/* ===== BASE STYLES ===== */
:root {
    --primary-color: #1a0b3b;
    --secondary-color: #f5f5f5;
    --accent-color: #e6b800;
    --text-color: #333333;
    --light-text: #ffffff;
    --dark-bg: #0d0d0d;
    --border-color: #dddddd;
    --transition-speed: 0.4s;
    --box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
    --glass-bg: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.3);
}

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

body {
    font-family: 'Montserrat', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    overflow-x: hidden;
    background: #000 !important; /* Đen tuyệt đối */
    position: relative;
    animation: none;
}

@keyframes gradientAnimation {
    0% { background: linear-gradient(135deg, #2a004a 0%, #0d0d0d 70%, #e6b800 100%); }
    50% { background: linear-gradient(135deg, #0d0d0d 0%, #e6b800 30%, #2a004a 100%); }
    100% { background: linear-gradient(135deg, #2a004a 0%, #0d0d0d 70%, #e6b800 100%); }
}

body.light-mode {
    background: linear-gradient(135deg, #f0e6d2 0%, #fff5e1 70%, #ffd700 100%);
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: none !important; /* Không dùng ảnh nền */
    opacity: 0;
    z-index: -1;
    filter: none;
}

body.light-mode::before {
    background: url('../../Images/art-background-light.jpg') no-repeat center/cover;
    opacity: 0.4;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all var(--transition-speed) ease;
}

ul {
    list-style: none;
}

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

.container {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== PARTICLES BACKGROUND ===== */
.particles-bg {
    position: fixed;
    top: 0; left: 0;
    width: 100vw; height: 100vh;
    z-index: 0;
    pointer-events: none;
}

@media (max-width: 768px) {
    .particles-bg {
        display: none;
    }
}

/* ===== GLASS EFFECT ===== */
.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    box-shadow: var(--box-shadow);
}

@supports not (backdrop-filter: blur(15px)) {
    .glass {
        background: rgba(255, 255, 255, 0.2);
    }
}

/* ===== NAVBAR STYLES ===== */
nav {
    position: sticky;
    top: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 100;
    padding: 15px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background 0.3s ease;
}

nav.light-mode {
    background: rgba(255, 255, 255, 0.8);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 15px;
}

.logo-container {
    display: flex;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    cursor: pointer;
    color: #fff;
    transition: color 0.3s ease;
    margin-right: 25px;
}

.logo:hover {
    color: #ffd700;
}

.nav-links {
    display: flex;
    gap: 25px;
    list-style: none;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-links li a {
    color: #fff;
    text-decoration: none;
    font-size: 1.1rem;
    position: relative;
    padding: 8px 15px;
    transition: color 0.3s ease;
}

.nav-links li a .icon {
    margin-right: 8px;
}

.nav-links li a:hover {
    color: #ffd700;
}

.nav-links li a:hover::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, #ff6f61, #ffd700);
    bottom: -5px;
    left: 0;
    animation: underline 0.3s forwards;
}

@keyframes underline {
    from { width: 0; }
    to { width: 100%; }
}

/* Dropdown Menu */
.dropdown {
    position: relative;
}

.dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: rgba(0, 0, 0, 0.9);
    padding: 10px 15px;
    border-radius: 10px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    min-width: 200px;
    z-index: 10;
    transition: opacity 0.2s ease;
    opacity: 0;
}

.dropdown-menu a {
    display: block;
    color: #fff;
    text-decoration: none;
    padding: 8px 15px;
    font-size: 0.9rem;
    transition: background 0.3s ease;
}

.dropdown-menu a:hover {
    background: rgba(255, 255, 255, 0.1);
}

.dropdown:hover .dropdown-menu {
    display: block;
    opacity: 1;
}

/* Search Bar */
.search-bar {
    display: flex;
    align-items: center;
}

.search-bar input {
    padding: 8px 15px;
    border: none;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    outline: none;
    font-size: 1rem;
    width: 180px;
    transition: width 0.3s ease;
}

