:root {
    --site-blue: rgb(0, 86, 150);
    --site-yellow: rgb(255, 193, 7);
    --dark-text: rgb(40, 40, 40);
    --bg-color: #f2f0ea;
    --surface-color: #fdfcf9;
    --surface-elevated: #f8f5ee;
    --text-color: var(--dark-text);
    --text-color-light: #4f4f4f;
    --border-color: #c8d4df;
    --accent-color: var(--site-blue);
    --accent-soft: color-mix(in srgb, var(--site-yellow) 28%, #ffffff);
    --header-bg: rgba(247, 243, 235, 0.92);
    --header-line-color: var(--accent-color);
    --footer-bg: #ece7dd;
    --bubble-bg: var(--site-blue);
    --bubble-text: #ffffff;
    --link-color: var(--site-blue);
    --search-bg: #ffffff;
    --search-text: var(--dark-text);
    --text-on-accent: #ffffff;
    --back-to-top-bg: var(--site-blue);
    --back-to-top-text: #ffffff;
    --shadow-soft: 0 12px 28px rgba(24, 37, 52, 0.09);
    --shadow-card: 0 18px 40px rgba(24, 37, 52, 0.14);
}

html.dark-mode {
    --bg-color: #131c24;
    --surface-color: #1b2732;
    --surface-elevated: #24313d;
    --text-color: #eaf0f5;
    --text-color-light: #b8c4cf;
    --border-color: #334454;
    --accent-color: var(--site-blue);
    --accent-soft: color-mix(in srgb, var(--site-yellow) 24%, transparent);
    --header-bg: rgba(16, 25, 33, 0.92);
    --header-line-color: var(--accent-color);
    --footer-bg: #101922;
    --bubble-bg: var(--site-yellow);
    --bubble-text: var(--dark-text);
    --link-color: color-mix(in srgb, var(--site-yellow) 72%, #ffffff);
    --search-bg: #20303c;
    --search-text: #eaf0f5;
    --text-on-accent: #ffffff;
    --back-to-top-bg: var(--site-blue);
    --back-to-top-text: #ffffff;
    --shadow-soft: 0 16px 36px rgba(0, 0, 0, 0.35);
    --shadow-card: 0 18px 40px rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 86px;
}

body {
    font-family: 'Source Sans 3', 'Segoe UI', sans-serif;
    background:
        radial-gradient(circle at 14% 8%, rgba(0, 86, 150, 0.13), transparent 33%),
        radial-gradient(circle at 88% 10%, rgba(27, 41, 56, 0.08), transparent 31%),
        linear-gradient(180deg, #f9f6f0 0%, var(--bg-color) 28%, var(--bg-color) 100%);
    color: var(--text-color);
    line-height: 1.72;
    transition: background-color 0.35s, color 0.35s;
}

html.dark-mode body {
    background:
    radial-gradient(circle at 8% 8%, rgba(0, 86, 150, 0.26), transparent 32%),
    radial-gradient(circle at 90% 12%, rgba(255, 193, 7, 0.16), transparent 30%),
        linear-gradient(180deg, #0f1720 0%, var(--bg-color) 34%, var(--bg-color) 100%);
}

main {
    max-width: 1040px;
    margin: 0 auto;
    padding: 0 24px;
    min-height: 70vh;
}

a {
    color: var(--link-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

p {
    margin-bottom: 1.15rem;
    color: var(--text-color-light);
    font-size: 1.06rem;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Cormorant Garamond', Georgia, serif;
    color: var(--text-color);
    margin-bottom: 0.9rem;
    letter-spacing: 0.015em;
}

ul, ol {
    margin-left: 20px;
    margin-bottom: 1rem;
    color: var(--text-color-light);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px max(20px, calc((100vw - 1100px) / 2));
    background-color: var(--header-bg);
    border-bottom: none;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    transition: background-color 0.3s, border-color 0.3s;
}

header::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: 2px;
    background-color: var(--header-line-color);
    pointer-events: none;
}

.logo a {
    font-family: 'Cormorant Garamond', Georgia, serif;
    font-size: 2.15rem;
    font-weight: 700;
    color: var(--text-color);
    text-decoration: none;
    flex-shrink: 0;
    transition: color 0.25s;
}

.logo a:hover {
    text-decoration: none;
    color: var(--accent-color);
}

.top-nav {
    display: flex;
    align-items: center;
    gap: 26px;
    margin-left: auto;
    margin-right: 18px;
}

