-bottom: 2px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.newspaper-bangla-name {
    font-size: 14px;
    color: var(--on-surface-variant);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.bookmark-btn {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    border: none;
    background: var(--surface-container);
    color: var(--on-surface-variant);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    flex-shrink: 0;
}

.bookmark-btn:hover {
    background: var(--outline);
    transform: scale(1.1);
}

.bookmark-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
}

.bookmark-btn svg {
    width: 18px;
    height: 18px;
}

.bookmark-btn.active svg {
    fill: white;
}

.newspaper-category {
    display: inline-block;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    background: var(--surface-container);
    color: var(--on-surface-variant);
    font-size: 12px;
    font-weight: 500;
}

/* ==================== Search ==================== */
.search-container {
    margin-bottom: var(--spacing-lg);
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--surface-elevated);
    border: 2px solid var(--outline);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: all var(--transition-base);
}

.search-box:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.search-box svg {
    color: var(--on-surface-variant);
    margin-right: var(--spacing-md);
}

.search-box input {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--on-surface);
    font-size: 16px;
    outline: none;
    font-family: inherit;
}

.search-box input::placeholder {
    color: var(--on-surface-variant);
}

/* ==================== Empty State ==================== */
.empty-state {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
    text-align: center;
    color: var(--on-surface-variant);
    min-height: 300px;
}

.empty-state.show {
    display: flex;
}

.empty-state svg {
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state p {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.empty-state span {
    font-size: 14px;
    opacity: 0.7;
}

/* ==================== Info Content ==================== */
.info-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.info-card {
    background: var(--surface-elevated);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--outline);
}

.info-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.about-text {
    color: var(--on-surface-variant);
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
}

.app-version {
    display: inline-block;
    padding: 6px 16px;
    border-radius: var(--radius-full);
    background: var(--surface-container);
    color: var(--on-surface-variant);
    font-size: 13px;
    font-weight: 500;
}

/* ==================== Bottom Navigation ==================== */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--surface-elevated);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--outline);
    display: flex;
    justify-content: space-around;
    padding: var(--spacing-sm) var(--spacing-md);
    box-shadow: 0 -2px 16px var(--shadow);
    z-index: 100;
}

.nav-item {
    flex: 1;
    max-width: 100px;
    height: 56px;
    border: none;
    background: transparent;
    color: var(--on-surface-variant);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    position: relative;
}

.nav-item::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 32px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    border-radius: 2px 2px 0 0;
    transition: transform var(--transition-base);
}

.nav-item:hover {
    background: var(--surface-container);
}

.nav-item.active {
    color: var(--primary);
}

.nav-item.active::before {
    transform: translateX(-50%) scaleX(1);
}

.nav-icon {
    transition: transform var(--transition-base);
}

.nav-item:active .nav-icon {
    transform: scale(0.9);
}

/* ==================== Responsive Design ==================== */
@media (max-width: 768px) {
    .app-content {
        padding: var(--spacing-md);
    }

    .newspapers-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: var(--spacing-md);
    }

    .category-tabs {
        gap: var(--spacing-xs);
    }

    .category-tab {
        padding: 8px 16px;
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .app-header {
        padding: var(--spacing-md);
    }

    .app-title {
        font-size: 18px;
    }

    .intro-section {
        padding: var(--spacing-lg) var(--spacing-md);
    }

    .seo-title {
        font-size: 22px;
    }

    .intro-content p {
        font-size: 14px;
    }

    .newspapers-grid {
        grid-template-columns: 1fr;
    }

    .screen-title {
        font-size: 20px;
    }
}

/* ==================== Animations ==================== */
@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}