:root {
    --bg: #0f172a;
    --card: #111827;
    --ink: #e5e7eb;
    --accent: #38bdf8;
    --accent-2: #a78bfa;
    --good: #22c55e;
    --bad: #ef4444;
}

* {
    box-sizing: border-box
}

body {
    margin: 0;
    font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    background: radial-gradient(1200px 800px at 20% -10%, #1e293b, transparent 60%),
        radial-gradient(1200px 800px at 120% 110%, #1f2937, transparent 60%),
        var(--bg);
    color: var(--ink);
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
    overflow-x:hidden ;
}

.top {
    position: absolute;
    top: 10px;
    left: 10px;
}

.top img {
    height: 40px;
    padding: 5px;
    margin: 5px;
}

.app {
    width: min(980px, 96vw);
    display: grid;
    gap: 20px;
}

header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap
}

h1 {
    font-size: clamp(1.25rem, 2.2vw + 1rem, 2rem);
    margin: 0;
    letter-spacing: .5px
}

.controls {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap
}

.pill {
    background: #0b1220;
    border: 1px solid #20304a;
    color: var(--ink);
    padding: 8px 12px;
    border-radius: 999px;
    font-weight: 600
}

.btn {
    cursor: pointer;
    border: 0;
    border-radius: 12px;
    padding: 10px 14px;
    font-weight: 700;
    color: #0b1220;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
}

.btn:active {
    transform: translateY(1px)
}

.grid {
    --cols: 2;
    display: grid;
    gap: 14px;
    grid-template-columns: repeat(var(--cols), 1fr)
}

@media (min-width: 480px) {
    .grid {
        --cols: 3
    }
}

@media (min-width: 740px) {
    .grid {
        --cols: 6
    }
}

@media (min-width: 1020px) {
    .grid {
        --cols: 8
    }
}

.card {
    aspect-ratio: 3 / 4;
    perspective: 900px;
    border-radius: 16px;
    position: relative;
    user-select: none;
    outline: none;
}

.face {
    position: absolute;
    inset: 0;
    display: grid;
    place-items: center;
    border-radius: 16px;
    backface-visibility: hidden;
    transition: transform .5s ease, box-shadow .2s ease;
    box-shadow: 0 6px 18px rgba(0, 0, 0, .35), inset 0 0 0 1px rgba(255, 255, 255, .04)
}

.front {
    background: linear-gradient(180deg, #0b1220, #111827);
    border: 1px solid #1f2a44;
    transform: rotateY(0deg);
}

.back {
    background: radial-gradient(120px 160px at 20% 20%, rgba(255, 255, 255, .06), transparent 60%), #0f172a;
    border: 1px solid #23304f;
    transform: rotateY(180deg);
    font-size: clamp(1.2rem, 2.2vw + .6rem, 2.4rem);
    font-weight: 800;
    letter-spacing: .5px;
    color: var(--ink)
}

.card[data-flipped="true"] .front {
    transform: rotateY(-180deg)
}

.card[data-flipped="true"] .back {
    transform: rotateY(0deg)
}

.card.matched .back {
    border-color: rgba(34, 197, 94, .6);
    box-shadow: 0 0 0 2px rgba(34, 197, 94, .45) inset
}

.card:not(.matched):focus-visible {
    box-shadow: 0 0 0 3px rgba(56, 189, 248, .65)
}

.footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap
}

.range {
    display: flex;
    align-items: center;
    gap: 10px
}

input[type=range] {
    accent-color: var(--accent);
    width: 100%;
    max-width: 220px
}

.toast {
    position: fixed;
    left: 50%;
    bottom: 24px;
    transform: translateX(-50%);
    padding: 10px 14px;
    border-radius: 999px;
    background: #0b1220;
    border: 1px solid #263656;
    font-weight: 700
}

dialog {
    border: 0;
    border-radius: 20px;
    background: #0b1220;
    color: var(--ink);
    padding: 24px 20px;
    max-width: 420px;
    width: 90%;
}

dialog::backdrop {
    background: rgba(0, 0, 0, .6)
}