:root {
    --bg: #0d0d10;
    --accent: #3ddc84;
    --pixel: "Courier New", Courier, ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
    color-scheme: dark;
}

* {
    box-sizing: border-box;
}

[hidden] {
    display: none !important;
}

html, body {
    margin: 0;
    min-height: 100%;
    background: var(--bg);
    color: var(--accent);
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 12px;
    font-family: system-ui, sans-serif;
    overscroll-behavior: none;
}

#stage {
    position: relative;
    width: min(800px, 100%, calc((100vh - 24px) * 800 / 448));
    user-select: none;
}

#snake {
    display: block;
    width: 100%;
    height: auto;
    border-radius: 12px;
    background: var(--bg);
    box-shadow: 0 0 40px color-mix(in srgb, var(--accent) 22%, transparent);
    touch-action: none;
}

#overlay {
    position: absolute;
    inset: 0;
    z-index: 3;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    overflow: auto;
    padding: 10px;
    border-radius: 12px;
    background: rgba(6, 6, 10, 0.78);
}

.panel {
    width: min(460px, 100%);
    margin: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 8px 10px;
    border-radius: 14px;
    border: 1px solid color-mix(in srgb, var(--accent) 55%, transparent);
    background: rgba(13, 13, 16, 0.92);
    box-shadow: 0 0 28px color-mix(in srgb, var(--accent) 18%, transparent);
}

h1, h2, .pixel, .big-score {
    font-family: var(--pixel);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin: 0;
    text-align: center;
    text-shadow: 0 0 12px color-mix(in srgb, var(--accent) 70%, transparent);
}

h1 { font-size: clamp(24px, 5vw, 34px); }

#modeRow button {
    padding: 4px 8px;
    font-size: 13px;
}
h2 { font-size: clamp(18px, 4vw, 26px); color: #fff; }

.big-score {
    font-size: clamp(40px, 8vw, 64px);
    letter-spacing: 0.08em;
    line-height: 1;
}

.tagline, .hint, .note, #overDetail {
    margin: 0;
    text-align: center;
    color: rgba(255, 255, 255, 0.78);
    font-size: 13px;
    line-height: 1.4;
}

.row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    width: 100%;
}

.field {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 100%;
    text-align: left;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
}

button, select {
    font-family: inherit;
    font-size: 14px;
    color: var(--accent);
    background: transparent;
    border: 1px solid color-mix(in srgb, var(--accent) 75%, #333);
    border-radius: 8px;
    padding: 6px 10px;
    cursor: pointer;
}

button:hover, select:hover {
    background: color-mix(in srgb, var(--accent) 12%, transparent);
}

button.active, button.on {
    background: color-mix(in srgb, var(--accent) 22%, transparent);
    color: #fff;
    font-weight: 650;
}

button.primary {
    width: min(280px, 100%);
    padding: 10px 16px;
    font-family: var(--pixel);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    background: var(--accent);
    color: #0d0d10;
    border-color: var(--accent);
}

button.primary:hover {
    filter: brightness(1.08);
}

button:disabled {
    opacity: 0.38;
    cursor: not-allowed;
}

button:focus-visible, select:focus-visible, input:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

select, input[type="range"] {
    width: 100%;
    background: #0d0d10;
}

input[type="range"] {
    accent-color: var(--accent);
}

#rankList, #achList {
    width: 100%;
    max-height: 240px;
    overflow: auto;
}

.rank-row, .ach {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    width: 100%;
    padding: 5px 2px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    font-family: var(--pixel);
    font-size: 13px;
    letter-spacing: 0;
    text-transform: none;
    text-shadow: none;
    color: rgba(255, 255, 255, 0.88);
}

.rank-row.me { color: var(--accent); }

.ach {
    opacity: 0.45;
    flex-direction: column;
    align-items: flex-start;
    gap: 2px;
}

.ach.got { opacity: 1; }

.ach span {
    color: rgba(255, 255, 255, 0.7);
    font-family: system-ui, sans-serif;
    font-size: 12px;
}

#pauseBtn {
    position: absolute;
    z-index: 2;
    top: 4px;
    right: 6px;
    min-width: 36px;
    padding: 2px 8px;
    background: rgba(13, 13, 16, 0.72);
}

#toast {
    position: absolute;
    z-index: 4;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    max-width: 90%;
    padding: 6px 12px;
    border-radius: 8px;
    border: 1px solid var(--accent);
    background: rgba(0, 0, 0, 0.82);
    color: #fff;
    font-family: var(--pixel);
    font-size: 13px;
    letter-spacing: 0.04em;
    text-align: center;
    pointer-events: none;
}

#dpad {
    position: absolute;
    z-index: 2;
    right: 8px;
    bottom: 8px;
    width: 132px;
    height: 132px;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    grid-template-rows: 1fr 1fr 1fr;
    gap: 4px;
    touch-action: none;
}

#dpad button {
    background: rgba(13, 13, 16, 0.55);
    font-size: 16px;
    padding: 0;
}

#dpad button[data-dir="up"] { grid-area: 1 / 2; }
#dpad button[data-dir="left"] { grid-area: 2 / 1; }
#dpad button[data-dir="down"] { grid-area: 3 / 2; }
#dpad button[data-dir="right"] { grid-area: 2 / 3; }

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

html:fullscreen,
html:-webkit-full-screen {
    background: var(--bg);
}

html:fullscreen body,
html:-webkit-full-screen body {
    padding: 0;
    height: 100%;
}

html:fullscreen #stage,
html:-webkit-full-screen #stage {
    width: min(100vw, calc(100vh * 800 / 448));
}

html:fullscreen #snake,
html:-webkit-full-screen #snake {
    border-radius: 0;
    box-shadow: none;
}

@media (max-height: 520px) {
    #dpad {
        width: 104px;
        height: 104px;
    }
}

@media (prefers-reduced-motion: reduce) {
    * {
        transition: none !important;
        animation: none !important;
    }
}