.search-bar input:focus {
    width: 220px;
}

/* Login Button */
.login-btn {
    padding: 8px 20px;
    background: #ff6f61;
    border: none;
    border-radius: 20px;
    color: #fff;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s ease, transform 0.3s ease;
}

.login-btn:hover {
    background: #ffd700;
    transform: scale(1.05);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    left: -100%;
    width: 250px;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 200;
    padding: 20px;
    transition: left 0.5s ease;
}

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

.mobile-menu ul {
    list-style: none;
    margin-top: 50px;
}

.mobile-menu ul li {
    margin: 20px 0;
    display: flex;
    align-items: center;
    gap: 10px;
}

.mobile-menu ul li a {
    color: #fff;
    text-decoration: none;
    font-size: 1.1rem;
}

.hamburger {
    display: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: #fff;
    margin-right: 15px;
}

/* ===== FULL-SCREEN SECTIONS ===== */
.full-screen-sections {
    min-height: 100vh;
    overflow-y: auto;
    scroll-snap-type: y mandatory;
}

.section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    scroll-snap-align: start;
    position: relative;
    padding: 0 20px;
}

/* ===== INTRO SECTION (HEADER) ===== */
.intro-section {
    position: relative;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.intro-video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 75%;
    object-fit: cover;
    z-index: -1;
}

.intro-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 0;
}

.intro-content {
    position: relative;
    text-align: center;
    z-index: 1;
    max-width: 800px;
    padding: 20px;
}

.intro-title {
    font-family: 'Playfair Display', serif;
    font-size: 72px;
    color: var(--light-text);
    text-shadow: 0 5px 15px rgba(230, 184, 0, 0.7);
}

.intro-text {
    font-size: 24px;
    color: var(--light-text);
    opacity: 0.9;
    margin: 20px 0;
}

/* ===== HERO SECTION (INTRODUCE) ===== */
.hero-section {
    position: relative;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, rgba(42, 0, 74, 0.8), rgba(13, 13, 13, 0.6));
}

.hero-content {
    text-align: center;
    max-width: 800px;
    padding: 40px;
    background: var(--glass-bg);
    border-radius: 20px;
    backdrop-filter: blur(20px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.5);
}

.hero-content h1 {
    font-family: 'Playfair Display', serif;
    font-size: 56px;
    color: var(--light-text);
    text-shadow: 0 5px 15px rgba(230, 184, 0, 0.7);
}

.hero-content p {
    font-size: 20px;
    color: var(--light-text);
    opacity: 0.9;
    margin: 20px 0;
    line-height: 1.8;
}

.cta-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 15px 40px;
    background: linear-gradient(135deg, var(--accent-color), #ff8c00);
    color: var(--dark-bg);
    border: none;
    border-radius: 30px;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-speed) ease;
}

.cta-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(230, 184, 0, 0.8);
}

/* ===== EVENT SECTION ===== */
.event-section {
    position: relative;
    height: 100vh;
    padding: 0;
}

.event-swiper {
    width: 100%;
    height: 100%;
}

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

.event-card {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 40px;
    background: linear-gradient(135deg, rgba(42, 0, 74, 0.8), rgba(13, 13, 13, 0.6));
}

.event-card-content {
    flex: 1;
    padding: 40px;
    background: var(--glass-bg);
    border-radius: 20px;
    color: var(--light-text);
    height: 80%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.event-card-media {
    flex: 1;
    height: 80%;
    border-radius: 20px;
    overflow: hidden;
}

.event-card-media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: brightness(0.9);
    transition: transform 0.5s ease, filter 0.5s ease;
}

.event-card-media img:hover {
    transform: scale(1.05);
    filter: brightness(1.1);
}

.event-card-content h3 {
    font-family: 'Playfair Display', serif;
    font-size: 48px;
    margin-bottom: 20px;
    text-shadow: 0 3px 10px rgba(230, 184, 0, 0.5);
}

