/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #dc2626;
    --secondary-color: #991b1b;
    --accent-color: #f59e0b;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-light: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo h2 {
    color: var(--primary-color);
    font-size: 1.8rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i {
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

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

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-links a.active {
    color: var(--primary-color);
}

.nav-links a.active::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #dc2626 0%, #991b1b 50%, #f59e0b 100%);
    position: relative;
    text-align: center;
    color: white;
    padding-top: 80px;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 10px,
            rgba(255, 255, 255, 0.03) 10px,
            rgba(255, 255, 255, 0.03) 20px
        );
}

.hero-content {
    z-index: 1;
}

.hero-title {
    font-size: 4rem;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    animation: fadeInUp 1s ease 0.4s both;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    background-color: #f97316;
}

.scroll-down {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    font-size: 2rem;
    cursor: pointer;
    z-index: 1;
}

/* About Section */
.about {
    padding: 100px 0;
    background-color: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--primary-color);
}

.section-subtitle {
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 3rem;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: center;
}

.about-image .image-placeholder {
    width: 250px;
    height: 250px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    color: white;
    box-shadow: var(--shadow-lg);
}

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

.about-text p {
    margin-bottom: 1rem;
    color: var(--text-light);
    line-height: 1.8;
}

.skills {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.skill-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 1.5rem;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.skill-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.skill-item i {
    font-size: 2.5rem;
    color: var(--primary-color);
}

.skill-item span {
    font-weight: 600;
    color: var(--text-color);
    text-align: center;
}

/* Welding Types Section */
.welding-types {
    padding: 100px 0;
    background-color: white;
}

.welding-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.welding-card {
    background-color: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 2px solid var(--border-color);
    position: relative;
}

.welding-card.featured {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(220, 38, 38, 0.05) 0%, rgba(245, 158, 11, 0.05) 100%);
}

.featured-badge {
    position: absolute;
    top: -12px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.welding-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.welding-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: white;
    margin: 0 auto 1.5rem;
}

.welding-card h3 {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    text-align: center;
}

.welding-card p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.feature-list {
    list-style: none;
    margin-bottom: 1.5rem;
}

.feature-list li {
    padding: 0.5rem 0;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.feature-list i {
    color: var(--primary-color);
    font-size: 0.85rem;
}

.welding-params {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.param {
    background-color: var(--bg-light);
    padding: 0.5rem 1rem;
    border-radius: 5px;
    font-size: 0.9rem;
    color: var(--text-color);
    font-weight: 500;
}

/* Machining Section */
.machining {
    padding: 100px 0;
    background-color: var(--bg-light);
}

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

.machining-card {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.machining-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.machining-image {
    height: 180px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 5rem;
    color: white;
}

.machining-content {
    padding: 1.5rem;
}

.machining-content h3 {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.machining-content p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.machining-features {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.75rem;
}

.machining-features span {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-color);
    font-size: 0.9rem;
}

.machining-features i {
    color: var(--primary-color);
    font-size: 0.85rem;
}

/* Projects Section */
.projects {
    padding: 100px 0;
}

.filter-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 25px;
    border: 2px solid var(--primary-color);
    background-color: white;
    color: var(--primary-color);
    border-radius: 50px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background-color: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    opacity: 1;
}

.project-card.hide {
    display: none;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.project-image {
    height: 200px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
}

.project-content {
    padding: 1.5rem;
}

.project-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.project-content p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    padding: 5px 12px;
    background-color: var(--bg-light);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* Theory Section */
.theory {
    padding: 100px 0;
    background-color: var(--bg-light);
}

.theory-content {
    display: flex;
    flex-direction: column;
    gap: 3rem;
}

.theory-category {
    background-color: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: var(--shadow);
}

.theory-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--border-color);
}

.theory-header i {
    font-size: 2.5rem;
    color: var(--primary-color);
}

.theory-header h3 {
    font-size: 2rem;
    color: var(--text-color);
}

.theory-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.theory-item {
    background-color: var(--bg-light);
    padding: 1.5rem;
    border-radius: 10px;
    border-left: 4px solid var(--primary-color);
}

.theory-item h4 {
    font-size: 1.2rem;
    color: var(--text-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theory-item h4 i {
    color: var(--primary-color);
}

.theory-item ul {
    list-style: none;
    padding-left: 0;
}

.theory-item ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    line-height: 1.6;
    padding-left: 1.5rem;
    position: relative;
}

.theory-item ul li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.theory-item strong {
    color: var(--text-color);
}

/* Contact Section */
.contact {
    padding: 100px 0;
    background-color: white;
}

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

.contact-content > p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    align-items: center;
    margin-bottom: 3rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text-color);
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

.contact-item:hover {
    color: var(--primary-color);
}

.contact-item i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-link {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    font-size: 1.5rem;
    transition: all 0.3s ease;
}

.social-link:hover {
    transform: translateY(-5px);
    background-color: var(--secondary-color);
}

