/* ── Variables ─────────────────────────────────────────── */
:root {
    --navy:   #07182e;
    --deep:   #0d2744;
    --teal:   #00c2a8;
    --teal2:  #00a88f;
    --gold:   #e8c96d;
    --white:  #f0f4f8;
    --muted:  #8ba3bc;
    --glass:  rgba(255,255,255,0.05);
    --card:   rgba(255,255,255,0.04);
    --shadow: 0 8px 32px rgba(0,0,0,0.35);
}

*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }

body {
    background: var(--navy);
    color: var(--white);
    font-family: 'DM Sans', sans-serif;
    font-weight: 300;
    line-height: 1.7;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: 9999;
    opacity: 0.4;
}

h1, h2, h3 { font-family: 'DM Serif Display', serif; font-weight: 400; line-height: 1.15; }

.label {
    font-size: 0.7rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--teal);
    font-weight: 600;
    margin-bottom: 12px;
    display: block;
}

/* ── Navbar ────────────────────────────────────────────── */
header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    padding: 0 5%;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    backdrop-filter: blur(18px);
    background: rgba(7,24,46,0.72);
    border-bottom: 1px solid rgba(0,194,168,0.12);
}

.logo {
    font-family: 'DM Serif Display', serif;
    font-size: 1.15rem;
    color: var(--white);
}
.logo span { color: var(--teal); }

nav ul { list-style: none; display: flex; gap: 28px; }
nav a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.8rem;
    letter-spacing: 0.04em;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}
nav a::after {
    content: '';
    position: absolute;
    bottom: -3px; left: 0; right: 0;
    height: 1px;
    background: var(--teal);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.25s;
}
nav a:hover { color: var(--white); }
nav a:hover::after, nav a.active::after { transform: scaleX(1); }
nav a.active { color: var(--teal); }

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 4px;
}
.hamburger span {
    display: block;
    width: 24px; height: 2px;
    background: var(--white);
    border-radius: 2px;
    transition: 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-menu {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 64px; left: 0; right: 0;
    background: rgba(7,24,46,0.97);
    backdrop-filter: blur(20px);
    padding: 24px 6%;
    gap: 20px;
    border-bottom: 1px solid rgba(0,194,168,0.12);
    z-index: 999;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
    color: var(--white);
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    border-bottom: 1px solid rgba(255,255,255,0.07);
    padding-bottom: 14px;
}

/* ── Hero ──────────────────────────────────────────────── */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 100px 6% 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(0,194,168,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,194,168,0.04) 1px, transparent 1px);
    background-size: 60px 60px;
    animation: gridMove 20s linear infinite;
}
@keyframes gridMove {
    0% { background-position: 0 0; }
    100% { background-position: 60px 60px; }
}

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    pointer-events: none;
}
.orb-1 {
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(0,194,168,0.15), transparent 70%);
    top: -150px; right: 0%;
    animation: float 8s ease-in-out infinite;
}
.orb-2 {
    width: 400px; height: 400px;
    background: radial-gradient(circle, rgba(232,201,109,0.10), transparent 70%);
    bottom: 0%; left: 2%;
    animation: float 11s ease-in-out infinite reverse;
}
.orb-3 {
    width: 300px; height: 300px;
    background: radial-gradient(circle, rgba(0,100,200,0.10), transparent 70%);
    top: 40%; left: 45%;
    animation: float 14s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0) scale(1); }
    50%       { transform: translateY(-30px) scale(1.05); }
}

.particles { position: absolute; inset: 0; pointer-events: none; z-index: 1; }
.particle {
    position: absolute;
    border-radius: 50%;
    background: var(--teal);
    opacity: 0;
    animation: particleFloat var(--dur, 6s) ease-in-out infinite;
    animation-delay: var(--delay, 0s);
}
@keyframes particleFloat {
    0%   { opacity: 0; transform: translateY(0) scale(0); }
    20%  { opacity: 0.5; transform: translateY(-20px) scale(1); }
    80%  { opacity: 0.2; }
    100% { opacity: 0; transform: translateY(-80px) scale(0.5); }
}

.hero-inner {
    position: relative;
    z-index: 2;
    width: 100%;
    max-width: 1200px;
    display: grid;
    grid-template-columns: 1fr 460px;
    gap: 60px;
    align-items: center;
}