.event-card-content p {
    font-size: 18px;
    margin-bottom: 20px;
    opacity: 0.9;
}

.event-card-content .event-date,
.event-card-content .event-address {
    font-size: 16px;
    margin-bottom: 10px;
}

.event-card-content .countdown-timer {
    font-size: 24px;
    color: var(--accent-color);
    margin-bottom: 20px;
    font-weight: 500;
}

.event-card-content .learn-more {
    display: inline-block;
    padding: 15px 40px;
    background: linear-gradient(135deg, var(--accent-color), #ff8c00);
    color: var(--dark-bg);
    border-radius: 30px;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
}

.event-card-content .learn-more:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(230, 184, 0, 0.8);
}

.swiper-button-next,
.swiper-button-prev {
    color: var(--accent-color);
}

.swiper-pagination-bullet {
    background: var(--accent-color);
    opacity: 0.5;
}

.swiper-pagination-bullet-active {
    opacity: 1;
}

/* ===== REGISTRATION SECTION ===== */
.registration-section {
    position: relative;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.registration-content {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px;
    border-radius: 20px;
    background: var(--glass-bg);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.5);
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: var(--light-text);
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 15px 12px 40px;
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--light-text);
    font-size: 14px;
    transition: all 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent-color);
    background: rgba(255, 255, 255, 0.2);
    box-shadow: 0 0 10px rgba(230, 184, 0, 0.3);
}

.form-group input.error,
.form-group select.error {
    border-color: #ff4d4d;
    background: rgba(255, 77, 77, 0.1);
}

.form-group input.valid,
.form-group select.valid {
    border-color: #4dff4d;
    background: rgba(77, 255, 77, 0.1);
}

.input-wrapper {
    position: relative;
}

.input-icon {
    position: absolute;
    top: 50%;
    left: 15px;
    transform: translateY(-50%);
    color: rgba(255, 255, 255, 0.7);
    font-size: 18px;
}

.error-message {
    color: #ff4d4d;
    font-size: 12px;
    margin-top: 5px;
    display: block;
}

.form-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-top: 20px;
}

.register-btn,
.cancel-btn {
    width: 200px;
    padding: 15px;
    border: none;
    border-radius: 30px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.register-btn {
    background: linear-gradient(135deg, var(--accent-color), #ff8c00);
    color: var(--dark-bg);
}

.register-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 20px rgba(230, 184, 0, 0.6);
}

.cancel-btn {
    background: linear-gradient(135deg, #ff4d4d, #ff1a1a);
    color: var(--light-text);
}

.cancel-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 20px rgba(255, 77, 77, 0.6);
}

.loading-spinner {
    color: var(--light-text);
    font-size: 16px;
    text-align: center;
    margin-top: 15px;
}

/* ===== TESTIMONIAL SECTION ===== */
.testimonial-section {
    position: relative;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.testimonial-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 50px;
    text-align: center;
}

.testimonial-content h2 {
    font-family: 'Playfair Display', serif;
    font-size: 40px;
    color: var(--light-text);
    margin-bottom: 40px;
    text-shadow: 0 3px 10px rgba(230, 184, 0, 0.5);
}

.testimonial-carousel {
    display: flex;
    gap: 30px;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    padding-bottom: 20px;
}

.testimonial-card {
    flex: 0 0 300px;
    background: var(--glass-bg);
    padding: 25px;
    border-radius: 15px;
    color: var(--light-text);
    scroll-snap-align: start;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
}

.testimonial-card img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    margin-bottom: 20px;
    object-fit: cover;
    border: 2px solid var(--accent-color);
}

.testimonial-card p {
    font-size: 16px;
    margin-bottom: 15px;
    opacity: 0.9;
}

.testimonial-card h4 {
    font-size: 18px;
    font-weight: 500;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

