:root{
    --bg: #098684;
    --panel: #c0c0c0;
    --panel-mid: #b3b2b2;
    --panel-light: #ffffff;
    --panel-dark: #7b7b7b;
    --panel-deep: #1e1d1d;
    --text: #000000;
    --muted: #404040;
    --field-alt: #0f0f0f;
    --lane-divider: #2f2f2f;
    --lane-1: #4f83ff;
    --lane-1-bright: #93c4ff;
    --lane-2: #35d4ff;
    --lane-2-bright: #9df0ff;
    --lane-3: #ff64be;
    --lane-3-bright: #ffaad9;
    --lane-4: #d74bff;
    --lane-4-bright: #efabff;
    --perfect: #f2ffff;
    --great: #55cf7b;
    --good: #d7ac22;
    --miss: #c53545;
    --receptor-height: 64px;
    --judgement-line-offset: 86px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    border-radius: 0 !important;
}

[hidden] {
    display: none !important;
}

[hidden]::before, [hidden]::after {
    content: none !important;
}
html, body {
    width: 100%;
    min-height: 100%;
}

body {
    width: 100%;
    min-height: 100vh;
    font: 13px "MS Sans Serif", Tahoma, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

#intro-screen {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: black;
        display: flex;
        justify-content: center;
        align-items: center;
        z-index: 9999;
        animation: fadeOut 1s ease-in-out 3s forwards; 
        pointer-events: none; 
    }

    
#intro-logo {
    width: 200px;
    opacity: 0;
    animation: fadeInScale 2s ease-out forwards;
}

@keyframes fadeInScale {
    0% { opacity: 0; transform: scale(0.5); }
    100% { opacity: 1; transform: scale(1.3); }
}

@keyframes fadeOut {
    0% { opacity: 1; }
    100% { opacity: 0; visibility: hidden; }
}

#main-menu {
    animation: fadeIn 1s ease-in 3s forwards;
    opacity: 0;
    gap: 12px;
}

@keyframes fadeIn {
    to { opacity: 1; }
}

button {
    font: inherit;
    color: var(--text);
    background: var(--panel);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
    padding: 10px 16px;
    cursor: pointer;
}

button:hover {
    background: #d4d0c8;
}

button:active {
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
    padding: 11px 15px 9px 17px;
}

button.primary {
    min-width: 200px;
}

section {
    width: min(100%, 980px);
    min-height: 100vh;
    padding: 24px 16px 28px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.screen:not([hidden]) {
    animation: screen-fade 180ms steps(1, end);
}

#main-menu, #song-select, #game-container {
    width: min(100%, 420px);
    min-height: auto;
    margin: 0;
    padding: 12px;
    background: var(--panel);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
}

#game-container {
    width: min(100%, 560px);
}   

#main-menu, #song-select, #game-container, #result-screen {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.window-title {
    width: calc(100% + 24px);
    min-height: 20px;
    margin: -12px -12px 12px;
    padding: 2px 3px 2px 6px;
    background: #000080;
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    font-weight: 700;
    line-height: 1;
}

.window-title span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.window-buttons {
    display: flex;
    align-items: center;
    gap: 2px;
    flex: 0 0 auto;
}

.window-button {
    position: relative;
    width: 18px;
    height: 16px;
    min-width: 0;
    padding: 0;
    background: var(--panel);
    color: var(--text);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
    overflow: hidden;
    line-height: 1;
}

.window-button::before, .window-button::after {
    content: "";
    position: absolute;
    background: #000000;
    pointer-events: none;
}

.window-button.is-min::before {
    left: 50%;
    top: 50%;
    width: 8px;
    height: 2px;
    transform: translate(-50%, -50%);
}

.window-button.is-max::before {
    left: 50%;
    top: 50%;
    width: 8px;
    height: 8px;
    background: transparent;
    border: 2px solid #000000;
    box-sizing: border-box;
    transform: translate(-50%, -50%);
}

.window-button.is-close::before, .window-button.is-close::after {
    left: 50%;
    top: 50%;
    width: 10px;
    height: 2px;
    transform-origin: center;
}

.window-button.is-close::before {
    transform: translate(-50%, -50%) rotate(45deg);
}

.window-button.is-close::after {
    transform: translate(-50%, -50%) rotate(-45deg);
}

