/* ===========================================================
   Amanpreet Kapoor — modern dark + gradient design system
   Themeable via :root.dark / :root.light (toggle in nav).
   Layout still uses Tailwind utilities; this file owns the look.
   =========================================================== */

:root.dark {
    --bg: #070b16;
    --surface: rgba(255, 255, 255, 0.045);
    --surface-2: rgba(255, 255, 255, 0.03);
    --border: rgba(255, 255, 255, 0.09);
    --border-strong: rgba(255, 255, 255, 0.16);
    --text: #d7e0ef;
    --muted: #92a0b8;
    --heading: #f4f7fc;
    --accent: #5b8cff;
    --accent-2: #22d3ee;
    --accent-3: #a78bfa;
    --nav-bg: rgba(9, 13, 25, 0.72);
    --shadow: 0 24px 55px -28px rgba(0, 0, 0, 0.85);
    --card-hover-shadow: 0 30px 70px -25px rgba(20, 60, 160, 0.55);
    --glow-1: rgba(79, 124, 255, 0.20);
    --glow-2: rgba(34, 211, 238, 0.14);
    --glow-3: rgba(139, 92, 246, 0.14);
}

:root.light {
    --bg: #eef2f9;
    --surface: #ffffff;
    --surface-2: #f6f9fd;
    --border: rgba(2, 33, 165, 0.10);
    --border-strong: rgba(2, 33, 165, 0.20);
    --text: #3a4658;
    --muted: #64748b;
    --heading: #0f1f4b;
    --accent: #0021A5;
    --accent-2: #2563eb;
    --accent-3: #7c3aed;
    --nav-bg: rgba(255, 255, 255, 0.78);
    --shadow: 0 18px 42px -26px rgba(15, 31, 75, 0.40);
    --card-hover-shadow: 0 26px 55px -24px rgba(2, 33, 165, 0.30);
    --glow-1: rgba(79, 124, 255, 0.14);
    --glow-2: rgba(34, 211, 238, 0.08);
    --glow-3: rgba(139, 92, 246, 0.08);
}

* { -webkit-tap-highlight-color: transparent; }

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    min-height: 100vh;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* Ambient gradient glows behind everything */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    background:
        radial-gradient(650px circle at 12% -5%, var(--glow-1), transparent 46%),
        radial-gradient(750px circle at 105% 8%, var(--glow-2), transparent 42%),
        radial-gradient(700px circle at 50% 110%, var(--glow-3), transparent 48%);
    transition: opacity 0.4s ease;
}

/* ---------- Text helpers ---------- */
.gradient-text {
    background: linear-gradient(120deg, var(--accent), var(--accent-2) 55%, var(--accent-3));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

.heading { color: var(--heading); }
.muted { color: var(--muted); }

.link {
    color: var(--accent-2);
    text-decoration: none;
    background-image: linear-gradient(var(--accent-2), var(--accent-2));
    background-size: 0% 2px;
    background-repeat: no-repeat;
    background-position: 0 100%;
    transition: background-size 0.3s ease, color 0.2s ease;
    font-weight: 500;
}
.link:hover {
    color: var(--accent);
    background-size: 100% 2px;
}

/* ---------- Top accent line ---------- */
.accent-line {
    height: 3px;
    background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
    background-size: 200% 100%;
    animation: shimmer 8s linear infinite;
}
@keyframes shimmer {
    to { background-position: 200% 0; }
}

/* ---------- Navigation ---------- */
.nav-bar {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--nav-bg);
    backdrop-filter: blur(14px) saturate(140%);
    -webkit-backdrop-filter: blur(14px) saturate(140%);
    border-bottom: 1px solid var(--border);
}
.brand {
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.01em;
    transition: opacity 0.2s ease;
}
.brand:hover { opacity: 0.82; }

