/* --- General Setup & Variables --- */
@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@300;400;500;700&display=swap');

:root {
    --sand-yellow: #E0C9A6;
    --earth-brown: #6B4F4F;
    --dark-text: #333;
    --light-text: #FFFFFF;
    --background-light: #FDFBF5;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Be Vietnam Pro', sans-serif;
    line-height: 1.7;
    color: var(--dark-text);
    background-color: var(--background-light);
}

/* --- Reusable Components --- */
.container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
}

.cta-button {
    display: inline-block;
    padding: 12px 28px;
    background-color: var(--earth-brown);
    color: var(--light-text);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 500;
    transition: background-color 0.3s ease, transform 0.3s ease;
}

.cta-button:hover {
    background-color: #523a3a;
    transform: translateY(-3px);
}

/* --- Header --- */
.main-header {
    height: 100vh;
    background-image: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('https://tranhcatdong.com/bieudien/img/header-bieudien.jpg');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: var(--light-text);
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.header-content h1 {
    font-size: 3.5rem;
    margin-bottom: 0.5rem;
    letter-spacing: 2px;
    font-weight: 700;
}

.header-content .subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: 2rem;
}

/* --- Content Blocks --- */
.content-block {
    padding: 80px 0;
}

.content-block:nth-child(even) {
    background-color: #FFFFFF;
}

.content-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 4rem;
}

.text-content {
    flex: 1;
}

.text-content h2 {
    font-size: 2.5rem;
    color: var(--earth-brown);
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.image-content {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-content img {
    max-width: 100%;
    height: auto;
    object-fit: cover;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    transition: transform 0.4s ease-in-out;
}

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

.round-image {
    border-radius: 50%;
    width: 400px;
    height: 400px;
}

.square-image {
    border-radius: 20px;
    width: 400px;
    height: 400px;
}

/* Alternate layout for interwoven effect */
.alternate-layout .content-wrapper {
    flex-direction: row-reverse;
}

/* --- Animation on Scroll --- */
.animate-on-scroll {
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: scale(1);
}

/* --- Footer --- */
.main-footer {
    background-color: var(--earth-brown);
    color: var(--sand-yellow);
    padding: 40px 0;
    text-align: center;
}

.social-icons {
    margin-top: 1rem;
}

.social-icons a {
    color: var(--sand-yellow);
    margin: 0 15px;
    font-size: 1.5rem;
    transition: color 0.3s ease;
}

.social-icons a:hover {
    color: var(--light-text);
}

/* --- Zalo Popup --- */
.zalo-popup {
    position: fixed;
    bottom: 25px;
    right: 25px;
    width: 60px;
    height: 60px;
    z-index: 1000;
    transition: transform 0.3s ease;
}

.zalo-popup img {
    width: 100%;
    border-radius: 50%;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.zalo-popup:hover {
    transform: scale(1.1);
}

/* --- Responsive Design --- */
@media (max-width: 992px) {
    .header-content h1 {
        font-size: 2.8rem;
    }
    .header-content .subtitle {
        font-size: 1.2rem;
    }
    .text-content h2 {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .content-wrapper,
    .alternate-layout .content-wrapper {
        flex-direction: column;
        text-align: center;
    }

    .image-content {
        margin-top: 2rem;
    }

    .round-image, .square-image {
        width: 300px;
        height: 300px;
    }
}