.hero-content { max-width: 620px; }

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: rgba(0,194,168,0.10);
    border: 1px solid rgba(0,194,168,0.28);
    border-radius: 100px;
    padding: 7px 18px;
    font-size: 0.75rem;
    color: var(--teal);
    letter-spacing: 0.06em;
    margin-bottom: 28px;
    animation: fadeUp 0.8s ease both;
}
.badge-dot {
    width: 7px; height: 7px;
    background: var(--teal);
    border-radius: 50%;
    box-shadow: 0 0 6px var(--teal);
    animation: pulse 2s ease infinite;
    flex-shrink: 0;
}
@keyframes pulse {
    0%, 100% { opacity: 1; box-shadow: 0 0 6px var(--teal); }
    50%       { opacity: 0.5; box-shadow: 0 0 16px var(--teal); }
}

.hero-content h1 {
    font-size: clamp(3.2rem, 6vw, 5.5rem);
    line-height: 1.0;
    animation: fadeUp 0.8s 0.1s ease both;
    display: flex;
    flex-direction: column;
    gap: 2px;
}
.line-1 { display: block; color: var(--white); }
.line-2 { display: block; }
.hero-content h1 em { font-style: italic; color: var(--teal); }

.hero-role {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 22px 0 18px;
    animation: fadeUp 0.8s 0.2s ease both;
}
.role-chip {
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.12);
    color: var(--muted);
    font-size: 0.75rem;
    padding: 4px 12px;
    border-radius: 100px;
    letter-spacing: 0.04em;
}

.hero-sub {
    font-size: clamp(0.95rem, 2vw, 1.12rem);
    color: var(--gold);
    font-family: 'DM Serif Display', serif;
    font-style: italic;
    margin-bottom: 36px;
    animation: fadeUp 0.8s 0.3s ease both;
    opacity: 0.9;
}

.hero-btns {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    animation: fadeUp 0.8s 0.4s ease both;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 26px;
    border-radius: 8px;
    font-size: 0.84rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    text-decoration: none;
    transition: all 0.25s;
    cursor: pointer;
    border: none;
    font-family: 'DM Sans', sans-serif;
}
.btn-arrow { transition: transform 0.2s; }
.btn-primary:hover .btn-arrow { transform: translateX(4px); }

.btn-primary {
    background: linear-gradient(135deg, var(--teal), var(--teal2));
    color: var(--navy);
    font-weight: 600;
    box-shadow: 0 4px 20px rgba(0,194,168,0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(0,194,168,0.4); }

.btn-outline {
    background: transparent;
    color: var(--white);
    border: 1px solid rgba(255,255,255,0.18);
}
.btn-outline:hover { border-color: var(--teal); color: var(--teal); transform: translateY(-2px); }

.btn-ghost {
    background: transparent;
    color: var(--muted);
    border: 1px solid rgba(255,255,255,0.08);
    font-size: 0.8rem;
}
.btn-ghost:hover { color: var(--gold); border-color: rgba(232,201,109,0.3); transform: translateY(-2px); }

.hero-stats {
    display: flex;
    align-items: center;
    margin-top: 48px;
    padding-top: 36px;
    border-top: 1px solid rgba(255,255,255,0.08);
    animation: fadeUp 0.8s 0.5s ease both;
}
.stat-item { display: flex; flex-direction: column; padding: 0 32px 0 0; }
.stat-item:first-child { padding-left: 0; }
.stat-num {
    font-family: 'DM Serif Display', serif;
    font-size: 2.4rem;
    color: var(--teal);
    line-height: 1;
    display: inline-block;
}
.stat-suffix {
    font-family: 'DM Serif Display', serif;
    font-size: 1.4rem;
    color: var(--teal);
    display: inline;
    margin-left: 2px;
}
.stat-desc { font-size: 0.75rem; color: var(--muted); margin-top: 5px; letter-spacing: 0.03em; }
.stat-divider {
    width: 1px; height: 44px;
    background: rgba(255,255,255,0.1);
    margin: 0 32px 0 0;
    flex-shrink: 0;
}

