:root {
    --primary-color: #2c3e50; /* Dark Blue/Gray */
    --secondary-color: #3498db; /* A slightly brighter blue for accents if needed */
    --accent-color: #e67e22; /* Orange for CTA */
    --light-gray: #f8f9fa;
    --dark-gray: #343a40;
    --text-color: #333;
    --white-color: #ffffff;
    --border-color: #dee2e6;
    --font-family: 'Roboto', sans-serif;
}

/* Basic Reset */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--white-color);
    font-size: 16px;
}

.container {
    width: 90%;
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 15px;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--primary-color);
    margin-bottom: 0.75em;
    line-height: 1.3;
    font-weight: 700;
}

h1 {
    font-size: 2.8rem; /* Responsive font size */
}

h2 {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 1.5em;
    position: relative;
}

h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background-color: var(--accent-color);
    margin: 0.5em auto 0;
}

p {
    margin-bottom: 1em;
}

a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* Utility Classes */
.section-padding {
    padding: 60px 0;
}

.section-bg-light {
    background-color: var(--light-gray);
}

.cta-button {
    display: inline-block;
    background-color: var(--accent-color);
    color: var(--white-color);
    padding: 12px 30px;
    border-radius: 5px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: background-color 0.3s ease, transform 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.cta-button:hover {
    background-color: #d35400; /* Darker orange */
    transform: translateY(-2px);
}

/* Header */
#main-header {
    background-color: var(--white-color);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 15px 0; /* Tăng padding */
}

#main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px; /* Thêm khoảng cách */
}

.logo a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.logo img {
    max-height: 60px; /* Tăng kích thước logo */
    width: auto;
    display: block;
}

nav ul {
    list-style: none;
    display: flex;
}

nav ul li {
    margin-left: 25px;
}

nav ul li a {
    color: var(--text-color);
    font-weight: 500;
    padding: 5px 0;
    position: relative;
    transition: color 0.3s ease;
}

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

nav ul li a:hover,
nav ul li a.active {
    color: var(--accent-color);
}

nav ul li a:hover::after,
nav ul li a.active::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none; /* Hidden by default, shown in mobile view */
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
}

/* Hero Section */
#hero {
    position: relative;
    min-height: 85vh; /* Use min-height for flexibility */
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--white-color);
    padding: 100px 20px; /* Add padding for content */
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5); /* Dark overlay */
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-content h1 {
    color: var(--white-color);
    margin-bottom: 0.5em;
    font-size: 3rem; /* Adjust as needed */
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 1.5em;
    font-weight: 400;
}

/* About Section */
.about-content {
    display: flex;
    flex-wrap: wrap; /* Allow wrapping on smaller screens */
    align-items: center;
    gap: 40px;
}

.about-text {
    flex: 1; /* Takes up available space */
    min-width: 300px; /* Minimum width before wrapping */
}

.about-images {
    flex-basis: 40%; /* Adjust width as needed */
    min-width: 280px;
}

/* Swiper Carousel for About Section */
.about-carousel {
    width: 100%;
    max-width: 538px; /* 500px + 38px */
    margin: 0 auto;
    position: relative;
}

.about-carousel .swiper-slide {
    display: flex;
    justify-content: center;
    align-items: center;
}

.about-carousel .swiper-slide img {
    max-width: 388px; /* 350px + 38px */
    max-height: 363px; /* 250px + 113px */
    width: auto;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    object-fit: cover;
}

.about-carousel .swiper-button-prev,
.about-carousel .swiper-button-next {
    color: var(--accent-color);
    background-color: rgba(255, 255, 255, 0.8);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.about-carousel .swiper-button-prev::after,
.about-carousel .swiper-button-next::after {
    font-size: 18px;
}

.about-carousel .swiper-pagination-bullet {
    background-color: var(--light-gray);
    opacity: 0.7;
}

.about-carousel .swiper-pagination-bullet-active {
    background-color: var(--accent-color);
    opacity: 1;
}

/* Pricing Section */
.pricing-table-wrapper {
    overflow-x: auto; /* Allows horizontal scrolling on small screens */
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5em;
    background-color: var(--white-color);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

thead {
    background-color: var(--primary-color);
    color: var(--white-color);
}

th, td {
    padding: 12px 15px;
    text-align: left;
    border: 1px solid var(--border-color);
}

tbody tr:nth-child(even) {
    background-color: var(--light-gray);
}

tbody tr:hover {
    background-color: #e9ecef;
}

.pricing-note {
    text-align: center;
    font-style: italic;
    color: var(--dark-gray);
    margin-top: 1em;
}