.nav-item {
    position: relative;
    color: var(--muted);
    padding: 0.5rem 1rem;
    border-radius: 0.6rem;
    font-size: 0.875rem;
    font-weight: 500;
    transition: color 0.2s ease, background-color 0.2s ease;
}
.nav-item:hover { color: var(--heading); }
.nav-item::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 0.15rem;
    width: 0;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    transition: width 0.3s ease, left 0.3s ease;
}
.nav-item:hover::after { width: 60%; left: 20%; }
.nav-item.active {
    color: var(--heading);
    background: color-mix(in srgb, var(--accent) 16%, transparent);
}
.nav-item.active::after { width: 60%; left: 20%; }

.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 0.7rem;
    color: var(--heading);
    background: var(--surface);
    border: 1px solid var(--border);
    transition: transform 0.25s ease, background-color 0.2s ease, border-color 0.2s ease;
}
.theme-toggle:hover {
    transform: rotate(-15deg) scale(1.05);
    border-color: var(--border-strong);
    background: color-mix(in srgb, var(--accent) 14%, transparent);
}
/* Show the icon of the theme you can switch TO; toggled purely via CSS
   so it works even after Font Awesome swaps the <i> for an <svg>. */
.theme-icon-sun, .theme-icon-moon { display: none; }
:root.dark .theme-icon-sun { display: inline-block; }
:root.light .theme-icon-moon { display: inline-block; }

.icon-btn {
    color: var(--muted);
    border-radius: 0.6rem;
    padding: 0.5rem;
    transition: color 0.2s ease, background-color 0.2s ease;
}
.icon-btn:hover { color: var(--heading); background: var(--surface); }

.mobile-item {
    display: block;
    color: var(--muted);
    padding: 0.55rem 0.75rem;
    border-radius: 0.6rem;
    font-weight: 500;
    transition: color 0.2s ease, background-color 0.2s ease;
}
.mobile-item:hover { color: var(--heading); background: var(--surface); }
.mobile-item.active {
    color: var(--heading);
    background: color-mix(in srgb, var(--accent) 16%, transparent);
}
.mobile-panel {
    background: var(--nav-bg);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-top: 1px solid var(--border);
}

/* ---------- Glass cards ---------- */
.glass {
    position: relative;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 1.25rem;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: var(--shadow);
    transition: transform 0.35s ease, box-shadow 0.35s ease, border-color 0.35s ease;
}
.glass-hover:hover {
    transform: translateY(-3px);
    border-color: var(--border-strong);
    box-shadow: var(--card-hover-shadow);
}

/* ---------- Section titles ---------- */
.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading);
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

/* Rounded gradient icon badge for section titles */
.card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.75rem;
    height: 2.75rem;
    border-radius: 0.85rem;
    font-size: 1.1rem;
    flex-shrink: 0;
    border: 1px solid transparent;
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.card-title:hover .card-icon { transform: translateY(-2px) rotate(-4deg); }

.card-icon.i-blue   { color: #60a5fa; background: linear-gradient(135deg, rgba(59,130,246,0.22), rgba(59,130,246,0.08)); border-color: rgba(59,130,246,0.30); box-shadow: 0 8px 20px -10px rgba(59,130,246,0.6); }
.card-icon.i-green  { color: #34d399; background: linear-gradient(135deg, rgba(16,185,129,0.22), rgba(16,185,129,0.08)); border-color: rgba(16,185,129,0.30); box-shadow: 0 8px 20px -10px rgba(16,185,129,0.6); }
.card-icon.i-orange { color: #fb923c; background: linear-gradient(135deg, rgba(249,115,22,0.22), rgba(249,115,22,0.08)); border-color: rgba(249,115,22,0.30); box-shadow: 0 8px 20px -10px rgba(249,115,22,0.6); }
.card-icon.i-amber  { color: #fbbf24; background: linear-gradient(135deg, rgba(245,158,11,0.22), rgba(245,158,11,0.08)); border-color: rgba(245,158,11,0.30); box-shadow: 0 8px 20px -10px rgba(245,158,11,0.6); }