/* ===== MODAL STYLES ===== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1002;
    display: flex;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: var(--dark-bg);
    padding: 40px;
    border-radius: 20px;
    max-width: 500px;
    text-align: center;
    color: var(--light-text);
    position: relative;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.5);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 24px;
    cursor: pointer;
    color: var(--light-text);
    transition: all var(--transition-speed) ease;
}

.modal-close:hover {
    color: var(--accent-color);
    transform: rotate(90deg);
}

.modal-content p {
    font-size: 20px;
    margin-top: 20px;
}

/* ===== MODE TOGGLE ===== */
.mode-toggle {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #2a004a 0%, #e6b800 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    cursor: pointer;
    box-shadow: var(--box-shadow);
    z-index: 100;
    transition: all var(--transition-speed) ease;
}

.mode-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 0 20px rgba(230, 184, 0, 0.8);
}

/* ===== FOOTER ===== */
footer {
    padding: 40px 20px;
    text-align: center;
    background: linear-gradient(135deg, #2a004a 0%, #0d0d0d 100%);
    color: var(--light-text);
    border-top: 1px solid rgba(230, 184, 0, 0.2);
}

.footer-links {
    margin-bottom: 20px;
}

.footer-links a {
    margin: 0 15px;
    color: var(--light-text);
    font-size: 14px;
    transition: all var(--transition-speed) ease;
}

.footer-links a:hover {
    color: var(--accent-color);
    text-shadow: 0 0 10px rgba(230, 184, 0, 0.5);
}

.footer-social {
    margin: 20px 0;
}

.footer-social a {
    margin: 0 15px;
    color: var(--light-text);
    font-size: 24px;
    transition: all var(--transition-speed) ease;
}

.footer-social a:hover {
    color: var(--accent-color);
    transform: translateY(-3px);
    text-shadow: 0 0 10px rgba(230, 184, 0, 0.5);
}

/* ===== RESPONSIVE STYLES ===== */
@media (max-width: 1024px) {
    .nav-links {
        display: none;
    }
    .hamburger {
        display: block;
    }
}

@media (max-width: 768px) {
    .intro-title, .hero-content h1 {
        font-size: 48px;
    }
    .intro-text, .hero-content p {
        font-size: 18px;
    }
    .section {
        flex-direction: column;
        padding: 0 20px;
    }
    .intro-content, .hero-content, .registration-content, .testimonial-content {
        width: 100%;
        height: auto;
        padding: 20px;
    }
    .event-card {
        flex-direction: column;
        padding: 20px;
    }
    .event-card-content, .event-card-media {
        height: auto;
        width: 100%;
    }
    .event-card-media img {
        height: 50vh;
    }
    .form-grid {
        grid-template-columns: 1fr;
    }
    .register-btn, .cancel-btn {
        width: 100%;
    }
    .testimonial-carousel {
        flex-direction: row;
    }
}

@media (max-width: 576px) {
    .intro-title, .hero-content h1 {
        font-size: 36px;
    }
    .intro-text, .hero-content p {
        font-size: 16px;
    }
    .event-card-content h3 {
        font-size: 36px;
    }
    .registration-content h2, .testimonial-content h2 {
        font-size: 32px;
    }
}
.intro-title-wrapper {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 3vw; /* hoặc 30px, tuỳ ý */
    width: 100%;
    display: flex;
    justify-content: center;
    z-index: 2;
    pointer-events: none;
}

.intro-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 5vw;
    color: #fff;
    font-weight: bold;
    letter-spacing: 0.1em;
    text-shadow: 0 4px 24px #000, 0 2px 8px #e6b800;
    padding: 0.2em 1em;
    border-radius: 10px;
    pointer-events: auto;
}
.intro-quote {
    width: 100%;
    max-width: 900px;
    margin: 40px auto 0 auto;
    text-align: center;
    color: #fff;
    z-index: 3;
    position: relative;
}

.intro-quote p {
    font-size: 2vw;
    font-family: 'Montserrat', sans-serif;
    font-weight: 400;
    margin-bottom: 16px;
    line-height: 1.5;
}

