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

:root {
    --primary-blue: #1565c0;
    --dark-blue: #0d47a1;
    --light-gray: #f5f5f5;
    --medium-gray: #e0e0e0;
    --dark-gray: #424242;
    --white: #ffffff;
    --text-dark: #212121;
    --accent-blue: #42a5f5;
}

html {
    scroll-behavior: smooth;
}

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

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

/* ============ Navigation ============ */
.navbar {
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo img {
    height: 50px;
    width: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

    .nav-link:hover {
        color: var(--primary-blue);
    }

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

    .hamburger span {
        width: 25px;
        height: 3px;
        background-color: var(--text-dark);
        margin: 5px 0;
        transition: all 0.3s ease;
        border-radius: 2px;
    }

/* ============ Hero Section ============ */
.hero {
    text-align: center;
    width: 100%;
}

.hero-banner {
    width: 100%;
    object-fit: cover;
    object-position: center;
    display: block;
}


.hero-content {
    max-width: 600px;
}

.hero-logo-container {
    margin-bottom: 30px;
}

.hero-logo {
    height: 120px;
    width: auto;
    filter: brightness(0) invert(1);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    letter-spacing: 1px;
}

/* ============ Section Headers ============ */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

    .section-header h2 {
        font-size: 2.5rem;
        color: var(--primary-blue);
        margin-bottom: 10px;
        font-weight: 700;
    }

.section-subtitle {
    font-size: 1.1rem;
    color: var(--dark-gray);
}

/* ============ About Section ============ */
.about {
    padding: 80px 20px;
    background-color: var(--light-gray);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.about-card {
    background-color: var(--white);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-left: 4px solid var(--primary-blue);
}

    .about-card:hover {
        transform: translateY(-5px);
        box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
    }

    .about-card h3 {
        color: var(--primary-blue);
        margin-bottom: 15px;
        font-size: 1.3rem;
    }

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

/* ============ Projects Section ============ */
.projects {
    padding: 80px 20px;
    background-color: var(--white);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.project-card {
    background-color: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

    .project-card:hover {
        transform: translateY(-8px);
        box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15);
    }

.project-image {
    width: 100%;
    height: 250px;
    overflow: hidden;
    background-color: var(--light-gray);
}

    .project-image img {
        width: 100%;
        height: 100%;
        object-fit: cover;
        transition: transform 0.3s ease;
    }

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-info {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

    .project-info h3 {
        font-size: 1.4rem;
        color: var(--primary-blue);
        margin-bottom: 8px;
    }

.project-location {
    color: var(--dark-gray);
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.project-description {
    color: var(--dark-gray);
    font-size: 0.95rem;
    margin-bottom: 20px;
    flex: 1;
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.btn-detail {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s ease;
    text-align: center;
    font-weight: 600;
    display: inline-block;
}

    .btn-detail:hover {
        background-color: var(--dark-blue);
    }

/* ============ Contact Section ============ */
.contact {
    padding: 80px 20px;
    background-color: var(--light-gray);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    margin-top: 50px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item h4 {
    color: var(--primary-blue);
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.info-item p {
    color: var(--dark-gray);
    line-height: 1.8;
}

.info-item a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

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

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--medium-gray);
    border-radius: 4px;
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

    .form-group input:focus,
    .form-group textarea:focus {
        outline: none;
        border-color: var(--primary-blue);
    }

.btn-submit {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 15px 40px;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

    .btn-submit:hover {
        background-color: var(--dark-blue);
    }

/* ============ Footer ============ */
.footer {
    background-color: #0d47a1;
    color: var(--white);
    padding: 50px 20px 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.footer-section h4 {
    margin-bottom: 15px;
    color: #fff;
}

.footer-section p,
.footer-section ul {
    color: #fff;
}

.footer-section ul {
    list-style: none;
}

    .footer-section ul li {
        margin-bottom: 8px;
    }

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

    .footer-section a:hover {
        color: var(--white);
    }

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
}

/* ============ KNL Banner ============ */
.knl-banner {
    background-image: url("/images/banner..jpg");
    background-size: cover;
    background-position: center;
    position: relative;
    min-height: 220px;
    display: flex;
    align-items: center;
}

.knl-banner-inner {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}

.knl-banner-logo {
    height: 120px;
    width: auto;
    filter: drop-shadow(0 4px 12px rgba(0,0,0,.35));
}

/* ============ Project Detail Page ============ */
.project-detail-container {
    padding: 40px 20px 60px;
    min-height: calc(100vh - 200px);
}

.slider-section {
    margin-bottom: 60px;
}

.slider-container {
    position: relative;
    width: 100%;
    max-width: 900px;
    margin: 0 auto 20px;
    background-color: var(--light-gray);
    border-radius: 8px;
    overflow: hidden;
}

.slider {
    position: relative;
    width: 100%;
    padding-bottom: 62.5%;
    height: 0;
    overflow: hidden;
}

