/* ========================
   BMW-Inspired Design System
   Van Hoan Commercial LLC
   ======================== */

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

:root {
    /* Color Palette - Light Mode */
    --color-black: #000000;
    --color-white: #FFFFFF;
    --color-blue: #ccef57;
    --color-red: #E13123;
    --color-gray: #666666;
    --color-light-gray: #F2F2F2;
    --color-dark-bg: #121212;
    --color-dark-surface: #1e1e1e;
    --color-dark-text: #ffffff;
    --color-dark-text-secondary: #b3b3b3;
    --color-dark-border: #333333;

    /* Typography */
    --font-primary: 'Inter', 'Montserrat', sans-serif;
    --font-body: 'Roboto', 'Inter', sans-serif;
    --font-size-base: 16px;
    --font-size-large: 18px;

    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 64px;

    /* Transitions */
    --transition-standard: all 0.3s ease;
    --transition-fast: all 0.2s ease;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --color-black: #ffffff;
    --color-white: #121212;
    --color-gray: #cccccc;
    --color-light-gray: #1e1e1e;
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-accent: #2a2a2a;
    --border-color: #333333;
}
    --bg-primary: var(--color-dark-bg);
    --bg-secondary: var(--color-dark-surface);
    --text-primary: var(--color-dark-text);
    --text-secondary: var(--color-dark-text-secondary);
    --border-color: var(--color-dark-border);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--color-black);
    background-color: var(--color-white);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

[data-theme="dark"] body {
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

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

/* ========================
   Navigation Bar
   ======================== */

.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(20px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

[data-theme="dark"] .navbar {
    background-color: rgba(18, 18, 18, 0.95);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.logo {
    display: flex;
    align-items: center;
}

.logo-image {
    height: 50px;
    width: auto;
    filter: brightness(0.8) contrast(1.2); /* Adjust brightness for green logo on dark background */
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-weight: 600;
    position: relative;
    transition: var(--transition-fast);
    font-size: 14px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-blue);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

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

.language-select {
    background-color: transparent;
    color: var(--color-white);
    border: 1px solid var(--color-blue);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 12px;
    cursor: pointer;
    border-radius: 4px;
    transition: var(--transition-fast);
}

.language-select:hover {
    background-color: var(--color-blue);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--color-blue);
    color: var(--color-white);
    padding: var(--spacing-xs) var(--spacing-sm);
    cursor: pointer;
    border-radius: 4px;
    transition: var(--transition-fast);
    font-size: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
}

.theme-toggle:hover {
    background-color: var(--color-blue);
    transform: scale(1.05);
}

.theme-icon {
    font-size: 16px;
    transition: transform 0.3s ease;
}

.theme-toggle[data-theme="dark"] .theme-icon {
    content: "☀️";
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    background: none;
    border: none;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--color-white);
    margin: 5px 0;
    transition: var(--transition-fast);
}

/* ========================
   Hero Section
   ======================== */

.hero {
    margin-top: 70px;
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--color-black) 0%, #1a1a1a 100%);
    position: relative;
    overflow: hidden;
    transition: background 0.3s ease;
}

[data-theme="dark"] .hero {
    background: linear-gradient(135deg, #0a0a0a 0%, #1a1a1a 100%);
}

.hero-background {
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(28, 105, 210, 0.2) 0%, transparent 70%);
    border-radius: 50%;
    top: -100px;
    right: -100px;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(30px);
    }
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    max-width: 600px;
    color: var(--color-white);
    animation: slideUp 0.8s ease forwards;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title {
    font-family: var(--font-primary);
    font-size: clamp(32px, 8vw, 64px);
    font-weight: 900;
    letter-spacing: -1px;
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: clamp(16px, 4vw, 24px);
    color: var(--color-light-gray);
    margin-bottom: var(--spacing-lg);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ========================
   Buttons
   ======================== */

.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 16px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: var(--transition-standard);
    border-radius: 4px;
    font-family: var(--font-primary);
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

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

.btn-primary:hover {
    background-color: #155ab8;
    transform: scale(1.05);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-blue);
    border: 2px solid var(--color-blue);
}

.btn-secondary:hover {
    background-color: var(--color-blue);
    color: var(--color-white);
}

/* ========================
   Sections
   ======================== */

section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-family: var(--font-primary);
    font-size: clamp(28px, 6vw, 48px);
    font-weight: 900;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    letter-spacing: -0.5px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-gray);
    font-size: 16px;
    margin-bottom: var(--spacing-lg);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ========================
   Products Section
   ======================== */

