/* css/styles.css */

:root {
    /* Color Palette - Bright Academic (Pure White) */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --text-primary: #0f172a;
    --text-secondary: #1e293b;
    --text-muted: #475569;

    /* Accents - Professional Blue & Teal (No Purple/Pink) */
    --accent-blue: #0ea5e9;
    /* Bright Blue */
    --accent-teal: #0d9488;
    /* Deep Teal */
    --accent-cyan: #06b6d4;
    --accent-pink: #0ea5e9;
    /* Cyan */

    /* Gradients */
    --gradient-neon: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
    --gradient-text: linear-gradient(90deg, var(--accent-blue), var(--accent-teal), var(--accent-cyan));

    /* Glassmorphism - Light Mode */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(15, 23, 42, 0.08);
    --glass-shadow: 0 10px 40px -10px rgba(0, 0, 0, 0.08);

    /* Typography */
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* Spacing & Layout */
    --nav-height: 80px;
    --max-width: 1100px;
    --radius-lg: 16px;
    --radius-md: 8px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html[data-theme="dark"] {
    --bg-primary: #0b1220;
    --bg-secondary: #111a2c;
    --text-primary: #e5edf8;
    --text-secondary: #c4d2e8;
    --text-muted: #94a6c3;
    --glass-bg: rgba(15, 23, 42, 0.75);
    --glass-border: rgba(148, 163, 184, 0.22);
    --glass-shadow: 0 12px 44px -12px rgba(0, 0, 0, 0.45);
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-primary);
    /* Pure white */
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.25s ease, color 0.25s ease;
    position: relative;
}

/* Global ambient animation (applies site-wide) */
body::before,
body::after {
    content: "";
    position: fixed;
    width: 42vmax;
    height: 42vmax;
    border-radius: 50%;
    filter: blur(72px);
    pointer-events: none;
    z-index: 0;
    opacity: 0.34;
    animation: ambientDrift 24s ease-in-out infinite;
}

body::before {
    background: rgba(14, 165, 233, 0.22);
    top: -16vmax;
    left: -14vmax;
}

body::after {
    background: rgba(13, 148, 136, 0.2);
    bottom: -16vmax;
    right: -14vmax;
    animation-delay: -9s;
}

body > * {
    position: relative;
    z-index: 1;
}

html[data-theme="dark"] body::before {
    background: rgba(56, 189, 248, 0.2);
    opacity: 0.4;
}

html[data-theme="dark"] body::after {
    background: rgba(45, 212, 191, 0.16);
    opacity: 0.36;
}

@keyframes ambientDrift {
    0% {
        transform: translate3d(0, 0, 0) scale(1);
    }

    50% {
        transform: translate3d(5vmax, -2vmax, 0) scale(1.08);
    }

    100% {
        transform: translate3d(-3vmax, 3vmax, 0) scale(0.96);
    }
}

/* Typography Headings */
h1,
h2,
h3,
h4 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

h1 {
    font-size: 3rem;
    letter-spacing: -0.05em;
}

h2 {
    font-size: 2rem;
    letter-spacing: -0.02em;
}

h3 {
    font-size: 1.5rem;
}

a {
    color: var(--accent-blue);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    text-decoration: underline;
    color: var(--accent-teal);
}

/* ----- Text Animations ----- */

/* 1. Gradient Text Utility */
.text-gradient {
    background: var(--gradient-text);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% auto;
    animation: shine 5s linear infinite;
    display: inline-block;
}

@keyframes shine {
    to {
        background-position: 200% center;
    }
}

/* 2. Highlight Animate (Triggers on Scroll Reveal) */
.highlight-animate {
    position: relative;
    display: inline-block;
    z-index: 1;
    font-weight: 600;
    color: var(--text-primary);
}

.highlight-animate::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 2px;
    width: 100%;
    height: 35%;
    background: rgba(56, 189, 248, 0.4);
    z-index: -1;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 1s cubic-bezier(0.5, 0, 0, 1);
    transition-delay: 0.3s;
}

.reveal.active .highlight-animate::after {
    transform: scaleX(1);
}

/* 3. Typewriter Cursor */
.typewriter-cursor {
    animation: blink-caret 0.75s step-end infinite;
    color: var(--accent-teal);
    font-weight: 300;
    margin-left: 2px;
}

@keyframes blink-caret {

    from,
    to {
        opacity: 0;
    }

    50% {
        opacity: 1;
    }
}

/* ----- Navigation ----- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: var(--transition);
    background: transparent;
}

.navbar.scrolled {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.nav-container {
    width: 100%;
    max-width: var(--max-width);
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-primary);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.particle-section > *:not(.hero-particles) {
    position: relative;
    z-index: 1;
}

.particle-section {
    isolation: isolate;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.95rem;
    position: relative;
    text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background: var(--gradient-neon);
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

/* Mobile Menu Toggle */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
}

.theme-toggle {
    background: transparent;
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    border-radius: 999px;
    padding: 0.42rem 0.78rem;
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    cursor: pointer;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: rgba(14, 165, 233, 0.12);
    border-color: rgba(14, 165, 233, 0.45);
}

