/* ---------- Global reset ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* ---------- Global layout / colors ---------- */
body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: radial-gradient(circle at top left, #1f2937 0, #020617 45%, #020617 100%);
    color: #e5e7eb;
    line-height: 1.6;
}

a {
    color: inherit;
    text-decoration: none;
}

.container {
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ---------- Header & navigation ---------- */
.site-header {
    background: transparent;
    padding: 1.2rem 0 0.5rem;
}

.top-bar {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

@media (min-width: 768px) {
    .top-bar {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
}

.name {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    color: #f9fafb;
}

.nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.nav a {
    padding: 0.3rem 0.9rem;
    border-radius: 999px;
    font-size: 0.9rem;
    color: #d1d5db;
    border: 1px solid transparent;
    transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease,
        transform 0.1s ease;
}

.nav a:hover {
    background: rgba(148, 163, 184, 0.15);
    border-color: rgba(148, 163, 184, 0.4);
    transform: translateY(-1px);
}

.nav a.active {
    background: #4f46e5;
    color: #f9fafb;
    border-color: #4f46e5;
}

/* ---------- Hero section ---------- */
.hero {
    padding: 3rem 0 3.5rem;
}

.hero-content {
    display: grid;
    gap: 2.5rem;
    align-items: center;
    background: radial-gradient(circle at top left, #111827 0, #020617 55%, #020617 100%);
    border-radius: 1.75rem;
    border: 1px solid rgba(148, 163, 184, 0.3);
    box-shadow: 0 24px 60px rgba(15, 23, 42, 0.75);
    padding: 2.5rem;
}

@media (min-width: 900px) {
    .hero-content {
        grid-template-columns: minmax(0, 3fr) minmax(0, 2.2fr);
    }
}

.hero-text {
    max-width: 640px;
}

.hero-kicker {
    font-size: 0.75rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: #9ca3af;
    margin-bottom: 0.8rem;
}

.hero-title {
    font-size: 2.2rem;
    line-height: 1.2;
    margin-bottom: 0.4rem;
    color: #f9fafb;
}

.hero-highlight {
    color: #f9738f;
    position: relative;
    display: inline-block;
    animation: glow 2.8s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        text-shadow: 0 0 6px rgba(248, 113, 113, 0.6),
                     0 0 18px rgba(244, 63, 94, 0.5);
    }
    to {
        text-shadow: 0 0 2px rgba(248, 113, 113, 0.2),
                     0 0 10px rgba(244, 63, 94, 0.3);
    }
}

.hero-subtitle {
    font-size: 1rem;
    font-weight: 500;
    color: #e5e7eb;
    margin-bottom: 1rem;
}

.hero-intro {
    font-size: 0.96rem;
    color: #d1d5db;
    margin-bottom: 1.6rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.9rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.6rem 1.4rem;
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease,
        box-shadow 0.2s ease, transform 0.1s ease;
}

.btn-primary {
    background: linear-gradient(135deg, #6366f1, #ec4899);
    color: #f9fafb;
    box-shadow: 0 14px 30px rgba(99, 102, 241, 0.5);
}

.btn-primary:hover {
    box-shadow: 0 18px 40px rgba(99, 102, 241, 0.6);
    transform: translateY(-1px);
}

.btn-secondary {
    background: transparent;
    color: #e5e7eb;
    border-color: rgba(148, 163, 184, 0.7);
}

.btn-secondary:hover {
    background: rgba(148, 163, 184, 0.15);
    border-color: rgba(148, 163, 184, 0.9);
}

/* ---------- Hero photo card ---------- */
.hero-photo {
    display: flex;
    justify-content: center;
}

.hero-photo-frame {
    width: 260px;
    height: 260px;
    border-radius: 1.8rem;
    padding: 0.2rem;
    background: conic-gradient(from 140deg, #6366f1, #ec4899, #22c55e, #6366f1);
    box-shadow: 0 18px 45px rgba(15, 23, 42, 0.8);
    animation: float 6s ease-in-out infinite;
}

.hero-photo-frame img {
    width: 100%;
    height: 100%;
    border-radius: 1.5rem;
    display: block;
    object-fit: cover;
}

/* subtle floating animation */
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}

/* ---------- Sections (other pages + About block) ---------- */
.section {
    padding: 3rem 0;
    background: transparent;
}

.section-alt {
    background: rgba(15, 23, 42, 0.9);
    border-top: 1px solid rgba(148, 163, 184, 0.25);
    border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.section h2 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: #f9fafb;
}

.section p {
    font-size: 0.95rem;
    color: #d1d5db;
    max-width: 70rem;
}

/* For lists in research/publications pages */
.section ul {
    list-style: disc;
    padding-left: 1.4rem;
    margin-top: 0.6rem;
}

.section li {
    margin-bottom: 0.4rem;
}

/* ---------- Cards (experience page) ---------- */
.cards {
    display: grid;
    gap: 1.2rem;
}

@media (min-width: 768px) {
    .cards {
        grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    }
}

.card {
    background: rgba(15, 23, 42, 0.9);
    border-radius: 1.1rem;
    padding: 1.2rem 1.3rem;
    border: 1px solid rgba(148, 163, 184, 0.4);
    box-shadow: 0 12px 30px rgba(15, 23, 42, 0.6);
}

.card h3 {
    font-size: 1.05rem;
    margin-bottom: 0.4rem;
    color: #f9fafb;
}

.card p {
    font-size: 0.9rem;
    color: #d1d5db;
}

/* ---------- Footer ---------- */
.site-footer {
    background: #020617;
    border-top: 1px solid rgba(148, 163, 184, 0.25);
    padding: 1.4rem 0 1.2rem;
    text-align: center;
    color: #9ca3af;
    font-size: 0.8rem;
}

/* ---------- Small-screen tweaks ---------- */
@media (max-width: 599px) {
    .hero-content {
        padding: 1.8rem;
    }

    .hero-title {
        font-size: 1.85rem;
    }

    .hero-photo-frame {
        width: 220px;
        height: 220px;
    }
}