/* ── Hero Visual ────────────────────────────────────────── */
.hero-visual {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeUp 0.9s 0.3s ease both;
}

.profile-ring {
    position: absolute;
    width: 420px; height: 420px;
    border-radius: 50%;
    border: 1px solid rgba(0,194,168,0.15);
    animation: spin 20s linear infinite;
}
.profile-ring::before {
    content: '';
    position: absolute;
    top: -4px; left: 50%;
    transform: translateX(-50%);
    width: 8px; height: 8px;
    background: var(--teal);
    border-radius: 50%;
    box-shadow: 0 0 12px var(--teal);
}
@keyframes spin {
    from { transform: rotate(0deg); }
    to   { transform: rotate(360deg); }
}

.profile-grid {
    position: absolute;
    width: 340px; height: 400px;
    background-image:
        linear-gradient(rgba(0,194,168,0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0,194,168,0.06) 1px, transparent 1px);
    background-size: 24px 24px;
    border-radius: 20px;
    z-index: 0;
}

.profile-card {
    position: relative;
    z-index: 2;
    width: 300px;
    border-radius: 24px;
    overflow: visible;
    background: linear-gradient(160deg, rgba(0,194,168,0.08), rgba(13,39,68,0.6));
    border: 1px solid rgba(0,194,168,0.2);
    box-shadow: 0 30px 80px rgba(0,0,0,0.5), inset 0 1px 0 rgba(255,255,255,0.08);
    backdrop-filter: blur(10px);
    transition: transform 0.3s ease;
}

.profile-img-wrapper {
    width: 100%; height: 360px;
    position: relative;
    border-radius: 24px 24px 0 0;
    overflow: hidden;
}
.profile-img {
    width: 100%; height: 100%;
    object-fit: cover;
    object-position: top center;
    display: block;
    transition: transform 0.4s ease;
}
.profile-card:hover .profile-img { transform: scale(1.04); }

.profile-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%; height: 100%;
    background: linear-gradient(160deg, rgba(0,194,168,0.12), rgba(13,39,68,0.8));
    gap: 12px;
    border-radius: 24px 24px 0 0;
}
.placeholder-icon { font-size: 3.5rem; }
.placeholder-text {
    font-size: 0.85rem;
    color: var(--white);
    text-align: center;
    font-weight: 500;
}
.placeholder-text small {
    font-size: 0.7rem;
    color: var(--teal);
    font-family: monospace;
    background: rgba(0,194,168,0.1);
    padding: 2px 8px;
    border-radius: 4px;
    display: block;
    margin-top: 6px;
}

.profile-img-wrapper::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 80px;
    background: linear-gradient(transparent, rgba(13,39,68,0.7));
    pointer-events: none;
}

.profile-chip {
    position: absolute;
    background: rgba(7,24,46,0.92);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(0,194,168,0.2);
    border-radius: 100px;
    padding: 7px 14px;
    font-size: 0.72rem;
    color: var(--white);
    font-weight: 500;
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 6px;
    z-index: 10;
    box-shadow: 0 4px 20px rgba(0,0,0,0.4);
}
.chip-dot { width: 6px; height: 6px; background: var(--teal); border-radius: 50%; }
.chip-live {
    width: 6px; height: 6px;
    background: #4ade80;
    border-radius: 50%;
    box-shadow: 0 0 6px #4ade80;
    animation: pulse 2s ease infinite;
}
.chip-1 { top: 20px; left: -30px; animation: chipFloat 5s ease-in-out infinite; }
.chip-2 { bottom: 70px; left: -20px; animation: chipFloat 7s ease-in-out infinite reverse; }
.chip-3 { top: 50px; right: -20px; animation: chipFloat 6s ease-in-out infinite 1s; }
@keyframes chipFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.float-badge {
    position: absolute;
    background: rgba(0,194,168,0.12);
    border: 1px solid rgba(0,194,168,0.3);
    color: var(--teal);
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    padding: 5px 12px;
    border-radius: 6px;
    z-index: 3;
}
.badge-gis    { bottom: -10px; right: -20px; animation: chipFloat 8s ease-in-out infinite; }
.badge-matlab { bottom: 40px;  left: -45px;  animation: chipFloat 9s ease-in-out infinite reverse; }
.badge-python { top: -15px;   right: 20px;  animation: chipFloat 7s ease-in-out infinite 0.5s; }

