.content-section {
    display: none;
    animation: fadeIn 0.4s ease;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: clamp(20px, 3vw, 32px);
    gap: clamp(12px, 2vw, 20px);
}

.search-bar {
    position: relative;
    flex: 1;
    max-width: 400px;
}

.search-bar input {
    width: 100%;
    padding: clamp(10px, 1.5vw, 12px) clamp(16px, 2.5vw, 20px);
    border-radius: 14px;
    border: 1px solid var(--white-15);
    font-size: clamp(0.75rem, 1.2vw, 0.85rem);
    font-weight: 600;
    transition: all 0.3s ease;
    backdrop-filter: blur(12px);
}

.dark-theme .search-bar input {
    background: var(--dark-primary-08);
    color: var(--dark-text);
    border-color: var(--dark-primary-20);
}

.light-theme .search-bar input {
    background: var(--light-primary-08);
    color: var(--light-text);
    border-color: var(--light-primary-20);
}

.search-bar input:focus {
    outline: none;
}

.dark-theme .search-bar input:focus {
    border-color: var(--dark-primary-40);
    box-shadow: 0 0 20px var(--dark-primary-20);
}

.light-theme .search-bar input:focus {
    border-color: var(--light-primary-40);
    box-shadow: 0 0 20px var(--light-primary-20);
}

.action-button {
    padding: clamp(10px, 1.5vw, 12px) clamp(20px, 3vw, 28px);
    border-radius: 14px;
    border: none;
    font-weight: 800;
    font-size: clamp(0.75rem, 1.2vw, 0.85rem);
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(12px);
}

.dark-theme .action-button {
    background: linear-gradient(135deg, var(--dark-primary), var(--dark-secondary));
    color: var(--white);
    box-shadow: 0 6px 20px var(--dark-primary-30);
}

.light-theme .action-button {
    background: linear-gradient(135deg, var(--light-primary), var(--light-secondary));
    color: var(--white);
    box-shadow: 0 6px 20px var(--light-primary-30);
}

.action-button:hover {
    transform: translateY(-2px);
}

.dark-theme .action-button:hover {
    box-shadow: 0 8px 24px var(--dark-primary-40);
}

.light-theme .action-button:hover {
    box-shadow: 0 8px 24px var(--light-primary-40);
}

.challenge-sidebar {
    position: fixed;
    right: -100%;
    top: 0;
    width: clamp(320px, 45vw, 480px);
    height: 100vh;
    z-index: 1001;
    backdrop-filter: blur(24px);
    border-left: 1px solid var(--white-15);
    transition: right 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    overflow-y: auto;
}

.dark-theme .challenge-sidebar {
    background: var(--sidebar-dark-bg);
    border-left-color: var(--dark-primary-25);
    box-shadow: -2px 0 24px var(--dark-primary-15);
}

.light-theme .challenge-sidebar {
    background: var(--sidebar-light-bg);
    border-left-color: var(--light-primary-25);
    box-shadow: -2px 0 24px var(--light-primary-15);
}

.challenge-sidebar.open {
    right: 0;
}

.sidebar-header-challenge {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: clamp(20px, 3vw, 28px);
    border-bottom: 1px solid var(--white-15);
    position: sticky;
    top: 0;
    z-index: 10;
    backdrop-filter: blur(24px);
}

.dark-theme .sidebar-header-challenge {
    background: var(--sidebar-dark-bg);
    border-bottom-color: var(--dark-primary-25);
}

.light-theme .sidebar-header-challenge {
    background: var(--sidebar-light-bg);
    border-bottom-color: var(--light-primary-25);
}

.sidebar-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 10px;
    transition: all 0.3s ease;
    font-size: 28px;
    line-height: 1;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.dark-theme .sidebar-close {
    color: var(--dark-text);
}

.light-theme .sidebar-close {
    color: var(--light-text);
}

.sidebar-close:hover {
    transform: rotate(90deg);
}

.dark-theme .sidebar-close:hover {
    background: var(--dark-primary-15);
}

.light-theme .sidebar-close:hover {
    background: var(--light-primary-15);
}

.sidebar-content {
    padding: clamp(20px, 3vw, 28px);
    display: flex;
    flex-direction: column;
    gap: clamp(24px, 3.5vw, 32px);
}

.challenge-description p {
    line-height: 1.6;
    opacity: 0.9;
}

.challenge-resources h4,
.flag-submission h4 {
    font-size: clamp(0.85rem, 1.3vw, 1rem);
    margin-bottom: clamp(12px, 2vw, 16px);
    font-weight: 800;
}

.resource-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.resource-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: clamp(10px, 1.5vw, 12px) clamp(14px, 2vw, 16px);
    border-radius: 12px;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 1px solid var(--white-15);
    backdrop-filter: blur(12px);
}

.dark-theme .resource-item {
    background: var(--dark-primary-08);
    color: var(--dark-text);
    border-color: var(--dark-primary-20);
}

.light-theme .resource-item {
    background: var(--light-primary-08);
    color: var(--light-text);
    border-color: var(--light-primary-20);
}

.resource-item:hover {
    transform: translateX(6px);
}

.dark-theme .resource-item:hover {
    background: var(--dark-primary-15);
    border-color: var(--dark-primary-30);
}

.light-theme .resource-item:hover {
    background: var(--light-primary-15);
    border-color: var(--light-primary-30);
}

