/* =========================================
   1. GLOBAL VARIABLES & THEME
   ========================================= */
:root {
    /* Light Mode */
    --bg-body: #f8fafc;
    --bg-nav: rgba(255, 255, 255, 0.85);
    --bg-card: #ffffff;
    --bg-footer: #e2e8f0;
    --bg-code: #1e293b;
    
    --text-main: #334155;
    --text-header: #0f172a;
    --text-muted: #64748b;
    --text-footer: #475569;
    --text-white: #ffffff;

    --border-color: #cbd5e1;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    --shadow-nav: 0 1px 3px rgba(0,0,0,0.05);

    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --accent-red: #dc2626;

    --ad-bg: #f1f5f9;
    --ad-border: #cbd5e1;
}

[data-theme="dark"] {
    /* Dark Mode */
    --bg-body: #0f172a;
    --bg-nav: rgba(15, 23, 42, 0.85);
    --bg-card: #1e293b;
    --bg-footer: #020617;
    --bg-code: #020617;

    --text-main: #cbd5e1;
    --text-header: #f8fafc;
    --text-muted: #94a3b8;
    --text-footer: #94a3b8;
    --text-white: #ffffff;

    --border-color: #334155;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --shadow-nav: 0 1px 0 rgba(255,255,255,0.05);

    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    
    --ad-bg: #1e293b;
    --ad-border: #475569;
}

/* =========================================
   2. RESET & BASE
   ========================================= */
* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    background-color: var(--bg-body);
    color: var(--text-main);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

a { text-decoration: none; color: inherit; transition: color 0.2s; }
img { max-width: 100%; display: block; }
ul { list-style: none; padding: 0; margin: 0; }

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    width: 100%;
}

/* =========================================
   3. MODERN NAVBAR
   ========================================= */
.navbar {
    background-color: var(--bg-nav);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 0.8rem 0;
    box-shadow: var(--shadow-nav);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-header);
    letter-spacing: -0.03em;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: color 0.3s ease;
    flex-shrink: 0;
}

.brand-accent {
    color: var(--primary);
}

.nav-brand img {
    height: 32px;
    width: 32px;
    border-radius: 6px;
}

/* Search Bar */
.nav-search-wrapper {
    position: relative;
    width: 100%;
    max-width: 400px;
    margin: 0 2rem;
    display: flex;
    align-items: center;
}

.nav-search-input {
    width: 100%;
    background: var(--bg-body);
    border: 1px solid var(--border-color);
    padding: 0.6rem 1rem 0.6rem 2.5rem;
    border-radius: 2rem;
    font-size: 0.9rem;
    color: var(--text-main);
    transition: all 0.2s ease;
    font-family: inherit;
}

.nav-search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    background: var(--bg-card);
}

.search-icon {
    position: absolute;
    left: 12px;
    color: var(--text-muted);
    pointer-events: none;
    opacity: 0.7;
}

.search-shortcut {
    position: absolute;
    right: 12px;
    background: var(--border-color);
    color: var(--text-muted);
    font-size: 0.75rem;
    padding: 2px 6px;
    border-radius: 4px;
    pointer-events: none;
    font-family: monospace;
    opacity: 0.8;
}

/* Nav Links & Utils */
.nav-links { display: flex; gap: 1.5rem; align-items: center; }

.nav-link { 
    font-weight: 600; 
    color: var(--text-main); 
    font-size: 0.95rem;
    position: relative;
    white-space: nowrap;
}

.nav-link:hover { color: var(--primary); }

.nav-divider {
    width: 1px;
    height: 24px;
    background: var(--border-color);
    margin: 0 0.5rem;
}

/* Buttons */
.btn-youtube {
    background-color: var(--accent-red);
    color: white;
    padding: 0.5rem 1.2rem;
    border-radius: 2rem;
    font-size: 0.85rem;
    font-weight: 600;
    transition: all 0.2s ease;
    white-space: nowrap;
}
.btn-youtube:hover { 
    transform: translateY(-1px); 
    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.25); 
    opacity: 0.95; 
}