.scroll-hint {
    position: absolute;
    bottom: 28px; left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--muted);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    z-index: 2;
    animation: fadeIn 1s 1s ease both;
}
.scroll-mouse {
    width: 22px; height: 34px;
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: 12px;
    display: flex;
    justify-content: center;
    padding-top: 6px;
}
.scroll-wheel {
    width: 3px; height: 7px;
    background: var(--teal);
    border-radius: 2px;
    animation: scrollWheel 2s ease infinite;
}
@keyframes scrollWheel {
    0%   { transform: translateY(0); opacity: 1; }
    100% { transform: translateY(10px); opacity: 0; }
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(24px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ── Section Common ─────────────────────────────────────── */
section { padding: 96px 6%; }

.section-header { margin-bottom: 56px; }
.section-header h2 { font-size: clamp(2rem, 4vw, 3rem); }
.section-header p { color: var(--muted); font-size: 1rem; margin-top: 10px; max-width: 580px; }

.fade-in {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.65s ease, transform 0.65s ease;
}
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ── About ──────────────────────────────────────────────── */
#about { background: var(--deep); }

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}
.about-avatar {
    position: relative;
    display: flex;
    justify-content: center;
}
.avatar-frame {
    width: 340px; height: 340px;
    border-radius: 20px;
    background: linear-gradient(135deg, rgba(0,194,168,0.1), rgba(232,201,109,0.06));
    border: 1px solid rgba(0,194,168,0.2);
    position: relative;
    overflow: hidden;
}
.about-img {
    width: 100%; height: 100%;
    object-fit: cover;
    object-position: top;
    display: block;
}
.about-placeholder {
    display: none;
    align-items: center;
    justify-content: center;
    width: 100%; height: 100%;
    font-size: 5rem;
    color: rgba(0,194,168,0.35);
}
.avatar-frame::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--teal), var(--gold));
}
.avatar-corner {
    position: absolute;
    width: 70px; height: 70px;
    border: 2px solid rgba(0,194,168,0.3);
    border-radius: 8px;
    z-index: 2;
    pointer-events: none;
}
.avatar-corner.tl { top: -10px; left: -10px; border-right: none; border-bottom: none; }
.avatar-corner.br { bottom: -10px; right: -10px; border-left: none; border-top: none; }

.exp-card {
    position: absolute;
    bottom: -16px; right: -16px;
    background: linear-gradient(135deg, var(--teal), var(--teal2));
    border-radius: 14px;
    padding: 16px 20px;
    text-align: center;
    box-shadow: 0 8px 28px rgba(0,194,168,0.4);
    z-index: 3;
}
.exp-num {
    font-family: 'DM Serif Display', serif;
    font-size: 2rem;
    color: var(--navy);
    line-height: 1;
}
.exp-label {
    font-size: 0.65rem;
    color: rgba(7,24,46,0.75);
    font-weight: 600;
    letter-spacing: 0.04em;
    line-height: 1.3;
    margin-top: 4px;
}

.about-text h2 { font-size: clamp(1.8rem, 3vw, 2.5rem); margin-bottom: 18px; }
.about-text p { color: var(--muted); margin-bottom: 14px; font-size: 0.95rem; }

/* Education items */
.about-edu { margin: 20px 0; display: flex; flex-direction: column; gap: 12px; }
.edu-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    background: rgba(0,194,168,0.06);
    border: 1px solid rgba(0,194,168,0.15);
    border-radius: 10px;
    padding: 12px 16px;
}
.edu-icon { font-size: 1.2rem; flex-shrink: 0; margin-top: 2px; }
.edu-degree { font-size: 0.87rem; font-weight: 500; color: var(--white); }
.edu-school { font-size: 0.75rem; color: var(--teal); margin-top: 3px; }

.about-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.tag {
    background: rgba(0,194,168,0.10);
    border: 1px solid rgba(0,194,168,0.25);
    color: var(--teal);
    font-size: 0.75rem;
    padding: 5px 14px;
    border-radius: 100px;
    letter-spacing: 0.05em;
}

/* ── Experience / Timeline ──────────────────────────────── */
#experience { background: var(--navy); }

