:root {
    --bg: #07070d;
    --surface: rgba(255, 255, 255, 0.06);
    --border: rgba(255, 255, 255, 0.12);
    --text: #f3f3f6;
    --muted: #b4b4c3;
    --primary: #7c5cff;
    --primary-2: #22d3ee;
    --header-bg: rgba(7, 7, 13, 0.72);
    --shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
    --radius: 18px;

    color-scheme: dark;
}

.page.light {
    --bg: #f6f7fb;
    --surface: rgba(15, 23, 42, 0.06);
    --border: rgba(15, 23, 42, 0.12);
    --text: #0f172a;
    --muted: #46536b;
    --primary: #6d28d9;
    --primary-2: #0891b2;
    --header-bg: rgba(246, 247, 251, 0.82);
    --shadow: 0 20px 60px rgba(15, 23, 42, 0.12);

    color-scheme: light;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: #07070d;
    color: var(--text);
    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Arial,
        sans-serif;
    line-height: 1.6;
}

button,
input,
select {
    font: inherit;
}

.page {
    min-height: 100vh;
    background:
        radial-gradient(circle at top left, rgba(124, 92, 255, 0.18), transparent 30%),
        radial-gradient(circle at top right, rgba(34, 211, 238, 0.12), transparent 28%),
        var(--bg);
    color: var(--text);
}

.page.light {
    background:
        radial-gradient(circle at top left, rgba(124, 92, 255, 0.14), transparent 30%),
        radial-gradient(circle at top right, rgba(34, 211, 238, 0.12), transparent 28%),
        var(--bg);
}

.container {
    width: min(1100px, calc(100% - 32px));
    margin-inline: auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 40;
    backdrop-filter: blur(12px);
    background: var(--header-bg);
    border-bottom: 1px solid var(--border);
}

.nav {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 14px 0;
}

.brand {
    border: none;
    background: none;
    color: var(--text);
    font-weight: 800;
    letter-spacing: 0.02em;
    cursor: pointer;
    padding: 8px 0;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    border: 1px solid transparent;
    background: none;
    color: var(--muted);
    padding: 9px 12px;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 700;
}

.nav-link:hover {
    color: var(--text);
    background: var(--surface);
}

.nav-link.active {
    color: var(--text);
    background: var(--surface);
    border-color: var(--border);
}

.nav-controls {
    display: flex;
    align-items: center;
    gap: 8px;
}

.icon-button {
    width: 42px;
    height: 42px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
}

.icon-button:hover,
.button:hover,
.page-card:hover,
.contact-item:hover,
.favorite-button:hover,
.filter-button:hover,
.testimonial-button:hover,
.modal-close:hover {
    transform: translateY(-1px);
    border-color: var(--primary);
}

.menu-toggle {
    display: none;
}

.main {
    padding: 28px 0 70px;
}

.app-page {
    display: none;
}

.app-page.active {
    display: block;
    animation: fade-in 0.25s ease both;
}

.hidden {
    display: none !important;
}

.page-header {
    margin-bottom: 22px;
}

.page-header h2 {
    margin: 0 0 8px;
    font-size: clamp(1.7rem, 3vw, 2.5rem);
}

.section-text {
    margin: 0;
    color: var(--muted);
    max-width: 760px;
}

.panel {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 24px;
    padding: 26px;
}

.home-hero {
    max-width: 900px;
}

.crumb {
    margin: 0 0 10px;
    color: var(--primary-2);
    font-weight: 800;
}

h1 {
    margin: 0 0 10px;
    font-size: clamp(2.3rem, 6vw, 4.2rem);
    line-height: 1.05;
}

.subtitle {
    margin: 0;
    font-size: clamp(1.05rem, 2.5vw, 1.5rem);
    font-weight: 650;
}

.bio {
    max-width: 760px;
    color: var(--muted);
    margin-top: 16px;
}

.actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 24px;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 18px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    text-decoration: none;
    font-weight: 700;
    cursor: pointer;
}

.button.primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    color: #06060a;
    border: none;
}

.button.small {
    padding: 9px 12px;
    font-size: 0.95rem;
}

.button.outline {
    background: transparent;
}

.stats {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 28px;
}

.stat {
    padding: 14px 18px;
    border-radius: 18px;
    border: 1px solid var(--border);
    background: var(--surface);
}

.stat strong {
    display: block;
    font-size: 1.35rem;
    line-height: 1.2;
}

.stat span {
    color: var(--muted);
    font-size: 0.92rem;
}

.home-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
    margin-top: 24px;
}

