/* --- Core Variables & Architecture --- */
:root {
    --primary-color: #1A80F8;      /* Precise identity corporate industrial blue from logo */
    --secondary-color: #0B4BA2;    /* Dark industrial anchor blue */
    --text-main: #2B303A;          /* Charcoal clean gray text */
    --text-muted: #6B7280;         /* Secondary visual description text */
    --bg-main: #FFFFFF;
    --bg-light: #F8FAFC;           /* Ultra soft clean grey background */
    --border-color: #E2E8F0;       /* Border accent rule colors */
    --sidebar-width: 280px;
    --transition-speed: 0.25s;
}

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

html {
    scroll-behavior: smooth;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    color: var(--text-main);
    background-color: var(--bg-main);
}

/* --- Language Switching Architecture Layout Toggle --- */
body.lang-th .en { display: none !important; }
body.lang-en .th { display: none !important; }

/* --- Base Layout --- */
.text-primary { color: var(--primary-color); }
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.section-divider { border: 0; height: 1px; background: var(--border-color); margin: 60px 0; }

/* --- Mobile Header Bar --- */
.mobile-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 64px;
    background: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    display: none;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    z-index: 1000;
}
.mobile-logo-container {
    display: flex;
    align-items: center;
    gap: 10px;
}
.mobile-logo-container .logo-img {
    height: 36px;
    width: 36px;
    object-fit: contain;
}
.mobile-logo-container .brand-name {
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--secondary-color);
    letter-spacing: 0.5px;
}

/* --- Desktop Left Sidebar --- */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-light);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 40px 30px;
    z-index: 999;
    transition: transform var(--transition-speed) ease;
}
.sidebar-brand {
    text-align: center;
    margin-bottom: 50px;
}
.sidebar-logo {
    width: 90px;
    height: 90px;
    object-fit: contain;
    margin-bottom: 15px;
}
.company-title-nav {
    font-size: 1.4rem;
    color: var(--secondary-color);
    font-weight: 700;
    letter-spacing: 1px;
}
.company-subtitle-nav {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-top: 2px;
}
.nav-menu {
    flex-grow: 1;
}
.nav-menu ul {
    list-style: none;
}
.nav-menu li {
    margin-bottom: 12px;
}
.nav-link {
    display: block;
    padding: 12px 16px;
    color: var(--text-main);
    text-decoration: none;
    font-weight: 500;
    border-radius: 6px;
    transition: all var(--transition-speed) ease;
}
.nav-link:hover, .nav-link.active {
    background: var(--bg-main);
    color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
    padding-left: 22px;
}

/* Language Selection Buttons Container */
.sidebar-lang-switcher {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}
.lang-btn {
    background: none;
    border: none;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px 8px;
    transition: color var(--transition-speed);
}
.lang-btn:hover, .lang-btn.active {
    color: var(--primary-color);
}
.lang-divider {
    color: var(--border-color);
}

/* --- Main Content Block --- */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 60px 80px;
    max-width: 1400px;
}
.content-section {
    padding: 20px 0;
}
.section-title {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 35px;
    position: relative;
}
.subsection-title {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-bottom: 25px;
}

/* --- Hero Banner Section --- */
.hero-banner {
    background-size: cover;
    background-position: center;
    background-repeat: repeat;
    border-radius: 12px;
    padding: 80px 40px;
    margin-bottom: 50px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 20px rgba(0,0,0,0.02);
}
.hero-headline {
    font-size: 2.4rem;
    font-weight: 800;
    line-height: 1.3;
    max-width: 850px;
}

/* --- About Grid Content --- */
.about-text p {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-main);
    margin-bottom: 20px;
}

/* --- Features Component Cards --- */
.features-container {
    margin-top: 60px;
    background: var(--bg-light);
    padding: 50px 40px;
    border-radius: 12px;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}
.feature-card {
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    padding: 30px 25px;
    border-radius: 8px;
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
}
.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}
.feature-icon {
    font-size: 2rem;
    margin-bottom: 15px;
}
.feature-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
}

/* --- Product Interactive Tabs System --- */
.tabs-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 15px;
}
.tab-btn {
    background: none;
    border: none;
    font-size: 1.2rem;
    font-weight: 600;
    padding: 10px 30px;
    cursor: pointer;
    color: var(--text-muted);
    position: relative;
    transition: color var(--transition-speed);
}
.tab-btn:hover {
    color: var(--primary-color);
}
.tab-btn.active {
    color: var(--primary-color);
}
.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -17px;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary-color);
}
.tab-content {
    display: none;
}
.tab-content.active {
    display: block;
    animation: fadeIn var(--transition-speed) ease-in-out;
}
.product-intro p {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: 15px;
}
.product-intro ul {
    margin-left: 20px;
    margin-bottom: 20px;
    line-height: 1.7;
}