:root.light .card-icon.i-blue   { color: #2563eb; }
:root.light .card-icon.i-green  { color: #059669; }
:root.light .card-icon.i-orange { color: #ea580c; }
:root.light .card-icon.i-amber  { color: #d97706; }
.section-title {
    text-align: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading);
    padding-bottom: 0.9rem;
    margin-bottom: 2rem;
    position: relative;
}
.section-title::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 0;
    transform: translateX(-50%);
    width: 72px;
    height: 3px;
    border-radius: 3px;
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
}
.section-title.amber::after { background: linear-gradient(90deg, #f59e0b, #fbbf24); }
.section-title.green::after { background: linear-gradient(90deg, #10b981, #34d399); }
.section-title.orange::after { background: linear-gradient(90deg, #f97316, #fb923c); }

/* ---------- Publication / list items ---------- */
.pub {
    position: relative;
    padding: 0.35rem 0 0.35rem 1.5rem;
    transition: transform 0.25s ease;
}
.pub::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.35rem;
    bottom: 0.35rem;
    width: 3px;
    border-radius: 3px;
    background: linear-gradient(180deg, var(--accent), var(--accent-2));
    opacity: 0.85;
}
.pub:hover { transform: translateX(5px); }
.pub--amber::before { background: linear-gradient(180deg, #f59e0b, #fbbf24); }
.pub--green::before { background: linear-gradient(180deg, #10b981, #34d399); }
.pub--orange::before { background: linear-gradient(180deg, #f97316, #fb923c); }

.pub-title {
    font-size: 1.05rem;
    font-weight: 600;
    line-height: 1.45;
    margin-bottom: 0.5rem;
    color: var(--heading);
}
.pub-authors { color: var(--text); margin-bottom: 0.25rem; }
.pub-venue { color: var(--muted); margin-bottom: 0.75rem; }
.pub-note { color: var(--muted); font-size: 0.85rem; margin-top: 0.5rem; }

/* ---------- Tags (resource pills) ---------- */
.tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.tag {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.32rem 0.75rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid transparent;
    transition: transform 0.15s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}
.tag:hover { transform: translateY(-2px); }

.tag-blue   { color: #60a5fa; background: rgba(59, 130, 246, 0.14); border-color: rgba(59, 130, 246, 0.28); }
.tag-green  { color: #34d399; background: rgba(16, 185, 129, 0.14); border-color: rgba(16, 185, 129, 0.28); }
.tag-red    { color: #f87171; background: rgba(239, 68, 68, 0.14);  border-color: rgba(239, 68, 68, 0.28); }
.tag-orange { color: #fb923c; background: rgba(249, 115, 22, 0.14); border-color: rgba(249, 115, 22, 0.28); }
.tag-gray   { color: #cbd5e1; background: rgba(148, 163, 184, 0.14); border-color: rgba(148, 163, 184, 0.30); }
.tag:hover.tag-blue   { box-shadow: 0 6px 18px -8px rgba(59, 130, 246, 0.6); }
.tag:hover.tag-green  { box-shadow: 0 6px 18px -8px rgba(16, 185, 129, 0.6); }
.tag:hover.tag-red    { box-shadow: 0 6px 18px -8px rgba(239, 68, 68, 0.6); }
.tag:hover.tag-orange { box-shadow: 0 6px 18px -8px rgba(249, 115, 22, 0.6); }

:root.light .tag-blue   { color: #1d4ed8; background: rgba(59, 130, 246, 0.10); }
:root.light .tag-green  { color: #047857; background: rgba(16, 185, 129, 0.10); }
:root.light .tag-red    { color: #b91c1c; background: rgba(239, 68, 68, 0.10); }
:root.light .tag-orange { color: #c2410c; background: rgba(249, 115, 22, 0.10); }
:root.light .tag-gray   { color: #475569; background: rgba(148, 163, 184, 0.16); }

/* ---------- Quick-nav chips ---------- */
.chip {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 1rem;
    border-radius: 0.7rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    background: var(--surface);
    border: 1px solid var(--border);
    transition: transform 0.2s ease, color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}
.chip:hover {
    transform: translateY(-2px);
    color: var(--heading);
    border-color: var(--border-strong);
}
.chip.c-blue:hover   { background: rgba(59, 130, 246, 0.14);  border-color: rgba(59, 130, 246, 0.4); }
.chip.c-green:hover  { background: rgba(16, 185, 129, 0.14);  border-color: rgba(16, 185, 129, 0.4); }
.chip.c-orange:hover { background: rgba(249, 115, 22, 0.14);  border-color: rgba(249, 115, 22, 0.4); }
.chip.c-amber:hover  { background: rgba(245, 158, 11, 0.14);  border-color: rgba(245, 158, 11, 0.4); }