.timeline { position: relative; display: flex; flex-direction: column; gap: 0; }
.timeline::before {
    content: '';
    position: absolute;
    left: 16px; top: 8px; bottom: 8px;
    width: 1px;
    background: linear-gradient(to bottom, var(--teal), rgba(0,194,168,0.1));
}

.timeline-item {
    position: relative;
    padding-left: 52px;
    padding-bottom: 48px;
}
.timeline-item:last-child { padding-bottom: 0; }

.timeline-dot {
    position: absolute;
    left: 9px; top: 8px;
    width: 15px; height: 15px;
    background: var(--teal);
    border-radius: 50%;
    border: 3px solid var(--navy);
    box-shadow: 0 0 0 2px var(--teal), 0 0 16px rgba(0,194,168,0.4);
    z-index: 2;
}

.timeline-content {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 16px;
    padding: 28px 28px 24px;
    transition: border-color 0.25s;
}
.timeline-content:hover { border-color: rgba(0,194,168,0.25); }

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
.timeline-header h3 { font-size: 1.15rem; color: var(--white); margin-bottom: 4px; }
.timeline-org { font-size: 0.82rem; color: var(--teal); font-weight: 500; }
.timeline-date {
    font-size: 0.75rem;
    color: var(--muted);
    background: rgba(255,255,255,0.06);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 100px;
    padding: 4px 14px;
    white-space: nowrap;
    flex-shrink: 0;
}
.timeline-desc { font-size: 0.88rem; color: var(--muted); line-height: 1.7; }

.timeline-roles { display: flex; flex-direction: column; gap: 16px; }
.role-item {
    background: rgba(0,194,168,0.04);
    border-left: 2px solid rgba(0,194,168,0.3);
    border-radius: 0 8px 8px 0;
    padding: 12px 16px;
}
.role-partner {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--gold);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 6px;
}
.role-item p { font-size: 0.85rem; color: var(--muted); line-height: 1.65; }

/* Collapsible extra roles */
.roles-extra {
    display: none;
    flex-direction: column;
    gap: 16px;
}
.roles-extra.open {
    display: flex;
    animation: fadeUp 0.4s ease both;
}

/* Show more / less toggle button */
.roles-toggle {
    margin-top: 4px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(0,194,168,0.08);
    border: 1px solid rgba(0,194,168,0.25);
    color: var(--teal);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    padding: 8px 18px;
    border-radius: 100px;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s, transform 0.2s;
    align-self: flex-start;
}
.roles-toggle:hover {
    background: rgba(0,194,168,0.15);
    border-color: rgba(0,194,168,0.5);
    transform: translateY(-1px);
}
.roles-toggle.active {
    background: rgba(0,194,168,0.12);
    border-color: var(--teal);
}

/* ── Skills ─────────────────────────────────────────────── */
#skills { background: var(--deep); }

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 20px;
}
.skill-card {
    background: var(--card);
    border: 1px solid rgba(255,255,255,0.07);
    border-radius: 12px;
    padding: 28px 24px;
    transition: border-color 0.25s, transform 0.25s, box-shadow 0.25s;
    position: relative;
    overflow: hidden;
}
.skill-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--teal), transparent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.35s;
}
.skill-card:hover { border-color: rgba(0,194,168,0.3); transform: translateY(-4px); box-shadow: 0 16px 40px rgba(0,0,0,0.3); }
.skill-card:hover::before { transform: scaleX(1); }
.skill-icon { font-size: 1.8rem; margin-bottom: 14px; display: block; }
.skill-card h3 { font-family: 'DM Sans', sans-serif; font-size: 0.92rem; font-weight: 600; color: var(--white); margin-bottom: 6px; }
.skill-card p { font-size: 0.78rem; color: var(--muted); }

/* ── Projects ────────────────────────────────────────────── */
#projects { background: var(--navy); }