.intro-quote span {
    font-size: 1.1vw;
    color: #aaa;
    font-family: 'Montserrat', monospace;
    opacity: 0.7;
}
.mission-section {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 80vh;
    background: #000;
    background: transparent !important;
}

.mission-content {
    display: flex;
    gap: 60px;
    align-items: center;
    width: 80%;
    max-width: 1400px;
}

.mission-text {
    flex: 1;
    color: #fff;
}

.mission-text h2 {
    font-size: 3vw;
    font-weight: bold;
    letter-spacing: 0.1em;
    margin-bottom: 30px;
}

.mission-text p {
    font-size: 1.4vw;
    line-height: 1.7;
    color: #fff;
}

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

.mission-image img {
    width: 70%;
    max-width: 500px;
    border-radius: 18px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    object-fit: cover;
}
@media (max-width: 900px) {
    .mission-content {
        flex-direction: column;
        gap: 30px;
    }
    .mission-text h2 {
        font-size: 32px;
    }
    .mission-text p {
        font-size: 18px;
    }
}
.timeline-section {
    background: #000;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 80vh;
}
.timeline-container {
    display: flex;
    gap: 60px;
    align-items: flex-start;
    width: 90%;
    max-width: 1600px;
}
.timeline-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}
.timeline-image img {
    width: 200%;
    max-width: 500px;
    aspect-ratio: 16/10;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.4);
    object-fit: cover;
    background: #222;
}
.timeline-content {
    flex: 2;
    display: flex;
    align-items: flex-start;
    gap: 40px;
}
.timeline-list {
    list-style: none;
    padding: 0;
    margin: 0 40px 0 0;
    display: flex;
    flex-direction: column;
    gap: 18px;
    min-width: 180px;
}
.timeline-list li {
    color: #888;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 8px 18px;
    border-radius: 6px;
    border: 2px solid transparent;
    transition: all 0.2s;
    position: relative;
    background: none;
}
.timeline-list li.active,
.timeline-list li:hover {
    color: #fff;
    border: 2px solid #fff;
    background: #111;
    font-weight: 600;
}
.timeline-list li.active::before {
    content: '';
    position: absolute;
    left: -22px;
    top: 50%;
    transform: translateY(-50%);
    width: 12px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
}
.timeline-detail {
    flex: 1;
    color: #fff;
    min-width: 320px;
    max-width: 600px;
    margin-top: 0;
}
.timeline-detail h3 {
    font-size: 2.2rem;
    margin-bottom: 18px;
    font-weight: 700;
}
.timeline-detail p {
    font-size: 1.15rem;
    line-height: 1.7;
    color: #eee;
}
@media (max-width: 1100px) {
    .timeline-container {
        flex-direction: column;
        gap: 30px;
        align-items: center;
    }
    .timeline-content {
        flex-direction: column;
        gap: 20px;
        align-items: flex-start;
    }
    .timeline-list {
        flex-direction: row;
        gap: 10px;
        margin: 0 0 20px 0;
        min-width: unset;
    }
    .timeline-detail {
        max-width: 100%;
    }
}
@media (max-width: 700px) {
    .timeline-image img {
        max-width: 100vw;
    }
    .timeline-section {
        padding: 0 10px;
    }
}
.mission-content.reverse {
    flex-direction: row-reverse;
}
@media (max-width: 900px) {
    .mission-content.reverse {
        flex-direction: column;
    }
}
/* Ẩn particles ở phần intro-section bằng một lớp phủ */
.intro-section::before {
    content: '';
    position: absolute;
    z-index: 1;
    top: 0; left: 0; right: 0; bottom: 0;
    width: 100%;
    height: 100%;
    opacity: 1;       /* 1 là che hoàn toàn, 0.8 là hơi trong suốt */
    pointer-events: none;
}
.intro-section {
    position: relative;
    z-index: 2;
}