.window-button:hover {
    background: #d4d0c8;
}

.window-button:focus-visible {
    outline: 1px dotted #000000;
    outline-offset: -4px;
}

.window-button:active {
    padding: 0;
    transform: translate(2px, 2px);
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
    box-shadow: inset 1px 1px 0 var(--panel-dark);
}

#main-menu .primary {
    width: 100%;
    font-size: 18px; 
}

#creditsLabel {
    max-width: 100%;
    text-align: center;
    font-size: 11px;
    line-height: 1.4;
    color: var(--muted);
}

#songsList {
    width: 100%;
    display: grid;
    gap: 8px;
}

#songsList button {
    width: 100%;
    padding: 10px;
    text-align: left;
    display: grid;
    gap: 4px;
    background: var(--panel-mid);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
}

#songsList button:hover {
    background: #000080;
    color: #ffffff;
}

#songsList strong {
    font-size: 14px;
    font-weight: 700;
}

#game-container {
    justify-content: center;
    width: min(100%, 560px);
    margin: 0;
    min-height: auto;
}

#game-stage {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    margin: 0 auto;
}

#hud, #playfield-shell {
    background: var(--panel);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
}

#hud {
    width: min(100%, 444px);
    padding: 6px;
    text-align: center;
}

#hud small, #comboWrap small, .results-card small, .results-stat span {
    display: block;
    color: var(--muted);
    line-height: 1.1;
}

#score {
    display: inline-block;
    min-width: 216px;
    margin-top: 4px;
    padding: 6px 10px;
    background: #000000;
    color: #00ff66;
    font: 700 24px "Lucida Console", "Courier New", monospace;
    letter-spacing: 0.08em;
    border: 2px solid var(--panel-dark);
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
}

#playfield-shell {
    position: relative;
    width: min(100%, 444px);
    padding: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

#comboWrap {
    position: absolute;
    left: 50%;
    top: 42%;
    transform: translate(-50%, -50%);
    z-index: 7;
    padding: 6px 10px;
    background: var(--panel);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
    text-align: center;
    pointer-events: none;
}

#comboWrap.pulse {
    animation: combo-pulse 140ms steps(2, end);
}

#combo {
    font: 700 28px "Lucida Console", "Courier New", monospace;
    line-height: 1;
    letter-spacing: 0.05em;
}

#lane-frame {
    position: relative;
    width: 100%;
    aspect-ratio: 4 / 5.6;
    background: var(--panel-dark);
    border: 2px solid var(--panel-dark);
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
    overflow: hidden;
}

#lane-frame::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: calc(var(--judgement-line-offset) + 8px);
    z-index: 4;
    pointer-events: none;
    background: linear-gradient(to bottom, rgba(15, 15, 15, 0) 0%, rgba(8, 8, 8, 0.28) 42%, rgba(0, 0, 0, 0.82) 78%, #000000 100%);
}

#lane-grid, #gameCanvas, #judgement-line, #judgement {
    position: absolute;
    inset: 0;
}

#lane-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    background: var(--field-alt);
    overflow: hidden;
}

.lane {
    position: relative;
    min-width: 0;
}

.lane + .lane {
    border-left: 1px solid var(--lane-divider);
}

.lane::before {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    
}

.lane.lane-1::before {
    background: rgba(79, 131, 255, 0.08);
}

.lane.lane-2::before {
    background: rgba(53, 212, 255, 0.08);
}

.lane.lane-3::before {
    background: rgba(255, 100, 190, 0.08)
}

.lane.lane-4::before {
    background: rgba(215, 75, 255, 0.08)
}

#gameCanvas {
    z-index: 3;
    width: 100%;
    height: 100%;
}

#judgement-line {
    top: auto;
    bottom: var(--judgement-line-offset);
    height: 3px;
    z-index: 5;
    background: #f5f5f5;
    border-top: 1px solid #ffffff;
    border-bottom: 1px solid #1e1d1d;
    pointer-events: none;
}

#judgement {
    inset: auto 0 calc(var(--judgement-line-offset) + 20px) 0;
    height: 42px;
    z-index: 6;
    display: grid;
    place-items: center;
    font: 700 22px "MS Sans Serif", Tahoma, Arial, sans-serif;
    opacity: 0;
    pointer-events: none;
}

