:root {
    /* Updated color palette */
    --color-neutral-light: #EFEAE1;
    --color-neutral-white: #FFFFFF;
    --color-accent-red: #C03435;
    --color-primary-navy: #3D5073;
    --color-brand-red: #EA2528;
    --color-brand-blue: #3176BA;
    --color-neutral-dark: #2E2D29;

    /* Derived colors for better UX */
    --background-primary: var(--color-neutral-white);
    --background-secondary: var(--color-neutral-light);
    --background-subtle: #F8F6F2;
    --text-primary: var(--color-neutral-dark);
    --text-secondary: #5A5A54;
    --text-muted: #8B8B85;
    --border-light: #DDD8CF;
    --border-medium: #C7C1B6;

    /* Interactive states */
    --hover-overlay: rgba(61, 80, 115, 0.05);
    --active-overlay: rgba(49, 118, 186, 0.1);
    --focus-ring: rgba(49, 118, 186, 0.3);

    /* Shadows with warm undertones */
    --shadow-sm: 0 2px 4px rgba(46, 45, 41, 0.08);
    --shadow-md: 0 6px 12px rgba(46, 45, 41, 0.12);
    --shadow-lg: 0 12px 24px rgba(46, 45, 41, 0.16);
    --shadow-xl: 0 20px 40px rgba(46, 45, 41, 0.2);

    /* Smooth transitions */
    --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-standard: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Lato', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--background-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
}

/* Improved header with gradient using new colors */
.header {
    background: linear-gradient(135deg, var(--color-primary-navy), var(--color-brand-blue), var(--color-brand-red));
    color: white;
    padding: 4rem 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.08'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
    opacity: 0.6;
    z-index: 0;
}

.header-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
    padding: 0 2rem;
}

.header  h2 {
    font-family: 'Montserrat', sans-serif;
    font-size: clamp(2.5rem, 3.5rem, 4.5rem);
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header p {
    font-size: clamp(1rem, 3vw, 1.25rem);
    opacity: 0.95;
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

/* Enhanced controls with better accessibility */
.controls {
    background: var(--background-primary);
    border-bottom: 1px solid var(--border-light);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-sm);
}

.controls-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.view-toggle {
    display: flex;
    background: var(--background-subtle);
    border-radius: 12px;
    padding: 4px;
    border: 1px solid var(--border-light);
    box-shadow: inset 0 1px 3px rgba(46, 45, 41, 0.05);
}

.toggle-btn {
    padding: 0.75rem 1.5rem;
    border: none;
    background: transparent;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    position: relative;
    white-space: nowrap;
}

.toggle-btn:hover {
    color: var(--color-brand-blue);
    background: var(--hover-overlay);
}

.toggle-btn:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.toggle-btn.active {
    background: var(--background-primary);
    color: var(--color-primary-navy);
    box-shadow: var(--shadow-sm);
    font-weight: 700;
}

.year-filter {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    flex-wrap: wrap;
}

.year-filter label {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.875rem;
    white-space: nowrap;
}

/* Enhanced dropdown design */
.dropdown-container {
    position: relative;
    display: inline-block;
}

.filter-select {
    padding: 0.75rem 1.25rem;
    border: 1px solid var(--border-medium);
    border-radius: 8px;
    background: var(--background-primary);
    font-size: 0.875rem;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition-fast);
    min-width: 160px;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%233D5073' d='M10.293 3.293L6 7.586 1.707 3.293A1 1 0 00.293 4.707l5 5a1 1 0 001.414 0l5-5a1 1 0 10-1.414-1.414z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    padding-right: 2.5rem;
}

.filter-select:hover {
    border-color: var(--color-brand-blue);
    box-shadow: 0 0 0 3px rgba(49, 118, 186, 0.1);
}

.filter-select:focus {
    outline: none;
    border-color: var(--color-brand-blue);
    box-shadow: 0 0 0 3px var(--focus-ring);
}

.help-btn {
    background: var(--color-brand-blue);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    transition: var(--transition-standard);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow-sm);
    white-space: nowrap;
}

