/* Base Styles & Variables */
:root {
    --primary-color: #00b87c;    /* Eco Green */
    --primary-dark: #009663;
    --secondary-color: #004b91;  /* Tech Blue */
    --accent-color: #f1f7f6;
    --text-color: #333333;
    --text-light: #666666;
    --bg-light: #f9fbfb;
    --bg-dark: #111e25;
    --white: #ffffff;
    --font-family: 'Inter', sans-serif;
    --transition: all 0.3s ease;
}

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

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--secondary-color);
    font-weight: 800;
    line-height: 1.2;
}

h1 { font-size: 3.5rem; margin-bottom: 20px; color: var(--white); }
h2 { font-size: 2.5rem; margin-bottom: 20px; }
h3 { font-size: 1.5rem; margin-bottom: 15px; }

p { margin-bottom: 15px; }
.subtitle { font-size: 1.2rem; color: var(--text-light); margin-bottom: 40px; }
.highlight { color: var(--primary-color); }
.text-center { text-align: center; }
.text-white { color: var(--white); }
.text-white h2 { color: var(--white); }
.margin-top { margin-top: 30px; }

/* Layout Grid */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
.section-padding { padding: 80px 0; }
.bg-light { background-color: var(--bg-light); }
.bg-dark { background-color: var(--bg-dark); }

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
}
.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
}
.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}
.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}
.btn-secondary:hover {
    background-color: var(--white);
    color: var(--secondary-color);
    transform: translateY(-2px);
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    z-index: 1000;
    backdrop-filter: blur(5px);
}
.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}
.logo-text {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--secondary-color);
}
.nav-links {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}
.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 600;
    transition: var(--transition);
}
.nav-links a:hover { color: var(--primary-color); }
.lang-switch a {
    border: 1px solid var(--secondary-color);
    padding: 6px 14px;
    border-radius: 20px;
}
.lang-switch a:hover {
    background-color: var(--secondary-color);
    color: var(--white);
}

/* Language Toggle Utilities */
body.lang-en .zh-only { display: none !important; }
body.lang-zh .en-only { display: none !important; }

/* Hero Section */
.hero {
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    background: linear-gradient(rgba(0, 75, 145, 0.7), rgba(0, 75, 145, 0.9)), url('assets/images/hero-bg.jpg') no-repeat center center/cover;
    background-color: var(--secondary-color); /* Fallback */
    margin-top: 0;
    position: relative;
    padding-top: 80px;
}
.hero-content {
    max-width: 800px;
    color: var(--white);
    animation: fadeInUp 1s ease;
}
.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}
.hero-buttons {
    display: flex;
    gap: 20px;
}

/* About Section */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}
.about-image img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}
.facilities-list {
    list-style: none;
}
.facilities-list li {
    margin-bottom: 20px;
    padding-left: 20px;
    border-left: 3px solid var(--primary-color);
}
.facilities-list .country {
    font-weight: 800;
    color: var(--secondary-color);
    display: block;
    margin-bottom: 5px;
}

/* Network */
.network-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-top: 50px;
}
.stat-box {
    background: var(--white);
    padding: 40px 20px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: var(--transition);
}
.stat-box:hover {
    transform: translateY(-10px);
}
.highlight-box {
    background-color: var(--secondary-color);
    color: var(--white);
}
.highlight-box h3 {
    color: var(--white);
}

/* Commodities Section */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}
.card {
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: var(--transition);
}
.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}
.card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}
.card-content {
    padding: 25px;
    text-align: left;
}

/* Contact */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}
.contact-details p { margin-bottom: 10px; opacity: 0.8; }
.contact-form {
    background: var(--white);
    padding: 40px;
    border-radius: 8px;
}
.contact-form input, .contact-form textarea {
    width: 100%;
    padding: 12px;
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-family: inherit;
}
.contact-form input:focus, .contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}
.contact-form button { width: 100%; }

/* Footer */
footer {
    background-color: #0d161c;
    color: #666;
    padding: 30px 0;
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container { flex-direction: column; height: auto; padding: 15px 0; text-align: center; }
    .nav-links { flex-wrap: wrap; justify-content: center; gap: 15px; margin-top: 15px; }
    h1 { font-size: 2.5rem; }
    .hero { padding-top: 120px; text-align: center; }
    .about-grid, .network-stats, .contact-grid { grid-template-columns: 1fr; gap: 30px; }
    .hero-buttons { flex-direction: column; width: 100%; align-items: stretch; }
}
@media (max-width: 480px) {
    .nav-links { font-size: 0.9rem; gap: 10px; }
    h1 { font-size: 2rem; }
    h2 { font-size: 1.8rem; }
    .cards-grid { grid-template-columns: 1fr; }
}