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

:root {
    --primary-color: #4995D6;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --light-bg: #f3f4f6;
    --border-color: #e5e7eb;
    --radius: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    color: var(--text-color);
    background-color: #ffffff;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding-top: 100px;
}

/* Top Header (not used) */
.top-header {
    height: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    display: flex;
    align-items: center;
    padding: 0 20px;
    font-size: 12px;
    font-weight: 500;
}

.top-header-content {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

/* Main Header */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 100px;
    background-color: #4995D6;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    padding: 0 20px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Logo Placeholder */
.logo-placeholder {
    min-width: 120px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 18px;
}

/* Logo button inside header: prevent topic-btn styles from affecting image position/color */
.header-logo .logo-btn {
    background: none;
    border: none;
    padding: 0;
    margin: 0;
    display: inline-flex;
    align-items: center;
    cursor: pointer;
}

.header-logo .logo-btn img {
    display: block;
    height: 80px;
    width: auto;
}

.header-logo .logo-btn:hover,
.header-logo .logo-btn:focus,
.header-logo .logo-btn.active {
    background: none;
    color: inherit;
    transform: none;
}

/* Navigation */
.main-nav {
    flex: 1;
    display: flex;
    justify-content: center;
    margin: 0 100px;
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 15px;
}

.topic-btn {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    padding: 8px 16px;
    border-radius: var(--radius);
    transition: all 0.3s ease;
    position: relative;
}

.topic-btn:hover {
    background-color: var(--light-bg);
    color: var(--primary-color);
}

.topic-btn.active {
    background-color: var(--primary-color);
    color: white;
}

/* Dropdown styles */
.dropdown-container {
    position: relative;
}

.dropdown-container::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 8px;
    pointer-events: auto;
}

.dropdown-toggle {
    display: inline-flex;
    align-items: center;
}

.dropdown-list {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    background: white;
    box-shadow: 0 6px 18px rgba(31,41,55,0.12);
    list-style: none;
    padding: 8px 0;
    margin: 0;
    min-width: 160px;
    border-radius: 6px;
    z-index: 40;
}

.dropdown-list li {
    padding: 0;
}

.dropdown-list .topic-btn {
    display: block;
    width: 100%;
    text-align: left;
    padding: 8px 14px;
    margin: 0;
    border-radius: 0;
}

.dropdown-list .topic-btn:hover {
    background-color: var(--light-bg);
    color: var(--primary-color);
}

.dropdown-container:hover .dropdown-list,
.dropdown-toggle.active + .dropdown-list {
    display: block;
}

/* Dropdown items show active state like header buttons */
.dropdown-list .topic-btn.active {
    background-color: var(--primary-color);
    color: white;
}

/* Mobile: only show a dropdown list when its toggle is active (clicked) */
.main-nav.active .dropdown-toggle.active + .dropdown-list {
    display: block;
    position: static;
    box-shadow: none;
    padding-left: 10px;
}

/* Burger Menu Button */
.burger-menu-btn {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 6px;
    padding: 8px;
    border-radius: var(--radius);
    transition: background-color 0.3s ease;
}

.burger-menu-btn:hover {
    background-color: var(--light-bg);
}

.burger-menu-btn span {
    display: block;
    width: 24px;
    height: 3px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: all 0.3s ease;
}

.burger-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(10px, 10px);
}

.burger-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.burger-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* Main Container */
.main-container {
    flex: 1;
    display: flex;
    padding: 0;
    background-color: var(--light-bg);
    overflow-y: auto;
}

/* Body Section */
.body-section {
    width: 100%;
    max-width: 100%;
    height: 850px;
    margin: 0;
    background-color: white;
    border-radius: 0;
    box-shadow: none;
    overflow-y: auto;
}

.content-wrapper {
    padding: 40px;
    animation: fadeIn 0.3s ease;
}

.content-wrapper h2 {
    color: var(--primary-color);
    font-size: 32px;
    margin-bottom: 20px;
}

.content-wrapper p {
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

/* Bottom Section (Footer) */
.bottom-section {
    height: 300px;
    background-color: #2F3234;
    color: white;
    padding: 40px 20px 20px;
    border-top: 1px solid var(--border-color);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
}

.footer-column h3 {
    font-size: 16px;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.footer-column ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

.footer-column ul li {
    margin-bottom: 0;
}

.footer-column a,
.footer-link {
    color: #d1d5db;
    text-decoration: none;
    border-radius: 4px;
    padding: 4px 8px;
    display: inline-block;
    background: none;
    border: none;
    font-size: 16px;
    cursor: pointer;
    font-family: inherit;
}

.footer-column a:hover {
    color: var(--primary-color);
}

.footer-link:hover,
.footer-link.active {
    color: #d1d5db;
    background: none;
}

.footer-column p {
    color: #d1d5db;
    margin-bottom: 8px;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #374151;
    color: #9ca3af;
    font-size: 14px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-header {
        height: 80px;
    }

    .header-container {
        padding: 0 15px;
    }

    .logo-placeholder {
        min-width: 100px;
        height: 60px;
        font-size: 16px;
    }

    /* Hide navigation on mobile */
    .main-nav {
        display: none;
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background-color: white;
        border-bottom: 1px solid var(--border-color);
        padding: 20px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }

    .main-nav.active {
        display: flex;
        flex-direction: column;
    }

    .nav-list {
        flex-direction: column;
        gap: 10px;
        width: 100%;
    }

    .topic-btn {
        width: 100%;
        text-align: left;
        padding: 12px 16px;
    }

    /* Show burger menu on mobile */
    .burger-menu-btn {
        display: flex;
        order: -1;
    }

    .main-container {
        padding: 15px;
    }

    .body-section {
        height: 600px;
    }

    .content-wrapper {
        padding: 25px;
    }

    .content-wrapper h2 {
        font-size: 24px;
    }

    .content-wrapper p {
        font-size: 14px;
    }

    .bottom-section {
        height: auto;
        padding: 30px 20px;
    }

    .footer-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

@media (max-width: 480px) {
    .top-header {
        font-size: 11px;
        padding: 0 15px;
    }

    .main-header {
        height: 70px;
    }

    .logo-placeholder {
        min-width: 80px;
        height: 50px;
        font-size: 14px;
    }

    .main-container {
        padding: 10px;
    }

    .body-section {
        height: 550px;
        border-radius: 6px;
    }

    .content-wrapper {
        padding: 20px;
    }

    .content-wrapper h2 {
        font-size: 20px;
        margin-bottom: 15px;
    }

    .content-wrapper p {
        font-size: 13px;
    }

    .bottom-section {
        height: auto;
        padding: 25px 15px;
    }

    .footer-column h3 {
        font-size: 14px;
        margin-bottom: 10px;
    }

    .footer-bottom {
        font-size: 12px;
    }
}