.menu-toggle {
    display: none;
    width: 36px;
    height: 36px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: transparent;
    color: var(--text-color);
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    transition: border-color 0.2s ease, background-color 0.2s ease;
}

.menu-toggle:hover {
    border-color: var(--accent-color);
}

.menu-toggle span {
    width: 16px;
    height: 2px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: transform 0.24s ease, opacity 0.24s ease;
}

body.nav-open .menu-toggle {
    border-color: var(--accent-color);
    background-color: color-mix(in srgb, var(--accent-soft) 55%, transparent);
}

body.nav-open .menu-toggle span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

body.nav-open .menu-toggle span:nth-child(2) {
    opacity: 0;
}

body.nav-open .menu-toggle span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

.top-nav a {
    font-family: 'Source Sans 3', sans-serif;
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.09em;
    line-height: 1.1;
    text-transform: uppercase;
    color: var(--text-color-light);
    padding: 6px 0;
    display: inline-flex;
    align-items: center;
    border-bottom: 2px solid transparent;
    transition: color 0.25s, border-color 0.25s;
}

.top-nav a:hover {
    color: var(--text-color);
    border-bottom-color: transparent;
    text-decoration: none;
}

.top-nav a.active,
.top-nav a[aria-current='page'] {
    color: var(--accent-color);
    border-bottom-color: transparent;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 14px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.15s ease-in-out, visibility 0s 0.15s;
}

body.js-loaded .header-controls {
    opacity: 1;
    visibility: visible;
    transition: opacity 0.15s ease-in-out;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box input {
    background-color: var(--search-bg);
    color: var(--search-text);
    border: 1px solid var(--border-color);
    border-radius: 999px;
    padding: 8px 14px 8px 32px;
    font-size: 0.9rem;
    width: 190px;
    transition: width 0.3s, border-color 0.3s, box-shadow 0.3s;
}

.search-box input:focus {
    width: 235px;
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent-color) 22%, transparent);
}

.search-box i.fa-search {
    position: absolute;
    left: 11px;
    color: var(--text-color-light);
    font-size: 0.85rem;
}

#search-results {
    display: none;
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    width: 300px;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    box-shadow: var(--shadow-soft);
    z-index: 1100;
    max-height: 320px;
    overflow-y: auto;
}

.search-result-item {
    display: block;
    padding: 10px 15px;
    color: var(--text-color-light);
    text-decoration: none;
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border-color);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item:hover {
    background-color: var(--surface-elevated);
    color: var(--text-color);
    text-decoration: none;
}

.search-result-item strong {
    color: var(--text-color);
}

.search-no-result {
    display: block;
    padding: 10px 15px;
    color: var(--text-color-light);
    font-size: 0.9rem;
    text-align: center;
}

#theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    border-radius: 999px;
    width: 36px;
    height: 36px;
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.25s, transform 0.2s;
}

#theme-toggle:hover {
    border-color: var(--accent-color);
    transform: translateY(-1px);
}

#theme-toggle .icon-sun {
    display: none;
}

#theme-toggle .icon-moon {
    display: inline-block;
}

html.dark-mode #theme-toggle .icon-sun {
    display: inline-block;
}

html.dark-mode #theme-toggle .icon-moon {
    display: none;
}

.section {
    padding: 66px 0 48px;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.45s ease-in-out, transform 0.45s ease-in-out;
}

body.js-loaded .section {
    opacity: 1;
    transform: translateY(0);
}

#home {
    padding-top: 48px;
}

.section-title {
    font-size: clamp(2.3rem, 2.9vw, 3.05rem);
    text-align: center;
    margin-bottom: 24px;
    line-height: 1.12;
}

.section-subtitle {
    font-size: clamp(1.65rem, 2.15vw, 2.05rem);
    color: var(--text-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    margin-top: 40px;
    margin-bottom: 22px;
}

.hero {
    text-align: center;
    padding: 20px 0 22px;
    animation: gentle-reveal 0.8s ease both;
}

.hero h1 {
    font-size: clamp(2.5rem, 4vw, 3.5rem);
    margin-bottom: 2px;
}

.hero .subtitle {
    font-size: clamp(1.08rem, 1.6vw, 1.24rem);
    color: var(--text-color-light);
    max-width: 740px;
    margin: 0 auto;
}

