* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Times New Roman', Times, serif;
}

.header {
    position: sticky;
    top: 0;
    background-color: white;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 10px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
}

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

.flag {
    width: 30px;
    height: 20px;
    margin-right: 10px;
}

.title {
    font-size: 24px;
    font-weight: bold;
    color: #ed2e2e;
    flex-grow: 1;
    text-align: left;
}

.home-button {
    background-color: #ed2e2e;
    color: white;
    border: none;
    font-weight: bold;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 16px;
}

.home-button:hover {
    background-color: #cc0000;
}

.timeline {
    display: flex;
    gap: 20px;
    margin: 0 20px;
}

.timeline a,
.sidebar a {
    text-decoration: none;
    color: #333;
    font-size: 1em;
    transition: color 0.3s ease, transform 0.2s ease;
    /* Hiệu ứng mượt mà */
}

.timeline a:hover,
.sidebar a:hover {
    color: #ed2e2e;
    transform: scale(1.05);
    /* Phóng to nhẹ khi hover */
}

.timeline a.active,
.sidebar a.active {
    color: #ed2e2e;
    font-weight: bold;
    border-bottom: 2px solid #ed2e2e;
    /* Đường gạch dưới khi active */
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 5px;
}

/* Sidebar styles */
.sidebar {
    position: fixed;
    top: 60px;
    left: -250px;
    width: 250px;
    height: 100%;
    background-color: white;
    box-shadow: 2px 0 5px rgba(0, 0, 0, 0.1);
    padding: 20px;
    transition: left 0.3s ease;
    z-index: 999;
}

.sidebar a {
    display: block;
    padding: 10px 0;
    text-decoration: none;
    color: #333;
    font-size: 16px;
}

.sidebar a:hover {
    color: #ed2e2e;
    transform: scale(1.05);
    /* Phóng to nhẹ khi hover */
}

/* Responsive design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: row;
        justify-content: space-between;
    }

    .timeline {
        display: none;
    }

    .menu-toggle {
        display: block;
    }

    .sidebar.active {
        left: 0;
    }

    .home-button {
        display: none;
    }
}

/* NỘI DUNG */
/* Main content styles */
.main-content {
    background-color: white;
    /* Màu nền xám nhạt như trong hình */
    min-height: calc(100vh - 60px);
    /* Đảm bảo chiều cao tối thiểu */
}

.intro-container {
    width: 100%;
    margin: 0 auto;
    text-align: center;
    background-color: #dddddd;
    /* Căn trái toàn bộ nội dung */
}

.content-columns {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 40px;
    padding: 50px;
}

.intro-column {
    flex: 1;
    padding-right: 20px;
}

.portrait-column {
    flex: 1;
    display: flex;
    justify-content: flex-end;
    /* Căn phải hình ảnh */
}

.main-title {
    font-size: 52px;
    color: #ed2e2e;
    font-weight: bold;
    margin-bottom: 20px;
}

.description {
    font-size: 16px;
    color: #333;
    line-height: 1.6;
    margin-bottom: 20px;
}

.learn-more {
    color: #66170b;
    border: none;
    background-color: #ffffff00;
    font-size: 20px;
    align-items: center;
    line-height: 35px;
    gap: 10px;
    transition: background-color 0.3s ease;
}

.arrow:hover {
    background-color: #7b3f10;
    /* Màu nâu đậm hơn khi hover */
}

.arrow {
    font-size: 12px;
    padding: 12px;
    border-radius: 50%;
    border: #66170b solid 2px;
}

.portrait-container {
    position: relative;
}

.portrait {
    max-width: 100%;
    /* Kích thước hình ảnh, có thể điều chỉnh */
    position: relative;
    z-index: 1;
}

/* Thêm viền đỏ và hiệu ứng như trong hình */
.portrait::after {
    content: '';
    position: absolute;
    top: -5px;
    left: -5px;
    right: -5px;
    bottom: -5px;
    border: 5px solid #ed2e2e;
    border-radius: 15px;
    z-index: 0;
    animation: glow 1.5s infinite alternate;
}

.shadow {
    box-shadow: 3px 15px 37px -14px rgba(0, 0, 0, 0.77);
}

.mt-6 {
    margin-top: 6rem !important;
    /* 1rem = 16px, nên 10rem = 160px */
}

.text-shadow {
    text-shadow: 3px 3px 9px rgba(0, 0, 0, 0.4);
}

@keyframes glow {
    from {
        box-shadow: 0 0 5px #ed2e2e, 0 0 10px #ed2e2e;
    }

    to {
        box-shadow: 0 0 10px #ed2e2e, 0 0 15px #ed2e2e;
    }
}

/* Responsive design */
@media (max-width: 768px) {
    .content-columns {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

    .intro-column,
    .portrait-column {
        width: 100%;
    }

    .portrait-column {
        justify-content: center;
        /* Căn giữa hình ảnh trên mobile */
    }

    .main-title {
        font-size: 36px;
    }

    .description {
        font-size: 14px;
    }

    .portrait {
        width: 100%;
        /* Giảm kích thước hình ảnh trên mobile */
    }

    .learn-more {
        padding: 8px 16px;
        font-size: 14px;
    }
}

/* Main Styles */
body {
    font-family: "Roboto", sans-serif;
    background-color: #fff;
    color: #333;
}

/* Typography */
.main-title {
    font-family: "Playfair Display", serif;
    font-size: 2.5rem;
    font-weight: 700;
    text-transform: uppercase;
}

.year-highlight {
    background-color: #ff0000;
    color: white;
    padding: 0.2rem 0.5rem;
}

.section-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: #ff0000;
    text-transform: uppercase;
}

/* Timeline Container */
.timeline-container {
    position: relative;
    padding-left: 50px;
}

/* Category Label */
.category-label {
    margin-bottom: 2rem;
    font-weight: 700;
    font-size: 1.2rem;
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 30px;
    border-left: 2px dashed #ff0000;
    margin-left: 15px;
}

/* Timeline Dots */
.timeline-dot {
    position: absolute;
    left: -47px;
    width: 20px;
    height: 20px;
    background-color: #ff0000;
    border-radius: 50%;
    top: 30px;
    border: 3px solid white;
    box-shadow: 0 0 0 2px #ff0000;
}

/* Timeline Items */
.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

/* Event Cards */
.event-card {
    background-color: #f0f0f0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* Event Header */
.event-header {
    padding: 1rem;
    position: relative;
}

/* Year Box */
.year-box {
    display: inline-block;
    background-color: #ff0000;
    color: white;
    padding: 0.3rem 0.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

/* Event Title */
.event-title {
    color: #ff0000;
    font-size: 1.2rem;
    font-weight: 700;
    text-transform: uppercase;
    margin-top: 0.5rem;
}

/* Event Description */
.event-description {
    padding: 0 1rem 1rem 1rem;
}

/* Event Image */
.event-image {
    padding: 1rem;
    position: relative;
}

.event-image img {
    border: 2px solid #ff0000;
    border-radius: 4px;
}

.image-caption {
    font-size: 0.8rem;
    text-align: center;
    margin-top: 0.5rem;
    color: #666;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .timeline-container {
        padding-left: 30px;
    }

    .timeline {
        padding-left: 15px;
    }

    .timeline-dot {
        left: -32px;
    }

    .main-title {
        font-size: 1.8rem;
    }

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

    .event-title {
        font-size: 1rem;
    }
}