:root {
    --bg: #07161c;
    --number: #7fb4c0;
    --number-bright: #e8fdff;
    --accent: #8ff3ff;
    --accent-rgb: 143, 243, 255;
    --panel-rgb: 7, 22, 28;
    --scrim-rgb: 2, 8, 10;
    --shade-rgb: 0, 0, 0;
    --vignette: 0.92;
    --scan-rgb: 255, 255, 255;
    --danger: #ff8a8a;
    --danger-rgb: 255, 138, 138;
    --knob-off: #6f8c94;
    --line: rgba(var(--accent-rgb), 0.35);
    --font: "Helvetica Neue", "Avenir Next", Helvetica, Arial, sans-serif;
    color-scheme: dark;
}

/* Light theme: the same layout on a pale background with dark teal ink */
:root[data-theme="light"] {
    --bg: #e8eef0;
    --number: #3d5964;
    --number-bright: #06222c;
    --accent: #0a6a80;
    --accent-rgb: 10, 106, 128;
    --panel-rgb: 246, 249, 250;
    --scrim-rgb: 226, 234, 237;
    --shade-rgb: 8, 38, 50;
    --vignette: 0.38;
    --scan-rgb: 0, 0, 0;
    --danger: #b3261e;
    --danger-rgb: 179, 38, 30;
    --knob-off: #8fa6ae;
    color-scheme: light;
}

/* Matrix mode: black, green digits, a monospace font */
:root[data-theme="matrix"] {
    --bg: #000000;
    --number: #1fbf55;
    --number-bright: #d2ffdc;
    --accent: #00ff46;
    --accent-rgb: 0, 255, 70;
    --panel-rgb: 0, 12, 3;
    --scrim-rgb: 0, 4, 1;
    --shade-rgb: 0, 0, 0;
    --vignette: 0.95;
    --scan-rgb: 0, 255, 70;
    --danger: #ff5a4a;
    --danger-rgb: 255, 90, 74;
    --knob-off: #1c5a30;
    --font: Consolas, "Lucida Console", "SF Mono", Menlo, Monaco, "Courier New", monospace;
    color-scheme: dark;
}

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

html, body {
    width: 100%;
    height: 100%;
}

body {
    background-color: var(--bg);
    font-family: var(--font);
    overflow: hidden;
    touch-action: none;
    user-select: none;
}

/* Faint scanlines and the dark "shadow border" (vignette), above the numbers but click-through */
body::before,
body::after {
    content: "";
    position: fixed;
    inset: 0;
    z-index: 900;
    pointer-events: none;
}

body::before {
    background: repeating-linear-gradient(0deg, rgba(var(--scan-rgb), 0.025) 0, rgba(var(--scan-rgb), 0.025) 1px, transparent 1px, transparent 3px);
}

body::after {
    background: radial-gradient(ellipse at center, transparent 32%, rgba(var(--shade-rgb), calc(var(--vignette) * 0.45)) 68%, rgba(var(--shade-rgb), var(--vignette)) 100%);
    transition: opacity 0.3s;
}

body.no-shadow::after {
    opacity: 0;
}

#field {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    display: block;
}

/* Top bar */
.hud {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: calc(56px + env(safe-area-inset-top, 0px));
    padding-top: env(safe-area-inset-top, 0px);
    display: flex;
    align-items: center;
    gap: 28px;
    padding-left: 24px;
    padding-right: 800px;
    color: var(--accent);
    font-size: 13px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    background: linear-gradient(to bottom, rgba(var(--panel-rgb), 0.97), rgba(var(--panel-rgb), 0.86));
    border-bottom: 1px solid var(--line);
    pointer-events: none;
}

.hud .title {
    font-weight: 600;
    letter-spacing: 0.3em;
    margin-right: 12px;
    white-space: nowrap;
}

.hud .target {
    font-size: 20px;
    font-weight: 600;
    color: var(--number-bright);
    text-shadow: 0 0 12px rgba(var(--accent-rgb), 0.6);
}

.hud .stat {
    font-variant-numeric: tabular-nums;
    white-space: nowrap;
}

@media (max-width: 599px) {
    .hud .title {
        display: none;
    }
}

.button-container {
    position: fixed;
    top: 11px;
    right: 24px;
    z-index: 1001;
    display: flex;
    flex-direction: row;
    gap: 12px;
}

.demo-button,
.mode-button,
.sound-button,
.share-button,
.info-button,
.new-game-button,
.range-button,
.decimal-option,
.hint-option,
.theme-button,
.stats-button,
.shadow-button,
.lock-button,
.sink-button,
.new-number-button {
    padding: 8px 14px;
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--line);
    font-family: var(--font);
    font-size: 12px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.2s, border-color 0.2s, color 0.2s;
}

.demo-button:hover,
.mode-button:hover,
.sound-button:hover,
.share-button:hover,
.info-button:hover,
.new-game-button:hover,
.range-button:hover,
.decimal-option:hover,
.hint-option:hover,
.stats-button:hover,
.shadow-button:hover,
.lock-button:hover,
.sink-button:hover,
.new-number-button:hover {
    background: rgba(var(--accent-rgb), 0.12);
    border-color: var(--accent);
}

