/* ===== Global Styles ===== */
/*
 * Background Images Required:
 * - asset/coal-mine-hero.jpg (Hero section)
 * - asset/coal-mine-activity.jpg (About section - section-alt)
 * - asset/coal-mine-operations.jpg (Company Profile section)
 * - asset/coal-mine-project.jpg (Project section)
 * 
 * All images should be high-quality and related to coal mining activities.
 * If images are not available, sections will fall back to solid color backgrounds.
 */

:root {
    --primary-black: #0a0a0a;
    --dark-grey: #1a1a1a;
    --medium-grey: #333333;
    --light-grey: #444444;
    --lighter-grey: #666666;
    --accent-orange: #ff6b35;
    --accent-orange-dark: #cc4a20;
    --accent-orange-light: #ff8c55;
    --white: #ffffff;
    --text-light: #e0e0e0;
    --text-muted: #999999;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--primary-black);
    background-image: url('asset/coal-mine-bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    color: var(--text-light);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 0.5rem 0.5rem;
    border-bottom: 1px solid rgba(255, 107, 53, 0.2);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(10, 10, 10, 0.98);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.25rem 0;
}

.nav-logo {
    height: 64px;
    width: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-link:hover {
    color: var(--accent-orange);
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-light);
    transition: all 0.3s ease;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: linear-gradient(135deg, var(--primary-black) 0%, var(--dark-grey) 100%);
    background-image: url('asset/coal-mine-hero.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 107, 53, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 107, 53, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: 1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 10, 0.75);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 2rem;
    animation: fadeInUp 1s ease;
}

.hero-logo {
    width: 450px;
    max-width: 100%;
    height: auto;
    margin-bottom: 2rem;
    filter: drop-shadow(0 4px 20px rgba(255, 107, 53, 0.3));
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.5rem);
    color: var(--text-light);
    margin-bottom: 0.5rem;
    font-weight: 400;
}

.hero-location {
    font-size: clamp(0.9rem, 1.5vw, 1.1rem);
    color: var(--accent-orange);
    margin-bottom: 2rem;
    font-weight: 500;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: transparent;
    border: 2px solid var(--accent-orange);
    color: var(--accent-orange);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.cta-button:hover {
    background: var(--accent-orange);
    color: var(--primary-black);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(255, 107, 53, 0.4);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-arrow {
    width: 30px;
    height: 30px;
    border-right: 2px solid var(--accent-orange);
    border-bottom: 2px solid var(--accent-orange);
    transform: rotate(45deg);
    animation: bounce 2s infinite;
}

/* ===== Section Styles ===== */
.section {
    padding: 6rem 0;
    position: relative;
}

.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 10, 0.85);
    z-index: 0;
}

.section > .container {
    position: relative;
    z-index: 1;
}

.section-alt {
    background: var(--dark-grey);
    background-image: url('asset/coal-mine-activity.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

.section-alt::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(26, 26, 26, 0.85);
    z-index: 0;
}

/* Company Profile Section Background */
#company-profile.section {
    background-image: url('asset/coal-mine-operations.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--white);
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.section-divider {
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, transparent, var(--accent-orange), transparent);
    margin: 0 auto;
}

/* ===== Company Profile Section ===== */
.profile-content {
    display: grid;
    gap: 3rem;
}

.profile-text {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.profile-text h3 {
    font-size: 2rem;
    color: var(--accent-orange);
    margin-bottom: 1.5rem;
}

.profile-text .lead {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 1rem;
    font-weight: 500;
}

.profile-text p {
    color: var(--text-muted);
    font-size: 1.1rem;
    line-height: 1.8;
}

.profile-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.stat-card {
    background: var(--dark-grey);
    padding: 2rem;
    text-align: center;
    border: 1px solid rgba(255, 107, 53, 0.2);
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-orange);
    box-shadow: 0 10px 30px rgba(255, 107, 53, 0.2);
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent-orange);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.95rem;
    color: var(--text-light);
    line-height: 1.4;
}

/* ===== About Section ===== */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.about-card {
    background: var(--primary-black);
    padding: 2.5rem 2rem;
    border: 1px solid rgba(255, 107, 53, 0.2);
    transition: all 0.3s ease;
}

.about-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-orange);
    box-shadow: 0 10px 30px rgba(255, 107, 53, 0.2);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.about-card h3 {
    font-size: 1.5rem;
    color: var(--accent-orange);
    margin-bottom: 1rem;
}

.about-card p {
    color: var(--text-muted);
    line-height: 1.8;
}

.coal-specs {
    background: var(--primary-black);
    padding: 3rem;
    border: 1px solid rgba(255, 107, 53, 0.2);
}

.coal-specs h3 {
    font-size: 2rem;
    color: var(--white);
    margin-bottom: 2rem;
    text-align: center;
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.spec-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.spec-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.spec-value {
    font-size: 1.2rem;
    color: var(--accent-orange);
    font-weight: 600;
}

/* ===== Operations Image Gallery (About Section) ===== */
.operations-gallery {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.6fr);
    gap: 2.5rem;
    align-items: center;
    margin-bottom: 4rem;
}