.flag-input-group {
    display: flex;
    gap: 10px;
}

.flag-input-group input {
    flex: 1;
    padding: clamp(10px, 1.5vw, 12px) clamp(14px, 2vw, 16px);
    border-radius: 12px;
    border: 1px solid var(--white-15);
    font-size: clamp(0.75rem, 1.2vw, 0.85rem);
    font-weight: 600;
    transition: all 0.3s ease;
}

.dark-theme .flag-input-group input {
    background: var(--dark-primary-08);
    color: var(--dark-text);
    border-color: var(--dark-primary-20);
}

.light-theme .flag-input-group input {
    background: var(--light-primary-08);
    color: var(--light-text);
    border-color: var(--light-primary-20);
}

.flag-input-group input:focus {
    outline: none;
}

.dark-theme .flag-input-group input:focus {
    border-color: var(--dark-primary-40);
    box-shadow: 0 0 20px var(--dark-primary-20);
}

.light-theme .flag-input-group input:focus {
    border-color: var(--light-primary-40);
    box-shadow: 0 0 20px var(--light-primary-20);
}

.submit-flag-btn {
    padding: clamp(10px, 1.5vw, 12px) clamp(20px, 3vw, 24px);
    border-radius: 12px;
    border: none;
    font-weight: 800;
    font-size: clamp(0.75rem, 1.2vw, 0.85rem);
    cursor: pointer;
    transition: all 0.3s ease;
}

.dark-theme .submit-flag-btn {
    background: linear-gradient(135deg, var(--dark-primary), var(--dark-secondary));
    color: var(--white);
}

.light-theme .submit-flag-btn {
    background: linear-gradient(135deg, var(--light-primary), var(--light-secondary));
    color: var(--white);
}

.submit-flag-btn:hover {
    transform: translateY(-2px);
}

.dark-theme .submit-flag-btn:hover {
    box-shadow: 0 6px 20px var(--dark-primary-30);
}

.light-theme .submit-flag-btn:hover {
    box-shadow: 0 6px 20px var(--light-primary-30);
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: var(--black-70);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(8px);
}

.modal.show {
    display: flex;
}

.modal-content {
    width: clamp(300px, 90vw, 480px);
    border-radius: 20px;
    backdrop-filter: blur(24px);
    border: 1px solid var(--white-15);
    animation: modalSlideIn 0.3s ease;
}

.dark-theme .modal-content {
    background: var(--dropdown-dark-bg);
    border-color: var(--dark-primary-25);
    box-shadow: 0 20px 64px var(--black-40);
}

.light-theme .modal-content {
    background: var(--dropdown-light-bg);
    border-color: var(--light-primary-25);
    box-shadow: 0 20px 64px var(--black-15);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: clamp(20px, 3vw, 24px);
    border-bottom: 1px solid var(--white-15);
}

.dark-theme .modal-header {
    border-bottom-color: var(--dark-primary-25);
}

.light-theme .modal-header {
    border-bottom-color: var(--light-primary-25);
}

.modal-header h3 {
    font-size: clamp(1rem, 1.5vw, 1.2rem);
    font-weight: 900;
}

.modal-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 10px;
    transition: all 0.3s ease;
    font-size: 28px;
    line-height: 1;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.dark-theme .modal-close {
    color: var(--dark-text);
}

.light-theme .modal-close {
    color: var(--light-text);
}

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

.dark-theme .modal-close:hover {
    background: var(--dark-primary-15);
}

.light-theme .modal-close:hover {
    background: var(--light-primary-15);
}

.modal-body {
    padding: clamp(20px, 3vw, 24px);
}

.app-footer {
    position: fixed;
    bottom: 0;
    left: 220px;
    right: 0;
    height: 48px;
    z-index: 998;
    backdrop-filter: blur(24px);
    border-top: 1px solid var(--white-10);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.dark-theme .app-footer {
    background: var(--topbar-dark-bg);
    border-top-color: var(--dark-primary-25);
}

.light-theme .app-footer {
    background: var(--topbar-light-bg);
    border-top-color: var(--light-primary-25);
}

.footer-content {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: clamp(0.7rem, 1.1vw, 0.8rem);
    font-weight: 600;
}

.footer-text {
    opacity: 0.7;
}

.footer-separator {
    opacity: 0.4;
}

.footer-dev {
    opacity: 0.7;
}

.footer-dev a {
    text-decoration: none;
    font-weight: 800;
    transition: all 0.3s ease;
}

.dark-theme .footer-dev a {
    color: var(--dark-secondary);
}

.light-theme .footer-dev a {
    color: var(--light-primary);
}

.footer-dev a:hover {
    opacity: 1;
    text-decoration: underline;
}

@media (max-width: 1280px) {
    .app-footer {
        left: 0;
    }
}

@media (max-width: 768px) {
    .challenge-sidebar {
        width: 100vw;
    }
    
    .section-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .search-bar {
        max-width: 100%;
    }
    
    .app-footer {
        height: 40px;
    }
    
    .footer-content {
        font-size: clamp(0.65rem, 1vw, 0.75rem);
        gap: 8px;
    }
}

@media (max-width: 640px) {
    .footer-content {
        flex-direction: column;
        gap: 4px;
        text-align: center;
    }
    
    .footer-separator {
        display: none;
    }
}