#judgement.show {
    animation: judgement-pop 240ms linear forwards;
}

#judgement[data-judgement="PERFECT"] {
    color: var(--perfect);
}

#judgement[data-judgement="GREAT"] {
    color: var(--great);
}

#judgement[data-judgement="GOOD"] {
    color: var(--good);
}

#judgement[data-judgement="MISS"] {
    color: var(--miss);
}

#error-bar {
    position: relative;
    width: 100%;
    height: 34px;
    background: var(--panel-mid);
    border: 2px solid var(--panel-dark);
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
    overflow: hidden;
}

#error-bar-labels {
    position: absolute;
    inset: 2px 4px auto 4px;
    height: 10px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 9px;
    color: var(--muted);
    pointer-events: none;
    z-index: 4;
}

.error-bar-label {
    padding: 0 3px;
    background: rgba(192, 192, 192, 0.92);
    line-height: 1;
}

#error-lane-grid {
    position: absolute;
    inset: 12px 2px 2px 2px;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    z-index: 1;
}

.error-lane {
    position: relative;
    min-width: 0;
    background: #b9b9b9;
    --meter-scale: 0.12;
    --meter-opacity: 0.18;
}

.error-lane + .error-lane {
    border-left: 1px solid var(--panel-dark);
}

.error-lane::before {
    content: "";
    position: absolute;
    inset: 0;
    opacity: 0.12;
    pointer-events: none;
}

.error-lane.lane-1::before {
    background: rgba(79, 131, 255, 0.22);
}

.error-lane.lane-2::before {
    background: rgba(53, 212, 255, 0.22);
}

.error-lane.lane-3::before {
    background: rgba(255, 100, 190, 0.22);
}

.error-lane.lane-4::before {
    background: rgba(215, 75, 255, 0.22)
}

.error-lane::after {
    content: "";
    position: absolute;
    top: 2px;
    left: 50%;
    width: 10px;
    height: 4px;
    transform: translateX(-50%);
    background: #8c8c8c;
    border: 1px solid var(--panel-dark);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
    pointer-events: none;
}

.error-lane-meter {
    position: absolute;
    left: 2px;
    right: 2px;
    bottom: 2px;
    height: 7px;
    transform-origin: left center;
    transform: scaleX(var(--meter-scale));
    opacity: var(--meter-opacity);
    transition: transform 60ms linear, opacity 60ms linear, height 60ms linear, background 60ms linear;
}

.error-lane.lane-1 .error-lane-meter {
    background: var(--lane-1);
}

.error-lane.lane-2 .error-lane-meter {
    background: var(--lane-2);
}

.error-lane.lane-3 .error-lane-meter {
    background: var(--lane-3)
}

.error-lane.lane-4 .error-lane-meter {
    background: var(--lane-4)
}

.error-lane.active .error-lane-meter {
    height: 9px;
    opacity: 0.8;
}

.error-lane.holding .error-lane-meter {
    height: 11px;
    opacity: 0.92;
}

.error-lane.active::after, .error-lane.holding::after {
    border-top-color: var(--panel-light);
    border-left-color: var(--panel-light);
}

.error-lane.lane-1.active::after, .error-lane.lane-1.holding::after {
    background: var(--lane-1-bright);
}

.error-lane.lane-2.active::after, .error-lane.lane-2.holding::after {
    background: var(--lane-2-bright);
}

.error-lane.lane-3.active::after, .error-lane.lane-3.holding::after {
    background: var(--lane-3-bright);
}

.error-lane.lane-4.active::after, .error-lane.lane-4.holding::after {
    background: var(--lane-4-bright);
}

.error-lane.flash[data-judgement="PERFECT"] .error-lane-meter, .error-lane.flash[data-judgement="PERFECT"]::after {
    background: var(--perfect);
}

.error-lane.flash[data-judgement="GREAT"] .error-lane-meter, .error-lane.flash[data-judgement="GREAT"]::after {
    background: var(--great);
}

.error-lane.flash[data-judgement="GOOD"] .error-lane-meter, .error-lane.flash[data-judgement="GOOD"]::after {
    background: var(--good);
}

.error-lane.flash[data-judgement="MISS"] .error-lane-meter, .error-lane.flash[data-judgement="MISS"]::after {
    background: var(--miss);
}

#error-bar-center {
    position: absolute;
    top: 1px;
    bottom: 2px;
    left: 50%;
    width: 1px;
    transform: translateX(-50%);
    background: #000000;
    z-index: 3;
}