.demo-button.active {
    color: var(--danger);
    border-color: rgba(var(--danger-rgb), 0.6);
}

.notification {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgba(var(--panel-rgb), 0.92);
    color: var(--number-bright);
    padding: 22px 44px;
    border: 1px solid var(--accent);
    font-size: 18px;
    font-weight: 300;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    z-index: 2000;
    animation: popIn 0.35s ease-out;
    box-shadow: 0 0 40px rgba(var(--accent-rgb), 0.35), inset 0 0 20px rgba(var(--accent-rgb), 0.1);
}

@keyframes popIn {
    from {
        transform: translate(-50%, -50%) scale(0.9);
        opacity: 0;
    }
    to {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
}

.sound-button.on {
    background: rgba(var(--accent-rgb), 0.18);
    border-color: var(--accent);
}

/* Menu button: only visible on small screens, where it holds all the buttons */
.menu-button {
    display: none;
}

@media (min-width: 0px) {
    .hud {
        padding-right: 80px;
    }

    .menu-button {
        position: fixed;
        top: calc(8px + env(safe-area-inset-top, 0px));
        right: calc(12px + env(safe-area-inset-right, 0px));
        z-index: 1002;
        width: 40px;
        height: 40px;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 5px;
        background: rgba(var(--panel-rgb), 0.9);
        border: 1px solid var(--line);
        cursor: pointer;
    }

    .menu-button span {
        display: block;
        width: 18px;
        height: 1px;
        background: var(--accent);
        transition: transform 0.2s, opacity 0.2s;
    }

    .menu-button[aria-expanded="true"] {
        border-color: var(--accent);
    }

    .menu-button[aria-expanded="true"] span:nth-child(1) {
        transform: translateY(6px) rotate(45deg);
    }

    .menu-button[aria-expanded="true"] span:nth-child(2) {
        opacity: 0;
    }

    .menu-button[aria-expanded="true"] span:nth-child(3) {
        transform: translateY(-6px) rotate(-45deg);
    }

    /* The buttons become a centred pop-up with a dimmed backdrop */
    .menu-backdrop.open {
        display: block;
        position: fixed;
        inset: 0;
        z-index: 1000;
        background: rgba(var(--scrim-rgb), 0.72);
        -webkit-backdrop-filter: blur(3px);
        backdrop-filter: blur(3px);
    }

    .button-container {
        display: none;
        position: fixed;
        top: calc(50% + 28px);
        left: 50%;
        right: auto;
        transform: translate(-50%, -50%);
        z-index: 1001;
        width: min(92vw, 380px);
        max-height: calc(100vh - 76px);
        overflow-y: auto;
        flex-direction: column;
        gap: 4px;
        padding: 8px 18px;
        background: rgba(var(--panel-rgb), 0.98);
        border: 1px solid var(--accent);
        box-shadow: 0 0 40px rgba(var(--accent-rgb), 0.25), inset 0 0 20px rgba(var(--accent-rgb), 0.06);
    }

    .button-container.open {
        display: flex;
        animation: menuIn 0.2s ease-out;
    }

    .button-container .menu-label {
        display: block;
    }

    .button-container .range-group {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 6px;
    }

    .button-container .hint-group {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 6px;
    }

    .button-container .hint-option {
        padding: 6px 2px;
        text-align: center;
        font-size: 11px;
        letter-spacing: 0.04em;
    }

    .button-container .decimal-group {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 6px;
    }

    .button-container .decimal-group[hidden] {
        display: none;
    }

    .button-container .decimal-option {
        padding: 6px 2px;
        text-align: center;
        font-size: 11px;
        letter-spacing: 0.04em;
    }

    .button-container .range-button {
        padding: 6px 2px;
        text-align: center;
        font-size: 11px;
        letter-spacing: 0.04em;
    }

    .button-container .mode-group {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 8px;
    }

    .button-container button {
        width: 100%;
        padding: 6px 14px;
        text-align: left;
    }

    .mode-group button {
        padding: 6px 4px;
        text-align: center;
    }
}

@keyframes menuIn {
    from { opacity: 0; transform: translate(-50%, -48%) scale(0.96); }
    to { opacity: 1; transform: translate(-50%, -50%) scale(1); }
}

/* Mode buttons: a group in the top bar on wide screens, a grid in the pop-up */
.mode-group {
    display: flex;
    gap: 6px;
}

.menu-label {
    display: none;
    color: var(--number);
    font-size: 11px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    margin-top: 2px;
}

.menu-label:first-child {
    margin-top: 0;
}

.mode-button.on {
    background: rgba(var(--accent-rgb), 0.18);
    border-color: var(--accent);
    color: var(--number-bright);
}

/* Colour choices only appear in the pop-up too */
/* Range choices live in the pop-up menu */
.range-group {
    display: none;
}

.hint-group {
    display: none;
}

.decimal-group {
    display: none;
}

.hint-option.on,
.decimal-option.on,
.range-button.on {
    background: rgba(var(--accent-rgb), 0.18);
    border-color: var(--accent);
    color: var(--number-bright);
}