.divider {
    display: none;
}

.profile-section {
    padding: 24px 0;
}

.profile-container {
    display: flex;
    gap: 32px;
}

#home .profile-container {
    flex-direction: column;
    align-items: center;
    gap: 22px;
}

.profile-column-left {
    flex-basis: 270px;
    min-width: 270px;
}

#home .profile-column-left {
    flex-basis: auto;
    min-width: 0;
    width: min(100%, 290px);
}

.profile-column-right {
    flex: 1;
    background: transparent;
    border: none;
    border-radius: 0;
    padding: 6px 0;
    box-shadow: none;
}

#home .profile-column-right {
    width: min(100%, 770px);
}

.profile-image-wrapper {
    position: relative;
    border-radius: 0;
    padding: 0;
    background: none;
    border: none;
    box-shadow: none;
}

.profile-image-wrapper::before {
    content: '';
    position: absolute;
    inset: 10px 8px auto 8px;
    height: 74%;
    border-radius: 999px;
    background: radial-gradient(circle, color-mix(in srgb, var(--accent-color) 28%, transparent), transparent 70%);
    filter: blur(12px);
    z-index: 0;
}

.profile-photo {
    position: relative;
    z-index: 1;
    width: 100%;
    height: auto;
    border-radius: 0;
    box-shadow: none;
}

#home .profile-column-right p {
    font-size: 1.05rem;
}

#home .profile-column-right a {
    font-weight: 600;
}

.status-bubble {
    width: 16px;
    height: 16px;
    background-color: var(--accent-color);
    border-radius: 50%;
    position: absolute;
    bottom: 12px;
    left: 14px;
    border: 2px solid var(--surface-color);
    animation: pulse 1.8s infinite;
    z-index: 3;
}

@keyframes pulse {
    0% {
        transform: scale(0.95);
        box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent-color) 65%, transparent);
    }
    70% {
        transform: scale(1);
        box-shadow: 0 0 0 10px color-mix(in srgb, var(--accent-color) 0%, transparent);
    }
    100% {
        transform: scale(0.95);
        box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent-color) 0%, transparent);
    }
}

.collab-bubble {
    position: absolute;
    bottom: 38px;
    left: 12px;
    background-color: var(--bubble-bg);
    color: var(--bubble-text);
    padding: 9px 12px;
    border-radius: 8px;
    font-size: 0.78rem;
    font-weight: 700;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s, transform 0.3s;
    white-space: nowrap;
    z-index: 2;
}

.profile-image-wrapper:hover .collab-bubble {
    opacity: 1;
    transform: translateY(0);
}

.collab-bubble::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 8px;
    border-width: 8px 8px 0 8px;
    border-style: solid;
    border-color: var(--bubble-bg) transparent transparent transparent;
}

.paper {
    margin-bottom: 18px;
}

.paper-content {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 6px 0 14px;
    border-radius: 0;
    border: none;
    background: transparent;
    box-shadow: none;
    transition: none;
}

.paper-content:hover {
    transform: none;
    box-shadow: none;
}

.paper-icon {
    display: none;
}

.paper-icon i {
    font-size: 1rem;
    color: var(--accent-color);
}

.paper-details {
    display: flex;
    flex-direction: column;
}

.paper-citation {
    font-size: 1.03rem;
    color: var(--text-color);
    line-height: 1.55;
    margin-bottom: 2px;
}

.paper-actions {
    display: flex;
    gap: 8px;
    margin-top: 0;
    flex-wrap: wrap;
}

.btn-abstract,
.btn-doi,
.btn-code {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 11px;
    font-size: 0.77rem;
    font-weight: 700;
    border-radius: 7px;
    cursor: pointer;
    transition: all 0.25s ease;
    text-decoration: none;
}

.btn-abstract {
    background-color: var(--accent-soft);
    color: var(--text-color);
    border: 1px solid color-mix(in srgb, var(--accent-color) 35%, transparent);
}

.btn-abstract:hover {
    background-color: var(--accent-color);
    color: var(--text-on-accent);
    border-color: var(--accent-color);
    text-decoration: none;
}

.btn-abstract i {
    transition: transform 0.3s ease;
}

.btn-abstract.expanded i {
    transform: rotate(180deg);
}

.btn-doi,
.btn-code {
    background-color: var(--link-color);
    color: #ffffff;
    border: 1px solid var(--link-color);
}

.btn-doi:hover,
.btn-code:hover {
    background-color: transparent;
    color: var(--link-color);
    text-decoration: none;
}