#errorMarkers {
    position: absolute;
    inset: 12px 0 0 0;
    z-index: 5;
}

.error-marker {
    position: absolute;
    top: 0;
    width: 3px;
    height: 18px;
    margin-left: -1.5px;
    background: currentColor;
    border: 1px solid rgba(0, 0, 0, 0.35);
    opacity: 0;
    animation: error-fade 900ms linear forwards;
}

.error-marker[data-judgement="PERFECT"] {
    color: var(--perfect)
}

.error-marker[data-judgement="GREAT"] {
    color: var(--great)
}

.error-marker[data-judgement="GOOD"] {
    color: var(--good)
}

.error-marker[data-judgement="MISS"] {
    color: var(--miss)
}

#keys {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    background: var(--panel-mid);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep); 
    overflow: hidden;
}

.key-slot {
    position: relative;
    height: var(--receptor-height);
    display: grid;
    place-items: center;
    font: 700 22px "MS Sans Serif", Tahoma, Arial, sans-serif;
    color: var(--text);
    background: var(--panel);
    box-shadow: inset 1px 1px 0 #ffffff, inset -1px -1px 0 var(--panel-dark);
    transition: transform 50ms linear, background 50ms linear, color 50ms linear, box-shadow 50ms linear;
}

.key-slot + .key-slot {
    border-left: 1px solid var(--panel-dark);
}

.key-slot::before {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: 0.14;
}

.key-slot.lane-1::before {
    background: rgba(79, 131, 255, 0.18);
}

.key-slot.lane-2::before {
    background: rgba(53, 212, 255, 0.18);
}

.key-slot.lane-3::before {
    background: rgba(255, 100, 190, 0.18);
}

.key-slot.lane-4::before {
    background: rgba(215, 75, 255, 0.18);
}

.key-slot.active {
    transform: translate(1px, 1px);
    box-shadow: inset 1px 1px 0 var(--panel-dark), inset -1px -1px 0 #ffffff;
}

.key-slot.lane-1.active {
    background: #b9ccf0;
    color: #153c92;
}

.key-slot.lane-2.active {
    background: #b7e5f0;
    color: #0c6377;
}

.key-slot.lane-3.active {
    background: #efbad8;
    color: #8f2358;
}

.key-slot.lane-4.active {
    background: #d9b8ef;
    color: #6f2790;
}

#results-screen {
    width: min(100%, 420px);
    min-height: auto;
    margin: 0;
    padding: 0;
    justify-content: center;
}


.results-card {
    width: 100%;
    padding: 12px;
    background: var(--panel);
    border: 2px solid var(--panel-light);
    border-right-color: var(--panel-deep);
    border-bottom-color: var(--panel-deep);
    display: grid;
    gap: 10px;
}

.results-card > .window-title {
    margin: -12px -12px 0;
}

.result-stat {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background: var(--panel-mid);
    border: 2px solid var(--panel-dark);
    border-top-color: var(--panel-deep);
    border-left-color: var(--panel-deep);
    border-right-color: var(--panel-light);
    border-bottom-color: var(--panel-light);
}

.result-stat strong {
    font: 700 22px "Lucida Console", "Courier New", monospace;
    letter-spacing: 0.04em;
}

@keyframes screen-fade {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes judgement-pop {
    0% {
        opacity: 0;
        transform: translateY(8px);
    }

    30% {
        opacity: 1;
        transform: translateY(0);
    }

    100% {
        opacity: 0;
        transform: translateY(-10px);
    }
}

@keyframes combo-pulse {
    0% {
        transform: translate(-50%, -50%);
    }

    50% {
        transform: translate(-50%, -50%) scale(1.04);
    }

    100% {
        transform: translate(-50%, -50%);
    }
}

@keyframes error-fade {
    0% {
        opacity: 1; transform: translateY(0);
    }

    100% {
        opacity: 0;
        transform: translateY(-4px);
    }
}

@media (max-width: 640px) {
    body {
        overflow-y: auto;
    }

    section {
        padding: 16px 12px 20px;
    }

    #hud, #playfield-shell {
        width: min(100%, 380px);
    }

    #score {
        min-width: 188px;
        font-size: 20px;
    }

    #combo {
        font-size: 24px;
    }

    #judgement {
        font-size: 18px;
    }

    .key-slot {
        font-size: 20px
    }
}