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
}
.project-card {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 14px;
    padding: 32px 28px;
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}
.project-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0,194,168,0.06) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.3s;
}
.project-card:hover { border-color: rgba(0,194,168,0.3); transform: translateY(-6px); box-shadow: 0 24px 48px rgba(0,0,0,0.4); }
.project-card:hover::after { opacity: 1; }
.project-num {
    font-family: 'DM Serif Display', serif;
    font-size: 3rem;
    color: rgba(0,194,168,0.12);
    line-height: 1;
    margin-bottom: 8px;
}
.project-tags { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.ptag {
    font-size: 0.65rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    background: rgba(232,201,109,0.1);
    border: 1px solid rgba(232,201,109,0.25);
    color: var(--gold);
    padding: 3px 10px;
    border-radius: 4px;
}
.project-card h3 { font-size: 1.05rem; margin-bottom: 10px; color: var(--white); }
.project-card p { font-size: 0.84rem; color: var(--muted); line-height: 1.7; }

/* ── Gallery ─────────────────────────────────────────────── */
#gallery { background: var(--deep); }

/* Gallery Tabs */
.gallery-tabs {
    display: flex;
    gap: 12px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}
.gallery-tab {
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    color: var(--muted);
    padding: 12px 24px;
    border-radius: 100px;
    font-family: 'DM Sans', sans-serif;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.25s;
}
.gallery-tab:hover {
    border-color: rgba(0,194,168,0.4);
    color: var(--white);
}
.gallery-tab.active {
    background: var(--teal);
    border-color: var(--teal);
    color: var(--navy);
    font-weight: 600;
}

/* Gallery Categories */
.gallery-category {
    display: none;
}
.gallery-category.active {
    display: block;
    animation: fadeUp 0.4s ease both;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}
.gallery-item {
    position: relative;
    border-radius: 14px;
    overflow: hidden;
    aspect-ratio: 3/2;
    cursor: pointer;
    background: rgba(0,194,168,0.05);
}
.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    object-position: center;
    background: var(--deep);
    transition: transform 0.4s ease;
}
.gallery-item:hover img { transform: scale(1.08); }
.gallery-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(7,24,46,0.9) 0%, transparent 50%);
    display: flex;
    align-items: flex-end;
    padding: 20px;
    opacity: 0;
    transition: opacity 0.3s;
}
.gallery-item:hover .gallery-overlay { opacity: 1; }
.gallery-overlay span {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--white);
    letter-spacing: 0.03em;
}

/* ── Publications ───────────────────────────────────────── */
#publications { background: var(--deep); }

.pub-list { display: flex; flex-direction: column; gap: 20px; }
.pub-item {
    display: grid;
    grid-template-columns: 70px 1fr auto;
    align-items: start;
    gap: 24px;
    background: var(--card);
    border: 1px solid rgba(255,255,255,0.07);
    border-radius: 12px;
    padding: 24px 28px;
    transition: border-color 0.25s, transform 0.25s;
}
.pub-item:hover { border-color: rgba(0,194,168,0.3); transform: translateX(4px); }
.pub-year {
    font-family: 'DM Serif Display', serif;
    font-size: 1.7rem;
    color: rgba(0,194,168,0.35);
    padding-top: 2px;
}
.pub-body { display: flex; flex-direction: column; gap: 6px; }
.pub-title { font-size: 0.97rem; font-weight: 500; color: var(--white); line-height: 1.4; }
.pub-meta { font-size: 0.8rem; color: var(--muted); }
.pub-meta strong { color: var(--white); }
.pub-meta em { color: var(--teal); font-style: italic; }
.pub-doi {
    font-size: 0.75rem;
    color: var(--teal);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.2s;
    display: inline-block;
}
.pub-doi:hover { opacity: 1; text-decoration: underline; }
.pub-type {
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    background: rgba(0,194,168,0.1);
    color: var(--teal);
    padding: 4px 12px;
    border-radius: 100px;
    border: 1px solid rgba(0,194,168,0.2);
    white-space: nowrap;
    align-self: flex-start;
}

/* Academic grid */
.academic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 14px;
}
.academic-item {
    background: rgba(255,255,255,0.03);
    border: 1px solid rgba(255,255,255,0.07);
    border-radius: 10px;
    padding: 14px 18px;
    font-size: 0.84rem;
    color: var(--muted);
    line-height: 1.5;
    transition: border-color 0.2s, color 0.2s;
}
.academic-item:hover { border-color: rgba(0,194,168,0.25); color: var(--white); }

