:root {
    --bg-main: #F4F4F4;
    --bg-sidebar: #FFFFFF;
    --text-main: #333333;
    --text-light: #666666;
    --accent: #111111;
    --border: #DDDDDD;
    --shadow: rgba(0, 0, 0, 0.05);
    --glow: rgba(0, 0, 0, 0.15);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Grain texture */
.background-grain {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.04;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.65' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)'/%3E%3C/svg%3E");
}

/* Parallax Background */
.parallax-bg {
    position: fixed;
    top: -50px;
    left: 0;
    width: 100%;
    height: 120vh;
    background: linear-gradient(135deg, #fdfdfd 0%, #eaeaea 100%);
    z-index: -1;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* Global Header */
.global-topbar {
    display: flex;
    background: var(--bg-sidebar);
    padding: 1rem 2rem;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.global-topbar .header-logo .logo-image {
    height: 30px;
    width: auto;
}
.top-nav {
    display: flex;
    gap: 2rem;
    align-items: center;
}
.top-nav .nav-link {
    text-decoration: none;
    color: var(--text-light);
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}
.top-nav .nav-link:hover, .top-nav .nav-link.active-link {
    color: var(--accent);
}
.hamburger-global-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-main);
}
.hamburger-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-main);
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    padding: 2rem 0;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    transition: transform 0.3s ease;
    z-index: 90;
}

.sidebar-header {
    padding: 0 2rem 2rem;
}

.logo-image-large {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

.nav-menu {
    display: flex;
    flex-direction: column;
}

.nav-item {
    padding: 1rem 2rem;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-light);
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.nav-item:hover, .nav-item.active {
    background: var(--bg-main);
    color: var(--accent);
    border-left-color: var(--accent);
}

/* Main Content */
.main-content {
    padding: 3rem 2rem;
    flex: 1;
    max-width: 1300px;
    margin: 0 auto;
}

/* 2-Column Desktop Grid */
.page-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 3rem;
    align-items: start;
}
.sticky-sidebar {
    position: sticky;
    top: 100px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.single-page-content {
    margin: 4rem auto;
    padding: 2rem;
    max-width: 800px;
    background: var(--bg-sidebar);
    border-radius: 12px;
    box-shadow: 0 4px 6px var(--shadow);
}
.single-page-content h1 {
    font-size: 2.2rem;
    color: var(--accent);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border);
}
.single-page-content h2 {
    font-size: 1.5rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-main);
}
.single-page-content p {
    margin-bottom: 1.2rem;
    line-height: 1.8;
}

.section-header {
    margin-bottom: 3rem;
    transition: transform 0.1s linear;
}

.section-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -1px;
}

/* Cards */
.calc-card {
    background: var(--bg-sidebar);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px var(--shadow);
    margin-bottom: 2rem;
    display: none;
}
.calc-card.active-calc {
    display: block;
    animation: fadeIn 0.4s ease forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.calc-card h2 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.input-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.input-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-light);
}

.input-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.2s ease;
    background: var(--bg-main);
}
.input-group input:focus {
    outline: none;
    border-color: var(--text-main);
}

.btn-calculate {
    background: var(--accent);
    color: #fff;
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.2s ease;
    box-shadow: 0 4px 6px var(--shadow);
}

.btn-calculate:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.2), 0 0 10px rgba(0,0,0,0.1);
}

.btn-calculate:active {
    transform: translateY(0) scale(0.98);
}

/* Results */
.result-card {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #FAFAFA;
    border: 2px solid var(--accent);
    border-radius: 8px;
    font-family: 'Roboto Mono', monospace, sans-serif;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
}
.result-card.hidden {
    display: none;
}

/* SEO Info Section */
.info-section-card {
    background: var(--bg-sidebar);
    padding: 3rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px var(--shadow);
    margin-top: 4rem;
    color: var(--text-light);
}
.info-section-card h2 {
    color: var(--accent);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}
.info-section-card h3 {
    color: var(--text-main);
    margin-top: 2rem;
    margin-bottom: 0.8rem;
    font-size: 1.3rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
}
.info-section-card ul, .info-section-card ol {
    margin-bottom: 1.5rem;
    padding-left: 2rem;
    color: var(--text-light);
}
.info-section-card li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}
.info-text-content p {
    margin-bottom: 1rem;
    line-height: 1.8;
}

/* Affiliates */
.affiliates-section {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.affiliate-card {
    background: var(--bg-sidebar);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px var(--shadow);
    font-size: 0.9rem;
    color: var(--text-light);
    border: 1px solid var(--border);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.affiliate-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 12px var(--shadow);
}
.affiliate-card strong {
    color: var(--text-main);
    display: block;
    margin-bottom: 0.5rem;
}

.action-row {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Footer & Visitor Counter */
.site-footer {
    margin-top: 4rem;
    padding: 3rem 2rem;
    border-top: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
}
.footer-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}
.footer-links a {
    text-decoration: none;
    color: var(--text-light);
    font-weight: 600;
    transition: color 0.2s ease;
}
.footer-links a:hover {
    color: var(--accent);
}
.footer-copy {
    color: var(--text-light);
    font-size: 0.9rem;
}

.visitor-counter {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg-sidebar);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow);
    font-weight: 600;
    color: var(--text-light);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.visitor-counter:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow);
}

.visitor-counter span {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.visitor-counter img {
    height: 20px;
    border-radius: 4px;
}

/* Responsive */
@media (max-width: 768px) {
    .action-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    .sidebar {
        transform: translateX(-100%);
        padding-top: 1rem;
    }
    .sidebar.open {
        transform: translateX(0);
        box-shadow: 10px 0 30px rgba(0,0,0,0.1);
    }
    .main-content {
        padding: 2rem;
    }
    .page-grid {
        grid-template-columns: 1fr;
    }
    .sticky-sidebar {
        position: static;
        margin-top: 3rem;
        padding-top: 2rem;
        border-top: 1px solid var(--border);
    }
    .desktop-only {
        display: none;
    }
    .global-topbar {
        padding: 1rem 2rem;
    }
    .top-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--bg-sidebar);
        flex-direction: column;
        padding: 1rem 2rem;
        border-bottom: 1px solid var(--border);
        box-shadow: 0 4px 6px var(--shadow);
    }
    .top-nav.open {
        display: flex;
    }
    .hamburger-global-btn {
        display: block;
    }
    /* Provide extra margin to footer items on mobile */
    .footer-links {
        gap: 1rem;
    }
}