/* ----- Main Layout ----- */
main {
    min-height: calc(100vh - var(--nav-height));
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: calc(var(--nav-height) + 3rem) 2rem 4rem;
    opacity: 0;
    transform: translateY(12px);
    transition: opacity 0.55s ease, transform 0.55s ease;
}

body.page-ready main {
    opacity: 1;
    transform: translateY(0);
}

/* Staggered page-enter for all top-level blocks (visible on all tabs/pages) */
main > * {
    opacity: 0;
    transform: translateY(18px);
}

body.page-ready main > * {
    animation: sectionEnter 0.65s cubic-bezier(0.2, 0.8, 0.2, 1) forwards;
}

body.page-ready main > *:nth-child(1) { animation-delay: 0.08s; }
body.page-ready main > *:nth-child(2) { animation-delay: 0.16s; }
body.page-ready main > *:nth-child(3) { animation-delay: 0.24s; }
body.page-ready main > *:nth-child(4) { animation-delay: 0.32s; }
body.page-ready main > *:nth-child(5) { animation-delay: 0.40s; }
body.page-ready main > *:nth-child(6) { animation-delay: 0.48s; }

@keyframes sectionEnter {
    from {
        opacity: 0;
        transform: translateY(18px);
    }

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

/* ----- Scroll Reveal Animations ----- */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.5, 0, 0, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

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

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

.section {
    margin-bottom: 6rem;
}

/* Glass Card Component */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--glass-shadow);
    position: relative;
    overflow: hidden;
    transition: var(--transition);
}

.glass-card:hover {
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
    border-color: rgba(15, 23, 42, 0.12);
}

/* --- Research Page Overrides for White Theme --- */

.search-input {
    background: #ffffff !important;
    border: 1px solid #cbd5e1 !important;
    color: #0f172a !important;
}

.search-input::placeholder {
    color: #64748b !important;
}

.research-item {
    background: #ffffff !important;
    border: 1px solid #e2e8f0 !important;
}

.res-title {
    color: #0f172a !important;
}

.res-tag {
    background: #f1f5f9 !important;
    color: #475569 !important;
    border: 1px solid #cbd5e1 !important;
}

.filter-btn {
    background: #ffffff !important;
    border: 1px solid #cbd5e1 !important;
    color: #475569 !important;
}

.filter-btn:hover {
    background: #f8fafc !important;
    color: #0f172a !important;
}

.filter-btn.active {
    background: var(--accent-blue) !important;
    color: white !important;
    border-color: var(--accent-blue) !important;
}

/* ----- Featured Projects / Publications ----- */
.projects-grid {
    display: flex;
    overflow-x: auto;
    overflow-y: hidden;
    gap: 2.5rem;
    margin-top: 3rem;
    padding-bottom: 2rem;
    /* Give shadow space to breathe */
    padding-inline: 1rem;
    /* Pad edges so cards don't stick to the screen boundary */
    scroll-snap-type: x mandatory;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    /* Momentum scrolling on iOS */
    cursor: grab;
}

.projects-grid.active {
    cursor: grabbing;
    cursor: -webkit-grabbing;
    /* Disable snap while dragging for smoother movement */
    scroll-snap-type: none;
}

/* Minimalist Scroll Buttons for Carousel */
.carousel-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: transparent;
    /* No background */
    border: none;
    /* No border */
    color: var(--accent-teal);
    /* Teal chevron */
    font-size: 2.2rem;
    /* Large icon */
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 20;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    opacity: 0.6;
    /* Slightly faded when inactive */
    padding: 10px;
}

.carousel-btn:hover {
    color: var(--accent-blue);
    transform: translateY(-50%) scale(1.2);
    /* Enhance the bounce */
    opacity: 1;
}

.carousel-btn:active {
    transform: translateY(-50%) scale(0.95);
}

/* Push them slightly outside the grid content */
.carousel-btn.left {
    left: 5px;
}

.carousel-btn.right {
    right: 5px;
}

/* Hide the buttons on small screens since swiping is more natural */
@media (max-width: 768px) {
    .carousel-btn {
        display: none;
    }
}

/* Hide scrollbar for a cleaner look */
.projects-grid::-webkit-scrollbar {
    display: none;
}

.projects-grid {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

.paper-card {
    display: flex;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    height: 100%;
    position: relative;
    box-shadow: 0 8px 32px 0 rgba(14, 165, 233, 0.05);
    /* Sizing constraints for horizontal flex layout */
    min-width: 350px;
    max-width: 450px;
    flex: 0 0 auto;
    scroll-snap-align: start;
}



.paper-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border-radius: 16px;
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.08), rgba(14, 165, 233, 0.08));
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: 0;
    pointer-events: none;
}

.paper-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 45px 0 rgba(14, 165, 233, 0.15);
    border-color: rgba(14, 165, 233, 0.3);
}