.help-btn:hover {
    background: var(--color-primary-navy);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.help-btn:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.help-btn:active {
    transform: translateY(0);
}

/* Timeline container */
.timeline-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

/* Enhanced compact view */
.compact-timeline {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.compact-year-card {
    background: var(--background-primary);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-standard);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.compact-year-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-brand-blue), var(--color-brand-red));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-slow);
}

.compact-year-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-brand-blue);
}

.compact-year-card:hover::before {
    transform: scaleX(1);
}

.compact-year-card:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.compact-year-card.active {
    border-color: var(--color-brand-blue);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--background-primary), var(--background-subtle));
}

.compact-year-card.active::before {
    transform: scaleX(1);
}

.year-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.year-number {
    font-family: 'Montserrat', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary-navy);
}

.project-count {
    background: var(--background-subtle);
    color: var(--text-secondary);
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border: 1px solid var(--border-light);
}

.year-summary {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.tech-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag-small {
    background: var(--background-subtle);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--border-light);
}

/* Traditional timeline with improved styling */
.traditional-timeline {
    display: none;
    position: relative;
    padding-left: 3rem;
}

.timeline-line {
    position: absolute;
    left: 1.5rem;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(to bottom, var(--color-primary-navy), var(--color-brand-blue), var(--color-brand-red));
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 4rem;
    padding-left: 3rem;
}

.timeline-marker {
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 1.5rem;
    height: 1.5rem;
    background: var(--color-primary-navy);
    border: 4px solid var(--background-primary);
    border-radius: 50%;
    box-shadow: var(--shadow-md);
    transition: var(--transition-standard);
    cursor: pointer;
}

.timeline-marker:hover {
    transform: scale(1.1);
    background: var(--color-brand-blue);
}

.timeline-marker:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.timeline-marker.active {
    background: var(--color-brand-blue);
    box-shadow: 0 0 0 5px var(--active-overlay), var(--shadow-md);
}

.timeline-content {
    background: var(--background-primary);
    border-radius: 16px;
    padding: 2rem;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-standard);
}

.timeline-content:hover {
    box-shadow: var(--shadow-lg);
    transform: translateX(8px);
}

/* Enhanced projects section */
.projects-section {
    margin-top: 2rem;
    display: none;
    animation: slideUp 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.projects-section.visible {
    display: block;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.projects-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-light);
}

.projects-section h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-primary-navy);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.project-card {
    background: var(--background-primary);
    border-radius: 12px;
    padding: 2rem;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-standard);
    position: relative;
    overflow: hidden;
    will-change: transform;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-brand-red), var(--color-brand-blue));
    transform: scaleX(0);
    transform-origin: left;
    transition: var(--transition-slow);
}

.project-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.project-card:hover::before {
    transform: scaleX(1);
}

.project-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary-navy);
    margin-bottom: 0.75rem;
    line-height: 1.3;
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.25rem;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-tag {
    background: var(--background-subtle);
    color: var(--text-secondary);
    padding: 0.4rem 0.8rem;
    border-radius: 16px;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--border-light);
}

/* Enhanced loading and error states */
.loading,
.no-projects {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--text-muted);
    font-style: italic;
    background: var(--background-subtle);
    border-radius: 12px;
    margin: 1rem 0;
}

.loading::after {
    content: '';
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-medium);
    border-top-color: var(--color-brand-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-left: 0.75rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Improved modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(46, 45, 41, 0.7);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(8px);
    animation: fadeIn 0.3s ease-out;
}

.modal-overlay.visible {
    display: flex;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal {
    background: var(--background-primary);
    border-radius: 20px;
    padding: 2.5rem;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    animation: modalSlideIn 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
    border: 1px solid var(--border-light);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-30px) scale(0.95);
    }

    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-light);
}

.modal-title {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-primary-navy);
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-fast);
    padding: 0.5rem;
    border-radius: 50%;
    width: 2.5rem;
    height: 2.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.close-btn:hover {
    color: var(--color-brand-red);
    background: var(--hover-overlay);
}