/* --- Product Galleries --- */
.product-gallery {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 40px 0;
}
.product-image-card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background: #FFF;
}
.product-image-card img {
    width: 100%;
    height: 400px;
    object-fit: cover;
    display: block;
    transition: transform 0.5s ease;
}
.product-image-card:hover img {
    transform: scale(1.02);
}
.image-caption {
    padding: 15px;
    background: var(--bg-light);
    border-top: 1px solid var(--border-color);
    text-align: center;
    font-weight: 600;
    font-size: 1rem;
}

/* --- Spec Configurations Maps & Cards --- */
.specs-wrapper {
    margin-top: 50px;
}
.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-top: 25px;
}
.spec-card {
    background: var(--bg-light);
    border-left: 4px solid var(--primary-color);
    padding: 20px;
    border-radius: 0 8px 8px 0;
}
.spec-card h5 {
    font-size: 0.85rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 0.5px;
    margin-bottom: 6px;
}
.spec-card p {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    line-height: 1.4;
}

/* --- Product Size Pillars Grid --- */
.size-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-top: 25px;
}
.size-pill {
    background: var(--bg-main);
    border: 2px solid var(--border-color);
    padding: 12px 30px;
    border-radius: 30px;
    font-weight: 700;
    color: var(--secondary-color);
    font-size: 1.1rem;
    transition: all var(--transition-speed);
}
.size-pill:hover {
    border-color: var(--primary-color);
    background: var(--bg-light);
}

/* --- Neutrally Engineered Structural Canvas Component Placeholder --- */
.placeholder-box {
    width: 100%;
    height: 200px;
    background: #F1F5F9;
    border: 2px dashed #CBD5E1;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 20px;
}

/* --- Contact Structural Grid --- */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 50px;
    margin-top: 40px;
}
.contact-info {
    display: flex;
    flex-direction: column;
    gap: 25px;
}
.company-legal-name {
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: -15px;
    color: var(--text-muted);
}
.info-item strong {
    display: block;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
    margin-bottom: 5px;
}
.info-item a {
    font-size: 1.3rem;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 700;
}
.info-item a:hover {
    text-decoration: underline;
}

/* --- Front-End Standardized Form Blocks --- */
.contact-form-wrapper {
    background: var(--bg-light);
    padding: 40px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}
.form-group {
    margin-bottom: 20px;
}
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}
.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-main);
}
.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    background: var(--bg-main);
    border-radius: 6px;
    font-size: 1rem;
    font-family: inherit;
    color: var(--text-main);
    transition: border-color var(--transition-speed);
}
.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}
.submit-btn {
    width: 100%;
    background: var(--primary-color);
    color: #FFF;
    border: none;
    padding: 14px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: background var(--transition-speed);
}
.submit-btn:hover {
    background: var(--secondary-color);
}
.form-feedback {
    margin-top: 15px;
    font-size: 0.95rem;
    font-weight: 600;
    text-align: center;
}

/* --- Footer Configuration Architecture --- */
.site-footer {
    margin-top: 100px;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
}
.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.95rem;
    flex-wrap: wrap;
    gap: 20px;
}
.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 20px;
    transition: color var(--transition-speed);
}
.footer-links a:hover {
    color: var(--primary-color);
}

/* --- CSS Structural Keyframe Animations --- */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-fade-in {
    animation: fadeIn 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* --- Comprehensive Modular Responsive Breakpoints Configuration --- */
@media (max-width: 1024px) {
    .main-content {
        padding: 40px;
    }
    .product-gallery {
        grid-template-columns: 1fr;
    }
    .product-image-card img {
        height: 320px;
    }
}

@media (max-width: 768px) {
    .mobile-header {
        display: flex;
    }
    .sidebar {
        transform: translateX(-100%);
        width: 100%;
        max-width: 300px;
        height: calc(100vh - 64px);
        top: 64px;
        padding: 30px 20px;
    }
    .sidebar.open {
        transform: translateX(0);
    }
    .sidebar-brand {
        display: none; /* Redundant on mobile viewport views */
    }
    .main-content {
        margin-left: 0;
        padding: 100px 20px 40px 20px;
    }
    .hero-banner {
        padding: 45px 20px;
    }
    .hero-headline {
        font-size: 1.6rem;
    }
    .contact-container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }
    .tabs-container {
        gap: 5px;
    }
    .tab-btn {
        padding: 10px 15px;
        font-size: 1rem;
    }
    /* Mobile Hamburger Trigger Graphics Construction */
    .hamburger {
        background: none;
        border: none;
        cursor: pointer;
        display: flex;
        flex-direction: column;
        gap: 6px;
    }
    .hamburger span {
        display: block;
        width: 26px;
        height: 3px;
        background: var(--secondary-color);
        transition: transform 0.3s, opacity 0.3s;
    }
    .hamburger.active span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
    .hamburger.active span:nth-child(2) { opacity: 0; }
    .hamburger.active span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }
}