* { box-sizing: border-box; }

html,
body {
    margin: 0;
    min-height: 100%;
}

body {
    background:
        radial-gradient(circle at 20% 0%, #252525 0, transparent 35%),
        radial-gradient(circle at 90% 100%, #201b0e 0, transparent 30%),
        #090909;
    color: #f4f4f4;
    font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,.018) 1px, transparent 1px);
    background-size: 40px 40px;
}

.app {
    width: min(1240px, calc(100% - 32px));
    margin: 0 auto;
    padding: 32px 0 50px;
}

.topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid rgba(255,255,255,.10);
    padding-bottom: 22px;
    margin-bottom: 38px;
}

.eyebrow {
    color: #c9a653;
    letter-spacing: .28em;
    font-size: 11px;
    font-weight: 700;
}

h1 {
    margin: 6px 0 0;
    font-size: clamp(24px, 3vw, 38px);
    letter-spacing: .04em;
}

.version {
    border: 1px solid rgba(201,166,83,.45);
    color: #d3b465;
    padding: 9px 12px;
    font-size: 11px;
    letter-spacing: .15em;
}

.hero {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 40px;
    align-items: end;
    margin-bottom: 30px;
}

.hero-copy > span {
    color: #c9a653;
    font-size: 11px;
    letter-spacing: .18em;
}

.hero-copy h2 {
    margin: 8px 0 8px;
    font-size: clamp(28px, 5vw, 52px);
    line-height: 1;
}

.hero-copy p {
    max-width: 720px;
    margin: 0;
    color: #a8a8a8;
    line-height: 1.65;
}

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

.control-card {
    display: grid;
    grid-template-columns: auto auto;
    gap: 5px;
    border: 1px solid rgba(255,255,255,.12);
    background: rgba(255,255,255,.035);
    padding: 12px;
}

.control-card strong {
    grid-column: 1 / -1;
    color: #aaa;
    font-size: 10px;
    letter-spacing: .12em;
    margin-bottom: 4px;
}

.control-card span {
    display: grid;
    place-items: center;
    min-width: 34px;
    height: 34px;
    border: 1px solid rgba(255,255,255,.15);
    font-weight: 800;
}

.versus {
    color: #575757;
    font-size: 12px;
    font-weight: 800;
}

.arena-shell {
    overflow: hidden;
    border: 1px solid rgba(255,255,255,.12);
    background: rgba(255,255,255,.025);
    box-shadow: 0 35px 100px rgba(0,0,0,.45);
}

#game-container {
    width: 100%;
    background: #101010;
}

#game-container canvas {
    display: block;
    margin: auto;
    max-width: 100%;
}

.arena-footer {
    min-height: 84px;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 20px;
    border-top: 1px solid rgba(255,255,255,.10);
    padding: 16px 24px;
}

.arena-footer > div:last-child {
    text-align: right;
}

.arena-footer small {
    display: block;
    margin-bottom: 3px;
    color: #686868;
    font-size: 9px;
    letter-spacing: .18em;
}

.arena-footer strong {
    font-size: 11px;
    letter-spacing: .12em;
}

#start-button {
    appearance: none;
    border: 1px solid #d0ad57;
    background: #d0ad57;
    color: #101010;
    min-width: 200px;
    min-height: 46px;
    padding: 0 22px;
    cursor: pointer;
    font-size: 11px;
    font-weight: 900;
    letter-spacing: .13em;
    transition: transform .15s ease, background .15s ease;
}

#start-button:hover {
    transform: translateY(-1px);
    background: #e0bf6b;
}

@media (max-width: 760px) {
    .app {
        width: min(100% - 20px, 1240px);
        padding-top: 18px;
    }

    .hero {
        grid-template-columns: 1fr;
    }

    .controls {
        justify-content: space-between;
    }

    .arena-footer {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .arena-footer > div:last-child {
        text-align: center;
    }

    #start-button {
        order: -1;
        width: 100%;
    }
}