.operations-text h3 {
    font-size: 2rem;
    color: var(--white);
    margin-bottom: 1rem;
}

.operations-text p {
    color: var(--text-muted);
    line-height: 1.8;
}

.operations-gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
}

.operations-image-card {
    position: relative;
    overflow: hidden;
    border-radius: 10px;
    border: 1px solid rgba(255, 107, 53, 0.25);
    background: rgba(0, 0, 0, 0.4);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.6);
    transition: transform 0.4s ease, box-shadow 0.4s ease, border-color 0.3s ease;
}

.operations-image-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    display: block;
    transition: transform 0.6s ease;
}

.operations-image-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.75), transparent 55%);
    opacity: 1;
    pointer-events: none;
}

.operations-image-card figcaption {
    position: absolute;
    left: 1rem;
    right: 1rem;
    bottom: 1rem;
    font-size: 0.85rem;
    color: var(--text-light);
    line-height: 1.4;
    z-index: 1;
}

.operations-image-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-orange);
    box-shadow: 0 20px 50px rgba(255, 107, 53, 0.35);
}

.operations-image-card:hover img {
    transform: scale(1.08);
}

/* ===== Project Section ===== */
#project.section {
    background-image: url('asset/coal-mine-project.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

.project-intro {
    text-align: center;
    max-width: 900px;
    margin: 0 auto 4rem;
}

.project-intro .lead {
    font-size: 1.25rem;
    color: var(--text-light);
    line-height: 1.8;
}

.project-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.detail-card {
    background: var(--dark-grey);
    padding: 2.5rem;
    border: 1px solid rgba(255, 107, 53, 0.2);
}

.detail-card h3 {
    font-size: 1.5rem;
    color: var(--accent-orange);
    margin-bottom: 1.5rem;
}

.detail-card p {
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    line-height: 1.8;
}

.detail-card strong {
    color: var(--text-light);
}

.advantages-list {
    list-style: none;
    padding: 0;
}

.advantages-list li {
    color: var(--text-muted);
    padding: 0.75rem 0;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.6;
}

.advantages-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-orange);
    font-weight: bold;
}

.permits-section {
    background: var(--dark-grey);
    padding: 3rem;
    border: 1px solid rgba(255, 107, 53, 0.2);
}

.permits-section h3 {
    font-size: 2rem;
    color: var(--white);
    margin-bottom: 2rem;
    text-align: center;
}

.permits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.permit-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text-muted);
    padding: 1rem;
    background: var(--primary-black);
    border-left: 3px solid var(--accent-orange);
}

.permit-status {
    color: var(--accent-orange);
    font-weight: bold;
    font-size: 1.2rem;
}

/* ===== Contact Section ===== */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-simple {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.contact-item {
    text-align: center;
    padding: 2rem;
    background: var(--primary-black);
    border: 1px solid rgba(255, 107, 53, 0.2);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.contact-item:hover {
    border-color: var(--accent-orange);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(255, 107, 53, 0.2);
}

.contact-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.75rem;
    font-weight: 500;
}

.contact-value {
    display: block;
    font-size: 1.1rem;
    color: var(--accent-orange);
    text-decoration: none;
    line-height: 1.6;
    transition: color 0.3s ease;
}

.contact-value:hover {
    color: var(--accent-orange-light);
}

.contact-item p.contact-value {
    color: var(--text-light);
    margin: 0;
}

/* ===== Footer ===== */
.footer {
    background: var(--primary-black);
    border-top: 1px solid rgba(255, 107, 53, 0.2);
    padding: 3rem 0;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr 1fr;
    gap: 2rem;
    align-items: center;
}

.footer-logo-img {
    width: 200px;
    height: auto;
}

.footer-text {
    text-align: center;
}

.footer-text p {
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.footer-tagline {
    color: var(--lighter-grey);
    font-size: 0.9rem;
}

.footer-nav {
    display: flex;
    justify-content: flex-end;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.footer-nav a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-nav a:hover {
    color: var(--accent-orange);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0) rotate(45deg);
    }
    40% {
        transform: translateX(-50%) translateY(-10px) rotate(45deg);
    }
    60% {
        transform: translateX(-50%) translateY(-5px) rotate(45deg);
    }
}

/* ===== Responsive Design ===== */
/* Change background-attachment to scroll for better mobile performance */
@media (max-width: 968px) {
    .hero,
    .section-alt,
    #project.section,
    #company-profile.section {
        background-attachment: scroll;
    }
}

@media (max-width: 968px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--primary-black);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        padding: 2rem 0;
        border-top: 1px solid rgba(255, 107, 53, 0.2);
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

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

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

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .contact-simple {
        gap: 2rem;
    }
    
    .contact-item {
        padding: 1.5rem;
    }

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

    .footer-nav {
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .section {
        padding: 4rem 0;
    }

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

    .operations-gallery {
        grid-template-columns: 1fr;
    }

    .operations-gallery-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .project-details {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 480px) {
    .hero-logo {
        width: 300px;
    }

    .profile-stats {
        grid-template-columns: 1fr;
    }

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

    .operations-gallery-grid {
        grid-template-columns: 1fr;
    }
}