.slide {
    display: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

    .slide.active {
        display: block;
    }

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(0, 0, 0, 0.5);
    color: white;
    border: none;
    padding: 15px 20px;
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 10;
    transition: background-color 0.3s ease;
    border-radius: 4px;
}

    .slider-btn:hover {
        background-color: rgba(0, 0, 0, 0.8);
    }

    .slider-btn.prev {
        left: 20px;
    }

    .slider-btn.next {
        right: 20px;
    }

.slider-thumbnails {
    display: flex;
    gap: 10px;
    overflow-x: auto;
    padding: 10px 0;
    justify-content: center;
}

.thumbnail {
    width: 100px;
    height: 80px;
    object-fit: cover;
    cursor: pointer;
    border: 3px solid transparent;
    border-radius: 4px;
    transition: border-color 0.3s ease, transform 0.3s ease;
}

    .thumbnail:hover {
        transform: scale(1.05);
    }

    .thumbnail.active {
        border-color: var(--primary-blue);
    }

.project-detail-info {
    max-width: 900px;
    margin: 0 auto;
}

    .project-detail-info h1 {
        font-size: 2.5rem;
        color: var(--primary-blue);
        margin-bottom: 10px;
    }

.project-detail-location {
    color: var(--dark-gray);
    font-size: 1.1rem;
    margin-bottom: 30px;
}

.project-meta {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    background-color: var(--light-gray);
    padding: 30px;
    border-radius: 8px;
    margin-bottom: 40px;
}

.meta-item h4 {
    color: var(--primary-blue);
    margin-bottom: 8px;
    font-weight: 600;
}

.meta-item p {
    color: var(--text-dark);
    font-size: 1.1rem;
}

.project-description-box,
.project-features {
    margin-bottom: 40px;
}

    .project-description-box h3,
    .project-features h3 {
        font-size: 1.5rem;
        color: var(--primary-blue);
        margin-bottom: 15px;
    }

    .project-description-box p {
        color: var(--dark-gray);
        line-height: 1.8;
        font-size: 1rem;
    }

    .project-features ul {
        list-style: none;
        color: var(--dark-gray);
    }

        .project-features ul li {
            padding: 10px 0;
            padding-left: 30px;
            position: relative;
            line-height: 1.8;
        }

            .project-features ul li:before {
                content: "✓";
                position: absolute;
                left: 0;
                color: var(--primary-blue);
                font-weight: bold;
                font-size: 1.2rem;
            }

.project-contact {
    background-color: var(--light-gray);
    padding: 30px;
    border-radius: 8px;
    margin-bottom: 40px;
}

    .project-contact h3 {
        color: var(--primary-blue);
        margin-bottom: 15px;
        font-size: 1.3rem;
    }

    .project-contact p {
        color: var(--dark-gray);
        margin-bottom: 20px;
        line-height: 1.8;
    }

.contact-links {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.btn-call,
.btn-zalo {
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
    text-align: center;
}

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

    .btn-call:hover {
        background-color: var(--dark-blue);
    }

.btn-zalo {
    background-color: #0084ff;
    color: var(--white);
}

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

.btn-back {
    display: inline-block;
    background-color: var(--medium-gray);
    color: var(--text-dark);
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    transition: background-color 0.3s ease;
}

    .btn-back:hover {
        background-color: var(--dark-gray);
        color: var(--white);
    }

    img{
        width: 100%;
    }

/* ============ Responsive Design ============ */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hamburger {
        display: flex;
    }

        .hamburger.active span:nth-child(1) {
            transform: rotate(-45deg) translate(-8px, 8px);
        }

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

        .hamburger.active span:nth-child(3) {
            transform: rotate(45deg) translate(-8px, -8px);
        }

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

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .section-header h2 {
        font-size: 1.8rem;
    }

    .hero-banner {
        height: 280px;
        object-position: center;
    }

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

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

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

    .project-detail-info h1 {
        font-size: 1.8rem;
    }

    .slider-btn {
        padding: 10px 15px;
        font-size: 1.2rem;
    }

        .slider-btn.prev {
            left: 10px;
        }

        .slider-btn.next {
            right: 10px;
        }
}

@media (max-width: 480px) {
    .nav-logo img {
        height: 40px;
    }

    .nav-container {
        height: 60px;
        display: flex;
        justify-content: space-between;
        width: 100%;
    }

    .hero-logo {
        height: 80px;
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-subtitle {
        font-size: 0.9rem;
    }

    .section-header h2 {
        font-size: 1.5rem;
    }

    .hero-banner {
        height: 240px;
        object-position: center;
    }

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

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

    .contact-links {
        flex-direction: column;
    }

    .btn-call,
    .btn-zalo {
        width: 100%;
    }

    .slider-btn {
        padding: 8px 12px;
        font-size: 1rem;
    }

    .slider-thumbnails {
        padding: 8px 0;
    }

    .thumbnail {
        width: 80px;
        height: 60px;
    }
}