.page-card {
    text-align: left;
    padding: 18px;
    border-radius: 22px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
    display: grid;
    gap: 8px;
}

.card-icon {
    font-size: 1.4rem;
}

.page-card-title {
    font-weight: 800;
}

.page-card-body {
    color: var(--muted);
    font-size: 0.95rem;
}

.section {
    padding: 36px 0 10px;
}

.section h2 {
    margin: 0 0 10px;
    font-size: clamp(1.7rem, 3vw, 2.5rem);
}

.highlight-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.highlight-card {
    padding: 22px;
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: var(--radius);
}

.highlight-card:hover,
.project-card:hover,
.page-card:hover,
.contact-item:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
}

.icon {
    display: inline-block;
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.highlight-card h3 {
    margin: 0 0 10px;
}

.highlight-card p {
    margin: 0;
    color: var(--muted);
}

.accordion-list {
    display: grid;
    gap: 14px;
}

.accordion {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 20px;
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    padding: 18px;
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    font-weight: 800;
    text-align: left;
}

summary.accordion-header {
    list-style: none;
}

summary.accordion-header::-webkit-details-marker {
    display: none;
}

.chevron {
    color: var(--muted);
    transform: rotate(-90deg);
    transition: transform 0.2s ease;
}

.accordion.open .chevron,
details[open].accordion .chevron {
    transform: rotate(0deg);
}

.accordion-body {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.25s ease;
}

.accordion.open .accordion-body,
details[open].accordion .accordion-body {
    grid-template-rows: 1fr;
}

.accordion-inner {
    overflow: hidden;
}

.accordion-content {
    padding: 0 18px 18px;
}

.chips {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.chip {
    padding: 10px 14px;
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 999px;
    color: var(--text);
}

.toolbar {
    display: grid;
    gap: 14px;
    margin-bottom: 22px;
}

.toolbar-row {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: center;
}

.search-input {
    flex: 1 1 340px;
    padding: 13px 15px;
    border-radius: 14px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    outline: none;
}

.sort-select {
    min-width: 180px;
    padding: 13px 15px;
    border-radius: 14px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    outline: none;
}

.search-input::placeholder {
    color: var(--muted);
}

.search-input:focus-visible,
.sort-select:focus-visible {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(124, 92, 255, 0.22);
}

.filters {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-button {
    padding: 9px 13px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--muted);
    font-weight: 700;
    cursor: pointer;
}

.filter-button.active {
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    color: #06060a;
    border-color: transparent;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.card {
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: var(--radius);
    padding: 22px;
}

.project-banner {
    position: relative;
    display: grid;
    place-items: center;
    height: 110px;
    border-radius: 14px;
    border: 1px solid var(--border);
    margin-bottom: 14px;
    overflow: hidden;
}

.project-icon {
    font-size: 2rem;
    filter: drop-shadow(0 8px 18px rgba(0, 0, 0, 0.22));
}

.favorite-button {
    position: absolute;
    top: 10px;
    right: 10px;
    width: 36px;
    height: 36px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
}

.favorite-button.active {
    color: #ff6b81;
    border-color: rgba(255, 107, 129, 0.45);
}

.card-top {
    margin-bottom: 12px;
}

.badge {
    display: inline-flex;
    padding: 6px 10px;
    border-radius: 999px;
    font-size: 0.85rem;
    font-weight: 800;
}

.badge.prediction-models {
    background: rgba(34, 211, 238, 0.14);
    color: #22d3ee;
    border: 1px solid rgba(34, 211, 238, 0.28);
}

.badge.transformers {
    background: rgba(124, 92, 255, 0.14);
    color: #a78bfa;
    border: 1px solid rgba(124, 92, 255, 0.28);
}

.badge.fine-tuning {
    background: rgba(244, 114, 182, 0.14);
    color: #f472b6;
    border: 1px solid rgba(244, 114, 182, 0.28);
}

.badge.graph-rag {
    background: rgba(52, 211, 153, 0.14);
    color: #34d399;
    border: 1px solid rgba(52, 211, 153, 0.28);
}

.badge.multi-agent-system {
    background: rgba(255, 145, 77, 0.14);
    color: #ff914d;
    border: 1px solid rgba(255, 145, 77, 0.28);
}

.badge.data-science {
    background: rgba(96, 165, 250, 0.14);
    color: #60a5fa;
    border: 1px solid rgba(96, 165, 250, 0.28);
}