.paper-abstract {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease, opacity 0.3s ease;
    opacity: 0;
    background-color: color-mix(in srgb, var(--surface-elevated) 88%, transparent);
    border-radius: 8px;
    margin-top: 0;
    padding: 0 15px;
}

.paper-abstract.expanded {
    max-height: 520px;
    opacity: 1;
    padding: 15px;
    margin-top: 12px;
}

.paper-abstract p {
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.65;
    color: var(--text-color-light);
    text-align: justify;
}

#teaching p {
    text-align: left;
    max-width: none;
    margin-left: 0;
    margin-right: 0;
}

#teaching .section-title {
    text-align: left;
    font-size: clamp(2.1rem, 3vw, 2.6rem);
    margin-bottom: 16px;
}

.teaching-group-title {
    font-size: clamp(1.35rem, 1.65vw, 1.6rem);
    margin-top: 18px;
    margin-bottom: 8px;
}

.teaching-list {
    margin-left: 24px;
    margin-bottom: 22px;
}

.teaching-list li {
    color: var(--text-color-light);
    font-size: 1.05rem;
    line-height: 1.7;
}

footer {
    padding: 42px 20px;
    background-color: var(--footer-bg);
    border-top: 1px solid var(--border-color);
    margin-top: 52px;
    transition: background-color 0.3s, border-color 0.3s;
}

.footer-content {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 28px;
}

.footer-left,
.footer-right {
    min-width: 260px;
}

.footer-name {
    margin-bottom: 4px;
    font-family: 'Cormorant Garamond', Georgia, serif;
    font-size: 1.45rem;
    color: var(--text-color);
}

.footer-social {
    display: flex;
    gap: 14px;
}

.footer-social a {
    font-size: 1.7rem;
    color: var(--text-color-light);
    transition: color 0.3s, transform 0.2s;
}

.footer-social a:hover {
    color: var(--accent-color);
    transform: translateY(-2px);
    text-decoration: none;
}

.footer-right {
    text-align: left;
}

.footer-right p {
    margin-bottom: 4px;
    font-size: 0.94rem;
    line-height: 1.45;
    color: var(--text-color-light);
}

#back-to-top {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--back-to-top-bg);
    color: var(--back-to-top-text);
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-soft);
    transition: background-color 0.3s, opacity 0.3s, transform 0.3s;
    z-index: 1000;
    opacity: 0;
    transform: translateY(20px);
}

#back-to-top.show {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

#back-to-top:hover {
    filter: brightness(1.08);
    transform: translateY(-2px);
}

@keyframes gentle-reveal {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 900px) {
    header {
        padding: 14px 20px;
    }

    .top-nav {
        gap: 16px;
    }

    .top-nav a {
        font-size: 0.9rem;
    }

    .profile-container {
        flex-direction: column;
        align-items: center;
    }

    .profile-column-left {
        width: 80%;
        max-width: 320px;
        margin-bottom: 4px;
    }

    .profile-column-right {
        width: 100%;
    }

    .footer-content {
        gap: 20px;
    }

    .footer-right p {
        font-size: 0.88rem;
    }
}

@media (max-width: 640px) {
    header {
        flex-wrap: wrap;
        align-items: center;
        row-gap: 8px;
        padding: 12px 18px;
    }

    .logo a {
        font-size: 1.7rem;
    }

    .menu-toggle {
        display: inline-flex;
        margin-left: auto;
    }

    .top-nav {
        order: 3;
        position: static;
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
        margin: 0;
        padding-top: 10px;
        border-top: 1px solid var(--border-color);
        background: transparent;
    }

    body.nav-open .top-nav {
        display: flex;
    }

    .top-nav a {
        font-size: 0.88rem;
        letter-spacing: 0.08em;
        padding: 4px 0;
        width: fit-content;
        display: inline-block;
    }

    .search-box {
        display: none;
    }

    .header-controls {
        margin-left: 10px;
    }

    main {
        padding: 0 18px;
    }

    .section {
        padding: 44px 0 34px;
    }

    .profile-column-right {
        padding: 4px 0;
    }

    .paper-content {
        padding: 14px;
    }

    .teaching-group-title {
        margin-top: 18px;
    }

    .footer-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 18px;
    }

    .footer-left,
    .footer-right {
        min-width: auto;
        width: 100%;
    }
}

@media (max-width: 380px) {
    .header-controls {
        gap: 8px;
    }
}