/* ==========================================================================
   ChromeTrack - Layout CSS
   Structural elements: header, footer, navigation, grids, sections
   ========================================================================== */

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 102, 255, 0.1);
    animation: slideDown 0.6s ease-out;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px var(--spacing-md);
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-family: var(--font-primary);
    font-size: 26px;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.5px;
    text-decoration: none;
}

.logo:hover {
    color: var(--primary-dark);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--medium);
    font-weight: 500;
    transition: color var(--transition-normal);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
}

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 10px;
    cursor: pointer;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--dark);
    transition: all var(--transition-normal);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    background: var(--dark);
    color: var(--white);
    padding: var(--spacing-xl) 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-brand {
    font-family: var(--font-primary);
    font-size: 24px;
    font-weight: 800;
    color: var(--secondary);
    margin-bottom: var(--spacing-sm);
}

.footer-description {
    opacity: 0.7;
    font-size: 14px;
    line-height: 1.7;
}

.footer-column h4 {
    font-family: var(--font-primary);
    font-size: 16px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: color var(--transition-normal);
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    opacity: 0.6;
    font-size: 14px;
}

/* --------------------------------------------------------------------------
   Section Wrappers
   -------------------------------------------------------------------------- */
.section {
    padding: var(--spacing-2xl) 0;
}

.section-sm {
    padding: var(--spacing-xl) 0;
}

.section-lg {
    padding: 100px 0;
}

.section-dark {
    background: var(--dark);
    color: var(--white);
}

.section-light {
    background: var(--light);
}

.section-gradient {
    background: linear-gradient(135deg, var(--light) 0%, #E8F1FF 100%);
}

.section-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

/* --------------------------------------------------------------------------
   Grid Layouts
   -------------------------------------------------------------------------- */
.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.grid-auto {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

/* Two-column content layout (text + visual) */
.content-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
}

.content-grid.reverse {
    direction: rtl;
}

.content-grid.reverse > * {
    direction: ltr;
}

/* Stats grid */
.stat-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

/* Features grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

/* Problem cards grid */
.problem-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

/* --------------------------------------------------------------------------
   Page Content Spacing
   -------------------------------------------------------------------------- */
.page-content {
    margin-top: 80px; /* Account for fixed header */
}

.page-header {
    padding: var(--spacing-xl) 0;
    background: var(--light);
    text-align: center;
}

.page-header h1 {
    margin-bottom: var(--spacing-sm);
}

.page-header p {
    font-size: 20px;
    color: var(--medium);
    max-width: 600px;
    margin: 0 auto;
}

/* --------------------------------------------------------------------------
   Responsive Layout
   -------------------------------------------------------------------------- */
@media (max-width: 968px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--white);
        padding: var(--spacing-md);
        gap: 0;
        border-bottom: 1px solid var(--light);
        box-shadow: var(--shadow-sm);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 12px 0;
        border-bottom: 1px solid var(--light);
    }

    .nav-links a:last-child {
        border-bottom: none;
        margin-top: var(--spacing-sm);
    }

    .nav-toggle {
        display: flex;
    }

    .content-grid,
    .grid-2 {
        grid-template-columns: 1fr;
    }

    .content-grid.reverse {
        direction: ltr;
    }

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

    .problem-cards {
        grid-template-columns: 1fr;
    }

    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }

    .grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-column {
        margin-top: var(--spacing-md);
    }
}

@media (max-width: 640px) {
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

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