#products {
    background-color: var(--color-white);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.product-card {
    background-color: var(--color-light-gray);
    padding: var(--spacing-lg);
    border-radius: 8px;
    text-align: center;
    transition: var(--transition-standard);
    border: 1px solid #e0e0e0;
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    background-color: var(--color-white);
}

.product-icon {
    font-size: 48px;
    font-weight: 900;
    margin-bottom: var(--spacing-md);
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-family: var(--font-primary);
}

.product-icon.oxygen {
    background-color: rgba(28, 105, 210, 0.1);
    color: var(--color-blue);
}

.product-icon.nitrogen {
    background-color: rgba(225, 49, 35, 0.1);
    color: var(--color-red);
}

.product-icon.argon {
    background-color: rgba(102, 102, 102, 0.1);
    color: var(--color-gray);
}

.product-icon.cylinders {
    background-color: rgba(28, 105, 210, 0.1);
}

.product-card h3 {
    font-family: var(--font-primary);
    font-size: 20px;
    margin-bottom: var(--spacing-sm);
    font-weight: 700;
}

.product-card p {
    color: var(--color-gray);
    font-size: 14px;
}

/* ========================
   Industries Section
   ======================== */

#industries {
    background-color: var(--color-light-gray);
}

.industries-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.industry-item {
    background-color: var(--color-white);
    padding: var(--spacing-lg);
    border-radius: 8px;
    text-align: center;
    border-left: 4px solid var(--color-blue);
    transition: var(--transition-standard);
}

.industry-item:hover {
    border-left-color: var(--color-red);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.industry-item h4 {
    font-family: var(--font-primary);
    font-size: 18px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.industry-item p {
    color: var(--color-gray);
    font-size: 14px;
}

/* ========================
   Services Section
   ======================== */

#services {
    background-color: var(--color-white);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.service-card {
    background: linear-gradient(135deg, var(--color-light-gray) 0%, var(--color-white) 100%);
    padding: var(--spacing-lg);
    border-radius: 8px;
    border: 1px solid #e0e0e0;
    transition: var(--transition-standard);
}

.service-card:hover {
    border-color: var(--color-blue);
    box-shadow: 0 15px 40px rgba(28, 105, 210, 0.1);
}

.service-card h3 {
    font-family: var(--font-primary);
    font-size: 20px;
    margin-bottom: var(--spacing-sm);
    color: var(--color-black);
    font-weight: 700;
}

.service-card p {
    color: var(--color-gray);
    font-size: 14px;
}

/* ========================
   Contact Section
   ======================== */

#contact {
    background-color: #f8f8f8;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.info-item h4 {
    font-family: var(--font-primary);
    font-size: 16px;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--color-black);
}

.info-item p {
    color: var(--color-gray);
    font-size: 14px;
}

.info-item a {
    color: var(--color-blue);
    text-decoration: none;
    transition: var(--transition-fast);
}

.info-item a:hover {
    color: var(--color-red);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-form input,
.contact-form textarea {
    padding: var(--spacing-sm);
    border: 1px solid #ddd;
    border-radius: 4px;
    font-family: var(--font-body);
    font-size: 14px;
    transition: var(--transition-fast);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--color-blue);
    box-shadow: 0 0 0 3px rgba(28, 105, 210, 0.1);
}

/* ========================
   Footer
   ======================== */

.footer {
    background-color: var(--color-black);
    color: var(--color-white);
    text-align: center;
    padding: var(--spacing-lg) 0;
    font-size: 14px;
}

/* ========================
   Responsive Design
   ======================== */

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        flex-direction: column;
        background-color: rgba(0, 0, 0, 0.95);
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
    }

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

    .hamburger {
        display: flex;
    }

    .logo-image {
        height: 40px;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
    }

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

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

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

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

    .section-title {
        font-size: 28px;
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-md: 16px;
        --spacing-lg: 24px;
    }

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

    .section-title {
        font-size: 24px;
        margin-bottom: var(--spacing-lg);
    }

    section {
        padding: var(--spacing-lg) 0;
    }

    .product-icon {
        font-size: 36px;
        height: 60px;
    }
}

/* ========================
   Facilities Section
   ======================== */

.facilities {
    background-color: #f9f9f9;
    transition: background-color 0.3s ease;
}

