/**
 * Layout CSS - Header, Footer, Grid Layout
 * D-14: Split CSS files for organization
 */

/* ========== Header ========== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: background-color var(--transition-normal), box-shadow var(--transition-normal);
}

.header.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Logo */
.header-logo a {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-img {
    height: 40px;
    width: auto;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--dark-blue);
}

/* Navigation */
.header-nav {
    display: flex;
    align-items: center;
}

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

.nav-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-dark);
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: var(--spacing-md);
    right: var(--spacing-md);
    height: 2px;
    background-color: var(--primary-blue);
}

/* Language Switcher Container */
.language-switcher {
    margin-left: var(--spacing-lg);
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    padding: var(--spacing-sm);
    font-size: 1.5rem;
    color: var(--text-dark);
    background: none;
    border: none;
    cursor: pointer;
}

/* Header Spacer (for fixed header) */
.header-spacer {
    height: var(--header-height);
}

/* ========== Footer ========== */
.footer {
    background-color: var(--dark-blue);
    color: #fff;
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.footer-section {
    /* Each section in the grid */
}

.footer-logo {
    margin-bottom: var(--spacing-md);
}

.footer-logo-img {
    height: 36px;
    width: auto;
    filter: brightness(0) invert(1);
}

.footer-company {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.6;
}

.footer-title {
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.footer-contact li {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
}

.contact-icon {
    flex-shrink: 0;
}

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: #fff;
}

.footer-social {
    display: flex;
    gap: var(--spacing-md);
}

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: #fff;
    font-size: 0.75rem;
    transition: background-color var(--transition-fast);
}

.social-link:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    padding-top: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-copyright,
.footer-icp {
    font-size: 0.8125rem;
    color: rgba(255, 255, 255, 0.6);
    margin: 0;
}

.footer-icp a {
    color: rgba(255, 255, 255, 0.6);
}

.footer-icp a:hover {
    color: #fff;
}

/* ========== Back to Top Button ========== */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    background-color: var(--dark-blue);
    color: #fff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-fast), visibility var(--transition-fast), transform var(--transition-fast);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-3px);
    background-color: var(--primary-blue);
}

/* ========== Main Layout ========== */
main {
    min-height: calc(100vh - var(--header-height) - 300px);
}

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

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-gray);
}

/* ========== Grid Layouts ========== */
.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-lg);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

/* ========== Responsive Layout ========== */
@media (max-width: 1199px) {
    .grid-4 {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 991px) {
    .grid-4,
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (max-width: 767px) {
    /* Mobile Header */
    .menu-toggle {
        display: flex;
    }

    .header-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background-color: var(--bg-white);
        box-shadow: var(--shadow-lg);
        padding: var(--spacing-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: transform var(--transition-normal), opacity var(--transition-normal), visibility var(--transition-normal);
    }

    .header-nav.open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }

    .nav-link {
        padding: var(--spacing-md);
        border-bottom: 1px solid var(--bg-light);
    }

    .nav-link.active::after {
        display: none;
    }

    .language-switcher {
        margin-left: 0;
        margin-top: var(--spacing-md);
        padding-top: var(--spacing-md);
        border-top: 1px solid var(--bg-light);
    }

    /* Mobile Grids */
    .grid-4,
    .grid-3,
    .grid-2 {
        grid-template-columns: 1fr;
    }

    /* Mobile Footer */
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}