/* ---------- Callout boxes ---------- */
.callout {
    border-left: 3px solid var(--accent);
    background: var(--surface-2);
    border-radius: 0 0.75rem 0.75rem 0;
    padding: 1rem 1.15rem;
}
.callout h3 { color: var(--heading); font-weight: 700; margin-bottom: 0.4rem; }
.callout p { color: var(--text); }
.callout.c-blue   { border-left-color: #3b82f6; }
.callout.c-green  { border-left-color: #10b981; }
.callout.c-amber  { border-left-color: #f59e0b; }
.callout.c-red    { border-left-color: #ef4444; }
.callout.c-orange { border-left-color: #f97316; }
.callout.c-gray   { border-left-color: #94a3b8; }

/* ---------- Bio list bullets ---------- */
.bullet-list { display: flex; flex-direction: column; gap: 0.55rem; }
.bullet-list li { display: flex; align-items: flex-start; color: var(--text); }
.bullet-list .dot {
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 999px;
    margin-top: 0.5rem;
    margin-right: 0.75rem;
    flex-shrink: 0;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.bullet-list .dot.green  { background: linear-gradient(135deg, #10b981, #34d399); }
.bullet-list .dot.orange { background: linear-gradient(135deg, #f97316, #fb923c); }

/* ---------- Profile card ---------- */
.profile-ring {
    position: relative;
    width: 9rem;
    height: 9rem;
    margin: 0 auto 1rem;
    border-radius: 999px;
    padding: 3px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2), var(--accent-3));
    box-shadow: 0 0 40px -8px color-mix(in srgb, var(--accent) 60%, transparent);
}
.profile-ring img {
    width: 100%;
    height: 100%;
    border-radius: 999px;
    object-fit: cover;
    background: var(--bg);
    display: block;
}

.social {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 0.7rem;
    color: var(--muted);
    background: var(--surface);
    border: 1px solid var(--border);
    transition: transform 0.2s ease, color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}
.social:hover {
    transform: translateY(-3px);
    color: #fff;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    border-color: transparent;
    box-shadow: 0 10px 24px -10px color-mix(in srgb, var(--accent) 70%, transparent);
}

.btn-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.7rem 1.4rem;
    border-radius: 0.75rem;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(120deg, var(--accent), var(--accent-2));
    box-shadow: 0 12px 30px -12px color-mix(in srgb, var(--accent) 75%, transparent);
    transition: transform 0.2s ease, box-shadow 0.2s ease, filter 0.2s ease;
}
.btn-cta:hover {
    transform: translateY(-2px);
    filter: brightness(1.05);
    box-shadow: 0 18px 40px -12px color-mix(in srgb, var(--accent) 85%, transparent);
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 0.85rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-transform: uppercase;
    color: var(--accent-2);
    background: color-mix(in srgb, var(--accent) 12%, transparent);
    border: 1px solid var(--border);
}

/* ---------- Footer ---------- */
.site-footer {
    margin-top: 4rem;
    border-top: 1px solid var(--border);
    background: var(--surface-2);
    padding: 2.5rem 0;
}
.site-footer p { color: var(--muted); font-size: 0.875rem; }

/* ---------- Entrance animation ---------- */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(22px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-in {
    animation: fadeInUp 0.6s ease-out forwards;
    opacity: 0;
}
.d-1 { animation-delay: 0.08s; }
.d-2 { animation-delay: 0.18s; }
.d-3 { animation-delay: 0.28s; }
.d-4 { animation-delay: 0.38s; }

@media (prefers-reduced-motion: reduce) {
    .animate-in { animation: none; opacity: 1; }
    .accent-line { animation: none; }
    html { scroll-behavior: auto; }
}