/* Base and typography /
:root {
--brand: #ef4444; / Red 500 /
--brand-dark: #dc2626; / Red 600 /
--ink: #1a202c; / Gray-900 /
--bg: #f8f9fa; / Light background /
--indigo: #4f46e5; / Indigo-600 */
}

html {
scroll-behavior: smooth;
}

body {
font-family: 'Inter', ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
background-color: var(--bg);
color: var(--ink);
}

/* Utility helpers */
.container {
max-width: 1200px;
}

.card-hover {
transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
}

.card-hover:hover {
transform: translateY(-8px);
box-shadow: 0 20px 25px -5px rgba(0,0,0,.1), 0 10px 10px -5px rgba(0,0,0,.04);
}

/* Gradients to match attached design */
.hero-gradient {
background: linear-gradient(135deg, #fff1f2 0%, #e0f2fe 100%);
}

.challenge-gradient {
background: linear-gradient(135deg, var(--indigo) 0%, var(--brand) 100%);
}

/* Buttons */
.btn-primary {
background-color: var(--brand);
color: #fff;
transition: background-color .3s ease, transform .2s ease, box-shadow .2s ease;
}

.btn-primary:hover {
background-color: var(--brand-dark);
}

.btn-secondary {
background-color: var(--ink);
color: #fff;
transition: background-color .3s ease, transform .2s ease, box-shadow .2s ease;
}

.btn-secondary:hover {
background-color: #374151; /* Gray-700 */
}

/* Nav underline hover effect */
.nav-link-hover {
position: relative;
transition: color .3s ease;
}

.nav-link-hover::after {
content: '';
position: absolute;
width: 0;
height: 2px;
bottom: -4px;
left: 50%;
transform: translateX(-50%);
background-color: var(--brand);
transition: width .3s ease-in-out;
}

.nav-link-hover:hover::after,
.nav-link-hover.active::after {
width: 60%;
}

/* Chips/filters /
.filter-chip {
border: 1px solid #e5e7eb; / gray-200 */
background: #fff;
color: var(--ink);
transition: all .2s ease;
}

.filter-chip.active {
background: var(--brand);
color: #fff;
border-color: var(--brand);
}

/* Image treatment fallbacks */
.img-cover {
width: 100%;
height: 100%;
object-fit: cover;
object-position: center;
}

/* Footer tweaks */
footer .border-top {
border-top: 1px solid rgba(255,255,255,.12);
}

/* Forms */
.input,
select,
textarea {
transition: box-shadow .2s ease, border-color .2s ease, background-color .2s ease;
}

.input:focus,
select:focus,
textarea:focus {
outline: none;
box-shadow: 0 0 0 3px rgba(239,68,68,.2);
border-color: var(--brand);
}

/* Accessibility focus visible /
:focus-visible {
outline: 3px solid rgba(79,70,229,.35); / indigo ring */
outline-offset: 2px;
}

/* Header shadow subtle enhancement */
.site-header {
box-shadow: 0 1px 0 0 rgba(0,0,0,.06);
background: rgba(255,255,255,.9);
backdrop-filter: saturate(180%) blur(6px);
}

/* Badge */
.badge {
display: inline-block;
padding: 0.25rem 0.5rem;
font-size: .75rem;
font-weight: 700;
border-radius: 9999px;
}

/* Grid helpers (optional if not using Tailwind utility) */
.grid-gap-8 {
display: grid;
gap: 2rem;
}

/* Responsive helpers */
@media (max-width: 640px) {
.hide-sm {
display: none !important;
}
}

/* Animations (optional) */
.fade-in {
animation: fade-in .4s ease both;
}

@keyframes fade-in {
from { opacity: 0; transform: translateY(6px); }
to { opacity: 1; transform: translateY(0); }
}