[data-theme="dark"] .facilities {
    background-color: var(--color-dark-bg);
}

.facilities-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-top: 40px;
}

.facility-card {
    padding: 30px;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    transition: var(--transition-standard);
}

[data-theme="dark"] .facility-card {
    background-color: var(--color-dark-surface);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.facility-card:hover {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    transform: translateY(-4px);
}

.facility-card h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-blue);
    margin-bottom: 20px;
}

.facility-details {
    margin-top: 20px;
}

.detail-item {
    margin-bottom: 15px;
}

.detail-item strong {
    color: var(--color-blue);
    font-weight: 600;
}

.detail-item p {
    color: var(--color-gray);
    margin-top: 5px;
    line-height: 1.6;
}

.map-container {
    margin-top: 20px;
    border-radius: 8px;
    overflow: hidden;
    height: 350px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.map-container iframe {
    border: none;
}

/* ========================
   Main Office Section
   ======================== */

.main-office {
    padding: 60px 0;
}

.office-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-top: 40px;
}

.office-info {
    padding: 30px;
    background-color: var(--color-light-gray);
    border-radius: 8px;
}

.office-info h4 {
    font-size: 18px;
    margin-bottom: 15px;
    color: var(--color-blue);
    font-weight: 700;
}

.office-map {
    border-radius: 8px;
    overflow: hidden;
    height: 300px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.office-map iframe {
    border: none;
}

/* Responsive - Facilities */
@media (max-width: 768px) {
    .facilities-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .office-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .map-container {
        height: 250px;
    }

    .office-map {
        height: 250px;
    }

    .facility-card {
        padding: 20px;
    }
}

/* ========================
   Dark Mode Enhancements
   ======================== */

[data-theme="dark"] h1,
[data-theme="dark"] h2,
[data-theme="dark"] h3,
[data-theme="dark"] h4,
[data-theme="dark"] h5,
[data-theme="dark"] h6 {
    color: var(--text-primary);
}

[data-theme="dark"] p,
[data-theme="dark"] li,
[data-theme="dark"] span {
    color: var(--text-secondary);
}

[data-theme="dark"] .section-title {
    color: var(--text-primary);
}

[data-theme="dark"] .section-subtitle {
    color: var(--text-secondary);
}

[data-theme="dark"] .product-card h3,
[data-theme="dark"] .service-card h3,
[data-theme="dark"] .industry-item h4 {
    color: var(--color-blue);
}

[data-theme="dark"] .product-card p,
[data-theme="dark"] .service-card p,
[data-theme="dark"] .industry-item p {
    color: var(--text-secondary);
}

[data-theme="dark"] .facility-card h3 {
    color: var(--color-blue);
}

[data-theme="dark"] .facility-card p,
[data-theme="dark"] .detail-item p {
    color: var(--text-secondary);
}

[data-theme="dark"] .detail-item strong {
    color: var(--color-blue);
}

[data-theme="dark"] .office-info {
    background-color: var(--bg-secondary);
}

[data-theme="dark"] .office-info h4 {
    color: var(--color-blue);
}

/* ========================
   Floating Contact Buttons
   ======================== */

.contact-buttons {
    position: fixed;
    right: 20px;
    bottom: 20px;
    z-index: 999;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.contact-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 12px 16px;
    background-color: var(--color-blue);
    color: var(--color-black);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 13px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    transition: var(--transition-standard);
    white-space: nowrap;
    border: none;
    cursor: pointer;
}

.contact-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
}

.contact-btn .contact-icon {
    font-size: 18px;
}

.contact-btn .contact-label {
    font-size: 13px;
    font-weight: 600;
}

.contact-btn.whatsapp {
    background-color: #25D366;
    color: white;
}

.contact-btn.whatsapp:hover {
    background-color: #1ea952;
}

.contact-btn.zalo {
    background-color: #0084CC;
    color: white;
}

.contact-btn.zalo:hover {
    background-color: #0066a1;
}

.contact-btn.email {
    background-color: #EA4335;
    color: white;
}

.contact-btn.email:hover {
    background-color: #c5221f;
}

[data-theme="dark"] .contact-btn {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

[data-theme="dark"] .contact-btn:hover {
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.5);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .contact-buttons {
        right: 15px;
        bottom: 15px;
        gap: 10px;
    }

    .contact-btn {
        padding: 10px 14px;
        font-size: 12px;
    }

    .contact-btn .contact-icon {
        font-size: 16px;
    }
}