/* Contact Section */
.contact-content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
}

.contact-form-container {
    flex: 1;
    min-width: 300px;
}

.contact-info-container {
    flex-basis: 40%;
    min-width: 280px;
}

.contact-info-container h3 {
    margin-bottom: 1em;
    color: var(--primary-color);
}

.contact-info-container p {
    margin-bottom: 1em;
    display: flex;
    align-items: center;
}

.contact-info-container p i {
    color: var(--accent-color);
    margin-right: 10px;
    width: 20px; /* Ensure icons align */
    text-align: center;
}

.form-group {
    margin-bottom: 1.5em;
}

.form-group label {
    display: block;
    margin-bottom: 0.5em;
    font-weight: 500;
    color: var(--primary-color);
}

.form-group input[type="text"],
.form-group input[type="tel"],
.form-group input[type="email"],
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: var(--font-family);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input[type="text"]:focus,
.form-group input[type="tel"]:focus,
.form-group input[type="email"]:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
}

.form-group textarea {
    resize: vertical;
}

.map-container {
    margin-top: 2em;
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.map-container iframe {
    display: block; /* Remove extra space below iframe */
}

/* Footer */
#main-footer {
    background-color: var(--primary-color);
    color: var(--light-gray);
    padding: 40px 0 20px;
    margin-top: 60px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 30px;
    margin-bottom: 30px;
}

.footer-info p {
    margin-bottom: 0.5em;
    font-size: 0.9rem;
}

.footer-social a {
    color: var(--light-gray);
    font-size: 1.4rem;
    margin-left: 15px;
    transition: color 0.3s ease;
}

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

.footer-copyright {
    text-align: center;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #4e5d6c; /* Slightly lighter border */
    font-size: 0.85rem;
    color: #adb5bd;
}

/* Responsive Design */
@media (max-width: 992px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    .hero-content h1 { font-size: 2.5rem; }
    .hero-content p { font-size: 1.1rem; }
}

@media (max-width: 768px) {
    .container {
        width: 95%;
    }

    #nav-placeholder ul {
        display: none; /* Hide desktop nav */
        flex-direction: column;
        position: absolute;
        top: 100%; /* Position below header */
        left: 0;
        width: 100%;
        background-color: var(--white-color);
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        padding: 10px 0;
    }

    #nav-placeholder ul.active {
        display: flex; /* Show when active */
    }

    #nav-placeholder ul li {
        margin: 10px 20px;
        text-align: center;
    }

    .mobile-menu-toggle {
        display: block; /* Show hamburger icon */
    }

    .logo img {
        max-height: 50px; /* Giảm kích thước logo trên mobile */
    }

    #hero {
        min-height: 70vh;
    }

    .hero-content h1 { font-size: 2.2rem; }
    .hero-content p { font-size: 1rem; }

    .about-content,
    .contact-content {
        flex-direction: column;
        text-align: center;
    }

    .about-images,
    .contact-info-container {
        margin-top: 30px;
        flex-basis: auto;
        width: 100%;
        max-width: 400px; /* Limit width on mobile */
        margin-left: auto;
        margin-right: auto;
    }

    .about-carousel {
        max-width: 438px; /* 400px + 38px */
    }

    .about-carousel .swiper-slide img {
        max-width: 338px; /* 300px + 38px */
        max-height: 313px; /* 200px + 113px */
    }

    .about-carousel .swiper-button-prev,
    .about-carousel .swiper-button-next {
        width: 35px;
        height: 35px;
    }

    .about-carousel .swiper-button-prev::after,
    .about-carousel .swiper-button-next::after {
        font-size: 16px;
    }

    .contact-info-container p {
        justify-content: center;
    }

    .footer-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .footer-social {
        margin-top: 20px;
    }

    .footer-social a {
        margin: 0 10px;
    }
}

@media (max-width: 576px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.8rem; }
    .hero-content h1 { font-size: 1.8rem; }
    .cta-button {
        padding: 10px 25px;
        font-size: 0.9rem;
    }
    .section-padding {
        padding: 40px 0;
    }
    th, td {
        padding: 10px 8px;
        font-size: 0.9rem;
    }
}