.paper-card:hover::before {
    opacity: 1;
}

.paper-card-image {
    width: 100%;
    aspect-ratio: 16/9;
    overflow: hidden;
    position: relative;
    z-index: 1;
    background: rgba(2, 6, 23, 0.06);
}

.paper-card-image img {
    width: 100%;
    height: 100%;
    display: block;
    object-fit: contain;
    object-position: center;
    padding: 0.35rem;
    transition: transform 0.35s ease;
}

.paper-card:hover .paper-card-image img {
    transform: scale(1.02);
}

.badge {
    position: absolute;
    top: 15px;
    left: 15px;
    background: linear-gradient(135deg, var(--accent-teal), var(--accent-blue));
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    z-index: 10;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.paper-card-text {
    padding: 1.8rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    z-index: 1;
    position: relative;
}

.paper-card-top {
    display: flex;
    flex-direction: column;
}

.paper-card-title {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: -0.3px;
    line-height: 1.4;
    margin-bottom: 0.8rem;
    display: block;
    background: linear-gradient(90deg, var(--accent-blue), var(--accent-teal));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    background-size: 200% auto;
    text-decoration: none;
}

.paper-card-title:hover {
    background-position: right center;
    opacity: 0.9;
}

.paper-card-authors {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 0.45rem;
}

.paper-card-actions {
    display: flex;
    gap: 0.6rem;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 0.75rem;
}

.paper-card-authors strong {
    color: var(--text-primary);
    font-weight: 700;
}

.paper-card-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 8px 16px;
    background: rgba(14, 165, 233, 0.1);
    border: 1px solid rgba(14, 165, 233, 0.3);
    border-radius: 20px;
    color: var(--accent-blue);
    font-size: 0.9rem;
    font-weight: 600;
    width: max-content;
    margin-bottom: 0;
    transition: all 0.3s ease;
}

.paper-card-btn:hover {
    background: rgba(14, 165, 233, 0.2);
    transform: translateY(-2px);
    color: var(--accent-blue);
    text-decoration: none;
    box-shadow: 0 4px 10px rgba(14, 165, 233, 0.15);
}

.paper-card-desc {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
    margin-top: 0.25rem;
}

/* ----- Education Timeline ----- */
.education-timeline {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem 0;
}

/* The vertical line */
.education-timeline::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 60px;
    /* Aligned with center of logos */
    width: 2px;
    background: linear-gradient(to bottom, var(--accent-blue) 0%, var(--accent-teal) 100%);
    opacity: 0.3;
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    display: flex;
    align-items: flex-start;
    gap: 2.5rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-logo {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    position: relative;
    z-index: 2;
    box-shadow: 0 8px 32px rgba(14, 165, 233, 0.1);
    overflow: hidden;
}

.timeline-logo img {
    max-width: 70%;
    max-height: 70%;
    object-fit: contain;
}

.education-card {
    flex-grow: 1;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    overflow: hidden;
    position: relative;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.03);
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(14, 165, 233, 0.08);
}

.education-card-header {
    background: linear-gradient(to right, rgba(14, 165, 233, 0.1), rgba(6, 182, 212, 0.05));
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--glass-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.school-name {
    font-size: 1.4rem;
    color: var(--text-primary);
    margin-bottom: 0.3rem;
}

.degree-name {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.date-badge {
    background: rgba(14, 165, 233, 0.15);
    color: var(--accent-blue);
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.education-card-body {
    padding: 1.5rem 2rem 3.5rem 2rem;
    position: relative;
}

.education-card-body ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.education-card-body li {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    display: flex;
    align-items: flex-start;
    gap: 0.8rem;
    line-height: 1.5;
}

.education-card-body li:last-child {
    margin-bottom: 0;
}

.text-teal {
    color: var(--accent-teal);
    margin-top: 4px;
}

.visit-btn {
    position: absolute;
    bottom: 1rem;
    right: 1.5rem;
    background: rgba(14, 165, 233, 0.1);
    color: var(--accent-blue);
    padding: 0.5rem 1.2rem;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s ease;
}

.visit-btn:hover {
    background: var(--accent-blue);
    color: white;
}

@media (max-width: 768px) {
    .education-timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: column;
        gap: 1rem;
    }

    .timeline-logo {
        width: 60px;
        height: 60px;
        margin-left: -10px;
        /* Align with line */
    }

    .timeline-logo img {
        max-width: 60%;
        max-height: 60%;
    }

    .education-card-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .visit-btn {
        position: static;
        display: inline-block;
        margin-top: 1.5rem;
    }
}

/* ----- Footer ----- */
footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    border-top: 1px solid var(--glass-border);
    margin-top: 2rem;
}

footer a {
    color: var(--text-secondary);
    font-weight: 500;
}

/* ----- Responsive ----- */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-height);
        left: 0;
        width: 100%;
        background: var(--bg-primary);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid var(--glass-border);
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
    }

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

    .mobile-menu-btn {
        display: block;
    }
}