.close-btn:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.help-section {
    margin-bottom: 2rem;
}

.help-section:last-child {
    margin-bottom: 0;
}

.help-section h3 {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--color-primary-navy);
}

.help-section p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0.5rem;
}

.help-section p:last-child {
    margin-bottom: 0;
}

/* Enhanced explore buttons */
.explore-btn,
.show-less-btn {
    grid-column: 1 / -1;
    justify-self: center;
    padding: 1rem 2rem;
    background: var(--color-brand-blue);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-standard);
    margin: 2rem 0;
    font-family: 'Montserrat', sans-serif;
    box-shadow: var(--shadow-md);
    font-size: 0.95rem;
}

.show-less-btn {
    background: var(--text-secondary);
}

.explore-btn:hover,
.show-less-btn:hover {
    background: var(--color-primary-navy);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.explore-btn:focus,
.show-less-btn:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

.explore-btn:active,
.show-less-btn:active {
    transform: translateY(0);
}

/* Close button for projects section */
.projects-close-btn {
    background: var(--color-brand-red);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    transition: var(--transition-standard);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow-sm);
}

.projects-close-btn:hover {
    background: var(--color-accent-red);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.projects-close-btn:focus {
    outline: 2px solid var(--color-brand-red);
    outline-offset: 2px;
}

.projects-close-btn:active {
    transform: translateY(0);
}

/* Error message styling */
.error-message {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--color-brand-red);
    color: white;
    padding: 2rem;
    border-radius: 12px;
    z-index: 10000;
    text-align: center;
    box-shadow: var(--shadow-xl);
    max-width: 400px;
    width: 90%;
}

.error-message h3 {
    font-family: 'Montserrat', sans-serif;
    margin-bottom: 0.5rem;
}

/* Responsive design improvements */
@media (max-width: 768px) {
    .header {
        padding: 2.5rem 0;
    }

    .controls-content {
        flex-direction: column;
        align-items: stretch;
        gap: 1.5rem;
    }

    .view-toggle {
        justify-content: center;
    }

    .year-filter {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .timeline-container {
        padding: 2rem 1rem;
    }

    .compact-timeline {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .projects-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .traditional-timeline {
        padding-left: 2rem;
    }

    .timeline-item {
        padding-left: 2.5rem;
    }

    .timeline-line {
        left: 1rem;
    }

    .timeline-marker {
        left: 0.25rem;
    }

    .compact-year-card,
    .project-card,
    .timeline-content {
        padding: 1.5rem;
    }

    .modal {
        padding: 2rem;
        border-radius: 16px;
    }

    .projects-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
}

@media (max-width: 480px) {

    .header-content,
    .controls-content,
    .timeline-container {
        padding-left: 1rem;
        padding-right: 1rem;
    }

    .year-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .project-count {
        align-self: flex-start;
    }
}

/* Accessibility improvements */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border-light: #999;
        --border-medium: #666;
        --text-secondary: #333;
        --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
        --shadow-md: 0 6px 12px rgba(0, 0, 0, 0.4);
        --shadow-lg: 0 12px 24px rgba(0, 0, 0, 0.5);
    }
}

/* Focus styles for keyboard navigation */
.compact-year-card:focus,
.timeline-marker:focus,
.toggle-btn:focus,
.filter-select:focus,
.help-btn:focus,
.close-btn:focus,
.explore-btn:focus,
.show-less-btn:focus,
.projects-close-btn:focus {
    outline: 2px solid var(--color-brand-blue);
    outline-offset: 2px;
}

/* Skip link for accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-primary-navy);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
}

.skip-link:focus {
    top: 6px;
}

/* Loading spinner improvements */
@media (prefers-reduced-motion: no-preference) {
    .loading::after {
        animation: spin 1s linear infinite;
    }
}

@media (prefers-reduced-motion: reduce) {
    .loading::after {
        animation: none;
        border-top-color: var(--color-brand-blue);
    }
}

/* Performance optimizations */
.safari-only-fix {
    transform: translateZ(0);
}