/* ── Contact ────────────────────────────────────────────── */
#contact { background: var(--navy); }

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: start;
}
.contact-info h2 { font-size: clamp(1.8rem, 3vw, 2.6rem); margin-bottom: 16px; }
.contact-info p { color: var(--muted); font-size: 0.95rem; margin-bottom: 32px; }

.contact-links { display: flex; flex-direction: column; gap: 14px; }
.contact-link {
    display: flex;
    align-items: center;
    gap: 14px;
    color: var(--muted);
    text-decoration: none;
    font-size: 0.88rem;
    transition: color 0.2s;
}
.contact-link:hover { color: var(--teal); }
.contact-link-icon {
    width: 38px; height: 38px;
    background: rgba(0,194,168,0.1);
    border: 1px solid rgba(0,194,168,0.2);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.95rem;
    flex-shrink: 0;
}

.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label {
    font-size: 0.75rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--muted);
    font-weight: 500;
}
.form-group input,
.form-group textarea {
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    padding: 12px 16px;
    color: var(--white);
    font-family: 'DM Sans', sans-serif;
    font-size: 0.92rem;
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
    resize: vertical;
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--muted); }
.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--teal);
    box-shadow: 0 0 0 3px rgba(0,194,168,0.12);
}
.form-group textarea { min-height: 120px; }

/* ── Toast ───────────────────────────────────────────────── */
.toast {
    position: fixed;
    bottom: 28px; right: 28px;
    background: var(--teal);
    color: var(--navy);
    padding: 14px 22px;
    border-radius: 8px;
    font-size: 0.88rem;
    font-weight: 600;
    transform: translateY(80px);
    opacity: 0;
    transition: all 0.4s;
    z-index: 9000;
    display: flex;
    align-items: center;
    gap: 8px;
}
.toast.show { transform: translateY(0); opacity: 1; }

/* ── Footer ─────────────────────────────────────────────── */
footer {
    background: #060f1e;
    padding: 32px 6%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
    border-top: 1px solid rgba(255,255,255,0.06);
}
footer p { font-size: 0.8rem; color: var(--muted); }
.footer-links { display: flex; gap: 24px; }
.footer-links a {
    color: var(--muted);
    text-decoration: none;
    font-size: 0.8rem;
    transition: color 0.2s;
}
.footer-links a:hover { color: var(--teal); }

/* ── Scroll to top ──────────────────────────────────────── */
#scrollTop {
    position: fixed;
    bottom: 28px; left: 28px;
    width: 42px; height: 42px;
    background: rgba(0,194,168,0.15);
    border: 1px solid rgba(0,194,168,0.3);
    border-radius: 8px;
    display: flex; align-items: center; justify-content: center;
    cursor: pointer;
    color: var(--teal);
    font-size: 1.1rem;
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s;
    z-index: 500;
}
#scrollTop.visible { opacity: 1; pointer-events: all; }
#scrollTop:hover { background: rgba(0,194,168,0.25); }

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 1080px) {
    .hero-inner { grid-template-columns: 1fr; text-align: center; }
    .hero-content { max-width: 100%; }
    .hero-role { justify-content: center; }
    .hero-btns { justify-content: center; }
    .hero-stats { justify-content: center; }
    .hero-visual { margin-top: 40px; }
    .stat-item { align-items: center; }
}
@media (max-width: 900px) {
    .about-grid, .contact-grid { grid-template-columns: 1fr; }
    nav ul { display: none; }
    .hamburger { display: flex; }
    .chip-1, .chip-2, .chip-3 { display: none; }
    .timeline::before { left: 12px; }
    .timeline-item { padding-left: 40px; }
    .timeline-dot { left: 5px; }
}
@media (max-width: 600px) {
    section { padding: 72px 5%; }
    .hero { padding: 90px 5% 80px; }
    .hero-stats { flex-wrap: wrap; }
    .pub-item { grid-template-columns: 1fr; gap: 10px; }
    .pub-year { font-size: 1.2rem; }
    footer { flex-direction: column; text-align: center; }
    .profile-card { width: 260px; }
    .profile-img-wrapper { height: 300px; }
    .float-badge, .profile-ring { display: none; }
    .timeline-header { flex-direction: column; }
}