.project-banner.prediction-models {
    background: linear-gradient(135deg, rgba(34, 211, 238, 0.22), rgba(124, 92, 255, 0.18));
}

.project-banner.transformers {
    background: linear-gradient(135deg, rgba(124, 92, 255, 0.24), rgba(167, 139, 250, 0.18));
}

.project-banner.fine-tuning {
    background: linear-gradient(135deg, rgba(244, 114, 182, 0.22), rgba(124, 92, 255, 0.18));
}

.project-banner.graph-rag {
    background: linear-gradient(135deg, rgba(52, 211, 153, 0.22), rgba(34, 211, 238, 0.18));
}

.project-banner.multi-agent-system {
    background: linear-gradient(135deg, rgba(255, 145, 77, 0.22), rgba(124, 92, 255, 0.18));
}

.project-banner.data-science {
    background: linear-gradient(135deg, rgba(96, 165, 250, 0.22), rgba(34, 211, 238, 0.18));
}

.tech-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 12px 0;
}

.tech-chip {
    padding: 6px 9px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--muted);
    font-size: 0.85rem;
    font-weight: 600;
}

.card-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 16px;
}

.modal-root {
    position: fixed;
    inset: 0;
    z-index: 60;
    display: grid;
    place-items: center;
    padding: 20px;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.62);
    backdrop-filter: blur(4px);
}

.modal {
    position: relative;
    z-index: 1;
    width: min(700px, 100%);
    max-height: min(80vh, 900px);
    overflow: auto;
    padding: 26px;
    border-radius: 24px;
    border: 1px solid var(--border);
    background: var(--bg);
    box-shadow: var(--shadow);
}

.modal-close {
    position: absolute;
    top: 14px;
    right: 14px;
    width: 40px;
    height: 40px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    font-size: 1.4rem;
    line-height: 1;
    cursor: pointer;
}

.modal-details {
    color: var(--muted);
}

.highlight-list {
    margin: 0 0 18px;
    padding-left: 20px;
    color: var(--muted);
}

.highlight-list li {
    margin: 8px 0;
}

.modal-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.journey-summary {
    display: grid;
    gap: 2px;
}

.journey-period {
    color: var(--primary-2);
    font-size: 0.92rem;
    font-weight: 800;
}

.journey-title {
    font-weight: 800;
}

.journey-description {
    margin: 0;
    color: var(--muted);
}

.testimonial-card {
    margin: 0;
    padding: 28px;
    border: 1px solid var(--border);
    background: var(--surface);
    border-radius: 24px;
}

.testimonial-card p {
    margin: 0 0 18px;
    font-size: 1.05rem;
}

.testimonial-meta {
    display: grid;
    gap: 2px;
    color: var(--muted);
}

.testimonial-controls {
    display: flex;
    gap: 10px;
    margin-top: 18px;
}

.testimonial-button {
    width: 44px;
    height: 44px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    border-radius: 18px;
    border: 1px solid var(--border);
    background: var(--bg);
    color: var(--text);
    text-decoration: none;
}

.contact-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.contact-text small {
    color: var(--muted);
}

.footer {
    border-top: 1px solid var(--border);
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    padding: 20px 0;
    color: var(--muted);
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.footer-link {
    border: none;
    background: none;
    color: var(--muted);
    cursor: pointer;
    padding: 6px 8px;
    border-radius: 8px;
}

.footer-link:hover {
    color: var(--text);
    background: var(--surface);
}

.back-to-top {
    position: fixed;
    right: 14px;
    bottom: 14px;
    z-index: 35;
    width: 44px;
    height: 44px;
    display: grid;
    place-items: center;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--text);
    text-decoration: none;
    box-shadow: var(--shadow);
}

:focus-visible {
    outline: 2px solid var(--primary-2);
    outline-offset: 2px;
}

@keyframes fade-in {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@media (max-width: 900px) {
    .home-grid,
    .highlight-grid,
    .projects-grid,
    .contact-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 760px) {
    .menu-toggle {
        display: inline-flex;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
        padding: 14px 16px 18px;
        background: var(--header-bg);
        border-bottom: 1px solid var(--border);
        backdrop-filter: blur(12px);
    }

    .nav-links.open {
        display: flex;
    }

    .nav-link {
        width: 100%;
        text-align: left;
    }

    .home-grid,
    .highlight-grid,
    .projects-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .toolbar-row {
        flex-direction: column;
        align-items: stretch;
    }

    .sort-select {
        width: 100%;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }

    html {
        scroll-behavior: auto;
    }
}