a {
    color: #118bf0;              /* normal link */
    text-decoration: none; /* optional: underline */
    font-weight: 600;
  }

a:visited {
    color: blue;              /* visited link */
  }

a:hover {
    color: darkblue;          /* when hovering */
  }

a:active {
    color: navy;              /* when clicked */
  }

body {
    font-family: 'Poppins', sans-serif;
    color: #182c50;
    background-color: #f7f9fb;
}

.container {
    width: 100%;
    margin: 0 auto;
}

.logo {
    max-height: 50px;
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
}

nav ul li {
    margin-left: 20px;
}

nav ul li a {
    text-decoration: none;
    color: #182c50;
    font-weight: 400;
}

.article-nav {
    background-color: #f2f2f2 !important;
    width: 100%;
}

.article-nav .nav-link, .article-nav .navbar-brand {
    color: #182c50 !important;
}

.article-nav .navbar-brand {
    font-size: 1rem;
    font-weight: 600;
}

.hero {
    background: #fff url('../images/img_hero04.png') no-repeat 100% top; 
    background-size: cover;
    background-position: center;
    color: white;
    text-align: center;
    padding: 160px 0;
}

.hero h1 {
    font-size: 3rem;
    text-shadow: 0 1px 1px rgba(0, 0, 0, 0.5);
    color: #fff;
}

.tabs-section {
    padding: 80px 0;
    margin: 0;
}

.tabs {
    display: flex;
    justify-content: space-between;
    align-items: stretch;
    margin-bottom: 0px;
    border-bottom: 3px solid #118BF0;
    overflow-x: hidden;
}

/* Button */
.tabs button {
    background-color: white;
    float: left;
    border: none;
    outline: none;
    cursor: pointer;
    padding: 20px 30px;
    border: 1px solid transparent;
    border-top-left-radius: 24px;
    border-top-right-radius: 24px;
    border-bottom: none;
    transition: all 0.3s ease;
}

.tab-link {
    color: #182C50;;
    font-family: "Poppins", sans-serif;
    font-weight: 600;
    font-size: 1.2rem;
}

/* Tab Hover */
.tabs button:hover {
    border-color: #118BF0;
    background-color: #E2F1FE;
    color: #118BF0;
}

/* Active Tab */
.tabs button.active {
    background-color: #118BF0;
    color: white;
    border-color: #118BF0;
}

.tab-content {
    display: none;
    margin-top: 40px;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(30%, 1fr));
    gap: 30px;
}

.content-block {
    background-color: #ffffff;
    padding: 30px;
    border: 2px solid transparent;
    border-radius: 12px;
    border-color: #118BF0;
}

.content-block h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #182c50;
    margin-bottom: 24px;
}

.content-block ul {
    list-style: none;
    padding: 0;
    margin: 20px 0;
}

.content-block ul li {
    margin-bottom: 10px;
}

.content-block ul li a {
    text-decoration: none;
    color: #118BF0;
    font-size: 1rem;
}

.content-block .browse-button {
    background-color: #d9ebff;
    color: #118BF0;
    padding: 10px 20px;
    border-radius: 50px;
    text-decoration: none;
    display: inline-block;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.content-block a.browse-button:hover {
    background-color: #118BF0;
    color: white;
    opacity: 1;
}

.tabs-section .container {
    width: 90vw;
    margin: 0 auto;
}

.navigation-flow {
    font-size: 0.8rem;
    margin-bottom: 40px;
    margin-top: 20px;
}

.article {
    margin-bottom: 100px;
}

.article ol li {
    margin-bottom: 10px;
}

.date-label {
    color: rgba(24, 44, 80, 0.5);
}

.table-of-contents {
    position: sticky;
    top: 150px;
    margin-top: 50px;
}

.toc-vertical-line-container {
    position: relative;
    padding-left: 20px;
}

.toc-vertical-line-container::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 4px;
    height: 100%;
    background-color: #ccc;
}

.toc-vertical-line-container::after {
    content: '';
    position: absolute;
    left: 0;
    top: var(--active-top, 0);
    width: 4px;
    height: var(--active-height, 0);
    background-color: #118BF0;
    transition: top 0.3s ease, height 0.3s ease;
}

.table-of-contents ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.table-of-contents li {
    margin-bottom: 10px;
}

.table-of-contents a {
    color: rgba(24, 44, 80, 0.5);
    text-decoration: none;
    transition: color 0.3s ease;
}

.table-of-contents a.active {
    color: #118BF0;
    font-weight: 600;
}

.video-container {
    display: flex;
    margin-top: 50px;
    margin-bottom: 50px;
}

.article-image {
    max-width: 100%;
    height: auto;
}

.image-text-container {
    display: flex;
    margin-top: 50px;
    margin-bottom: 50px;
}

.image-text-container .image-container {
    flex: 1;
}

.image-text-container .image-container img {
    width: 100%;
    height: auto;
}

.image-text-container .text-container {
    flex: 1;
}

@media (max-width: 800px) {
    .tabs {
        display: flex;
        justify-content: space-between;
        align-items: stretch;
        margin-bottom: 0px;
        border-bottom: 3px solid #118BF0;
        overflow-x: scroll;
    }

    .table-of-contents {
        display: none;
    }

    .image-text-container {
        flex-direction: column;
    }

    .image-text-container .image-container {
        margin-right: 0;
        margin-bottom: 20px;
    }

    .image-text-container .text-container {
        margin-right: 0;
        margin-bottom: 20px;
    }

    #left {
        order: 2;
    }

    #right {
        order: 1;
    }

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

.navbar-toggler:focus,
.navbar-toggler:active {
   outline: none !important;
   box-shadow: none !important;
}