:root {
    --primary-color: #c41e3a;
    --primary-dark: #a01729;
    --white: #ffffff;
    --bg-light: #f8f8f8;
    --text-dark: #333;
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-medium: rgba(196, 30, 58, 0.3);
    --shadow-strong: rgba(196, 30, 58, 0.4);
}

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

body {
    background-color: var(--bg-light);
    font-family: 'Montserrat', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

.main-container {
    max-width: 1200px;
    width: 100%;
    margin: 30px auto;
    padding: 0 20px;
}

.article-card {
    background: var(--white);
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--shadow-light);
    overflow: hidden;
    transition: box-shadow 0.3s ease;
}

.article-header {
    padding: 40px;
    position: relative;
}

.article-header h1 {
    font-size: clamp(24px, 3vw, 32px);
    font-weight: 600;
    line-height: 1.3;
    margin: 0 0 20px;
    color: var(--text-dark);
}

.date-container {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-dark);
}

.date-container i {
    font-size: 18px;
    opacity: 0.9;
    color: var(--primary-color);
}

.article-content {
    padding: 0 40px 40px;
}

/* Image Slider - Centered */
.slider-section {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 40px;
}

.image-slider {
    width: 100%;
    max-width: 800px;
    position: relative;
    overflow: hidden;
    height: 450px;
    border-radius: 12px;
    box-shadow: 0 4px 20px var(--shadow-light);
}

.slider {
    width: 100%;
    height: 100%;
    position: relative;
}

.slider img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}

.slider img.active {
    opacity: 1;
    z-index: 1;
}

.navigation-button {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 10;
}

.dot {
    cursor: pointer;
    height: 12px;
    width: 12px;
    background-color: rgba(255, 255, 255, 0.6);
    border-radius: 50%;
    transition: all 0.3s ease;
}

.dot.active,
.dot:hover {
    background-color: var(--primary-color);
    transform: scale(1.2);
}

.prev,
.next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(0, 0, 0, 0.4);
    color: var(--white);
    border: none;
    padding: 12px 16px;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    z-index: 10;
    border-radius: 4px;
    user-select: none;
}

.prev {
    left: 10px;
}

.next {
    right: 10px;
}

.prev:hover,
.next:hover {
    background-color: var(--primary-color);
    transform: translateY(-50%) scale(1.1);
}

.prev:active,
.next:active {
    transform: translateY(-50%) scale(0.95);
}

/* Bio Paragraph Section */
.bio-paragraph {
    background: linear-gradient(135deg, #fff8f5 0%, #fff0e6 100%);
    border-radius: 12px;
    padding: 32px;
    border: 1px solid rgba(196, 30, 58, 0.1);
    position: relative;
    font-size: 16px;
    line-height: 1.8;
    color: var(--text-dark);
}

.bio-paragraph::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-dark));
    border-radius: 12px 12px 0 0;
}

.bio-paragraph p {
    margin-bottom: 1.5em;
}

.bio-paragraph p:last-child {
    margin-bottom: 0;
}

/* Back Button */
.back-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--white);
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 25px;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    margin-bottom: 20px;
    box-shadow: 0 4px 12px var(--shadow-medium);
}

.back-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--shadow-strong);
    background: linear-gradient(135deg, #333, #222);
}

.back-button i {
    transition: transform 0.3s ease;
}

.back-button:hover i {
    transform: translateX(-4px);
}

/* Scroll Container for IEOR Highlights */
.scroll-container {
    margin: 0 auto;
    text-align: center;
    background: #f5f5f5;
    padding: 15px;
    border-radius: 20px;
    box-shadow: 2px 2px 10px var(--shadow-light);
    width: 280px;
    border: 1px solid #ccc;
}

.scroll-container h2 {
    font-size: 25px;
    font-weight: 600;
    background: var(--primary-color);
    color: var(--white);
    padding: 15px 0;
    border-radius: 3px 3px 0 0;
    margin: -15px -15px 15px -15px;
}

.scroll-wrapper {
    height: 280px;
    overflow: hidden;
    position: relative;
}

.scroll-list {
    list-style-type: none;
    padding: 0;
    margin: 0;
    position: absolute;
    width: 100%;
}

.scroll-list li {
    padding: 15px 12px;
    background: #d5d5f1;
    color: black;
    border-bottom: 1px solid var(--white);
    transition: background 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 80px;
}

.scroll-list li .number {
    font-size: 32px;
    font-weight: bold;
    line-height: 1;
    margin-bottom: 8px;
}

.scroll-list li .label {
    font-size: 14px;
    font-weight: 500;
}

.scroll-list li:hover {
    background: #e9ecef;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-container {
        padding: 0 15px;
        margin: 20px auto;
    }

    .article-header,
    .article-content {
        padding: 30px 20px;
    }

    .image-slider {
        height: 300px;
        max-width: 100%;
    }

    .bio-paragraph {
        padding: 24px;
    }

    .prev,
    .next {
        padding: 8px 12px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .article-header h1 {
        font-size: 20px;
    }

    .date-container {
        font-size: 14px;
    }

    .image-slider {
        height: 250px;
        border-radius: 8px;
    }

    .bio-paragraph {
        padding: 20px;
        font-size: 14px;
    }
}