.theme-toggle-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 36px;
    height: 36px;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-main);
    transition: all 0.2s ease;
}
.theme-toggle-btn:hover { 
    background-color: var(--border-color); 
    transform: rotate(15deg);
}

/* =========================================
   4. MODERN FOOTER
   ========================================= */
.footer {
    background-color: var(--bg-footer);
    color: var(--text-footer);
    padding: 4rem 0 2rem;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-col h4 {
    color: var(--text-header);
    font-weight: 700;
    margin-bottom: 1.2rem;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    opacity: 0.9;
}

[data-theme="dark"] .footer-col h4 { color: var(--text-white); }

.footer-col p {
    font-size: 0.9rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    max-width: 300px;
}

/* Footer Links */
.footer-links li { margin-bottom: 0.8rem; }
.footer-links a { 
    font-size: 0.9rem; 
    color: var(--text-footer); 
    transition: color 0.2s, padding-left 0.2s;
    display: inline-block;
}
.footer-links a:hover { 
    color: var(--primary); 
    padding-left: 5px;
}

.footer-cta {
    color: var(--primary);
    font-weight: bold;
    font-size: 0.9rem;
}

/* Socials */
.footer-socials {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}
.social-link img {
    width: 24px;
    height: 24px;
    opacity: 0.7;
    transition: all 0.3s ease;
}
[data-theme="dark"] .social-link img { filter: invert(1); }

.social-link:hover img {
    opacity: 1;
    transform: translateY(-2px);
}

/* Bottom Bar */
.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    opacity: 0.8;
}

/* =========================================
   RESPONSIVE
   ========================================= */
@media (max-width: 768px) {
    .nav-content { flex-wrap: wrap; gap: 1rem; }
    .nav-search-wrapper { order: 3; margin: 0; max-width: 100%; }
    .nav-links { gap: 1rem; }
    .nav-link { display: none; }
    .nav-divider { display: none; }

    .footer-grid { grid-template-columns: 1fr; gap: 2.5rem; text-align: center; }
    .footer-col { display: flex; flex-direction: column; align-items: center; }
    .footer-bottom { flex-direction: column; gap: 1rem; text-align: center; }
}

/* =========================================
   ADSTERRA RESPONSIVE STYLES
   ========================================= */
.adsterra-wrapper {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0.1rem 0;
    overflow: hidden;
    width: 100%;
}

/* Default: Show Desktop, Hide Mobile */
.ad-desktop { display: block; }
.ad-mobile { display: none; }

/* Mobile Devices (phones & small tablets) */
@media (max-width: 768px) {
    .ad-desktop { display: none; }
    .ad-mobile { display: block; }
    
    /* Ensure ads don't overflow screen width */
    .adsterra-wrapper img, 
    .adsterra-wrapper iframe {
        max-width: 100%;
        height: auto;
    }
}

/* =========================================
   INTERNAL PRODUCT & ADVERTISEMENT GROUP
   ========================================= */
/* Wrapper for both Product and Adsterra to be sticky together */
.sidebar-sticky-group {
    position: sticky;
    top: 90px;
    max-height: calc(100vh - 110px);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-top: 2rem;
    scrollbar-width: thin;
}

.sidebar-sticky-group::-webkit-scrollbar {
    width: 4px;
}
.sidebar-sticky-group::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 4px;
}

.promo-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow);
}

.promo-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-header);
    margin-bottom: 0.5rem;
}

.promo-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 1.2rem;
    line-height: 1.5;
}

.promo-btn {
    display: inline-block;
    width: 100%;
    padding: 0.75rem;
    background-color: var(--primary);
    color: white;
    font-weight: 600;
    border-radius: 6px;
    transition: background-color 0.2s ease;
}

.promo-btn:hover {
    background-color: var(--primary-hover);
    color: white;
}