.resources {
    margin-top: 3rem;
    padding: 2rem;
    background-color: var(--bg-light);
    border-radius: 15px;
}

.resources h3 {
    font-size: 1.8rem;
    color: var(--text-color);
    margin-bottom: 1.5rem;
}

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

.resource-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background-color: white;
    border-radius: 10px;
    text-decoration: none;
    color: var(--text-color);
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.resource-link:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
    color: var(--primary-color);
}

.resource-link i {
    color: var(--primary-color);
    font-size: 1.5rem;
}

/* Footer */
.footer {
    background-color: var(--text-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

.footer-links-bar {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
    padding: 1.5rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    margin-bottom: 1.5rem;
}

.footer-links-bar a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 5px;
}

.footer-links-bar a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--accent-color);
    transform: translateY(-2px);
}

.footer-note {
    margin-top: 1rem;
    font-size: 0.9rem;
    opacity: 0.8;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.footer-note i {
    color: var(--accent-color);
}

/* 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);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* Page Header */
.page-header {
    padding: 120px 0 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.page-header p {
    font-size: 1.3rem;
    opacity: 0.9;
}

/* Mission Section */
.mission {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.mission-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.mission-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.mission-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.mission-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.mission-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.mission-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Experience Section */
.experience {
    padding: 80px 0;
}

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

.experience-item {
    text-align: center;
    padding: 2rem;
    background: var(--bg-light);
    border-radius: 10px;
}

.experience-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.experience-item h4 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.experience-item p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Equipment Section */
.equipment {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.equipment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.equipment-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.equipment-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.equipment-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.equipment-card ul {
    list-style: none;
}

.equipment-card ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    border-bottom: 1px solid var(--border-color);
}

.equipment-card ul li:last-child {
    border-bottom: none;
}

.equipment-card ul li::before {
    content: '✓ ';
    color: var(--primary-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

/* Comparison Section */
.comparison {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.comparison-table {
    margin-top: 3rem;
    overflow-x: auto;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    box-shadow: var(--shadow);
    border-radius: 10px;
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

.comparison-table tr:last-child td {
    border-bottom: none;
}

.comparison-table tr:hover {
    background-color: var(--bg-light);
}

/* Tips Section */
.tips {
    padding: 80px 0;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tip-card {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.tip-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.tip-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.tip-card ul {
    list-style: none;
}

.tip-card ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    padding-left: 1.5rem;
    position: relative;
}

.tip-card ul li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Detailed Machining Section */
.detailed-machining {
    padding: 80px 0;
}

.detail-section {
    margin-bottom: 3rem;
    background: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.detail-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 1.5rem 2rem;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.detail-header i {
    font-size: 2rem;
}

.detail-header h3 {
    margin: 0;
}

.detail-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    padding: 2rem;
}

.detail-text h4 {
    color: var(--text-color);
    margin: 1.5rem 0 1rem;
}

.detail-text ul {
    list-style: none;
}

.detail-text ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    line-height: 1.6;
}

.detail-specs h4 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.detail-specs table {
    width: 100%;
    border-collapse: collapse;
}

.detail-specs table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.detail-specs table td:first-child {
    font-weight: 600;
    color: var(--text-color);
}

.detail-specs table td:last-child {
    color: var(--text-light);
    text-align: right;
}

/* Applications Section */
.applications {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.applications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.application-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s ease;
}

.application-card:hover {
    transform: translateY(-5px);
}

.application-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.application-card h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.application-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Quality Section */
.quality {
    padding: 80px 0;
}

.quality-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.quality-item {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.quality-item i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.quality-item h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
}

.quality-item p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Stats Section */
.stats {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

.stats .section-title {
    color: white;
}

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

.stat-item {
    text-align: center;
    padding: 2rem;
}

.stat-number {
    font-size: 3.5rem;
    font-weight: bold;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Project Details */
.project-details {
    margin: 1rem 0;
    padding: 1rem;
    background: var(--bg-light);
    border-radius: 5px;
    font-size: 0.9rem;
}

.project-details p {
    margin: 0.5rem 0;
    color: var(--text-light);
}

.intro-text {
    max-width: 900px;
    margin: 0 auto 3rem;
    text-align: center;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
}

/* CTA Section */
.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .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);
    }

    .nav-links {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

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

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .about-image .image-placeholder {
        margin: 0 auto;
    }

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

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

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

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

    .theory-items {
        grid-template-columns: 1fr;
    }

    .resource-links {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 2rem;
    }

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

    .filter-buttons {
        gap: 0.5rem;
    }

    .filter-btn {
        padding: 8px 15px;
        font-size: 0.9rem;
    }

    .page-header h1 {
        font-size: 2rem;
    }

    .page-header p {
        font-size: 1rem;
    }

    .mission-grid,
    .experience-content,
    .equipment-grid,
    .tips-grid,
    .applications-grid,
    .quality-content {
        grid-template-columns: 1fr;
    }

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

    .comparison-table {
        font-size: 0.9rem;
    }

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