.menu-backdrop {
    display: none;
}

button {
    -webkit-tap-highlight-color: transparent;
}

button:focus {
    outline: none;
}

button:focus-visible {
    outline: 1px solid var(--accent);
    outline-offset: 2px;
}

/* Switch rows: a label with a real on/off toggle */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    padding: 7px 12px;
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--line);
    font-family: var(--font);
    font-size: 12px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-align: left;
    cursor: pointer;
    white-space: nowrap;
    transition: background-color 0.2s, border-color 0.2s;
}

.toggle-row:hover {
    background: rgba(var(--accent-rgb), 0.1);
    border-color: var(--accent);
}

.toggle-switch {
    position: relative;
    flex: none;
    width: 38px;
    height: 20px;
    border-radius: 10px;
    background: rgba(var(--accent-rgb), 0.1);
    border: 1px solid var(--line);
    transition: background-color 0.2s, border-color 0.2s;
}

.toggle-switch::after {
    content: "";
    position: absolute;
    top: 2px;
    left: 2px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--knob-off);
    transition: transform 0.2s, background-color 0.2s;
}

.toggle-row.on .toggle-switch {
    background: rgba(var(--accent-rgb), 0.5);
    border-color: var(--accent);
}

.toggle-row.on .toggle-switch::after {
    transform: translateX(18px);
    background: #ffffff;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
}

/* In the pop-up the rows span the full width, like the other buttons */
@media (min-width: 0px) {
    .button-container .toggle-row {
        width: 100%;
        padding: 3px 14px;
    }
}

/* Statistics + New Number: inline in the top bar, side by side in the pop-up */
.action-row {
    display: contents;
}

@media (min-width: 0px) {
    .button-container .action-row {
        display: grid;
        grid-template-columns: 1fr 1fr 46px;
        gap: 6px;
    }

    .button-container .action-row button {
        padding-left: 6px;
        padding-right: 6px;
        text-align: center;
    }
}

/* Statistics panel */
.stats-overlay {
    position: fixed;
    inset: 0;
    z-index: 1200;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(var(--scrim-rgb), 0.78);
    -webkit-backdrop-filter: blur(3px);
    backdrop-filter: blur(3px);
}

.stats-overlay[hidden] {
    display: none;
}

.stats-panel {
    width: min(92vw, 400px);
    max-height: 88vh;
    display: flex;
    flex-direction: column;
    padding: 20px 20px 16px;
    background: rgba(var(--panel-rgb), 0.98);
    border: 1px solid var(--accent);
    box-shadow: 0 0 40px rgba(var(--accent-rgb), 0.25), inset 0 0 20px rgba(var(--accent-rgb), 0.06);
    color: var(--accent);
}

.stats-title {
    font-size: 13px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--number);
    margin-bottom: 14px;
}

.stats-body {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    overscroll-behavior: contain;
    touch-action: pan-y;
    margin: 0 -8px 14px;
    padding: 0 8px;
}

.stats-section {
    margin-bottom: 18px;
}

.stats-heading {
    margin: 0 0 8px;
    padding-bottom: 5px;
    font-size: 11px;
    font-weight: 400;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--accent);
    border-bottom: 1px solid var(--line);
}

.stats-list {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 7px 16px;
    margin: 0;
    font-variant-numeric: tabular-nums;
}

.stats-list dt {
    font-size: 11px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--number);
    align-self: center;
}

.stats-list dd {
    margin: 0;
    font-size: 17px;
    font-weight: 300;
    color: var(--number-bright);
    text-align: right;
}

.stats-actions {
    display: flex;
    gap: 10px;
}

.stats-action {
    flex: 1;
    padding: 11px 8px;
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--line);
    font-family: var(--font);
    font-size: 12px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    cursor: pointer;
}

.stats-action:hover {
    background: rgba(var(--accent-rgb), 0.12);
    border-color: var(--accent);
}

.stats-action.confirm {
    color: var(--danger);
    border-color: rgba(var(--danger-rgb), 0.7);
}

.bars-caption {
    margin: 12px 0 6px;
    font-size: 10px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--number);
}

.bars {
    display: flex;
    align-items: flex-end;
    gap: 4px;
    height: 46px;
}

.bar {
    flex: 1;
    background: rgba(var(--accent-rgb), 0.55);
    border-radius: 1px;
}

.bar:last-child {
    background: var(--accent);
}

.mode-table {
    width: 100%;
    border-collapse: collapse;
    font-variant-numeric: tabular-nums;
}

.mode-table th {
    padding: 0 0 6px;
    font-size: 10px;
    font-weight: 400;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--number);
    text-align: right;
}

.mode-table td {
    padding: 4px 0;
    font-size: 14px;
    font-weight: 300;
    color: var(--number-bright);
    text-align: right;
}

.mode-table th:first-child,
.mode-table td:first-child {
    text-align: left;
    color: var(--accent);
}

.minimap {
    display: block;
    width: 100%;
    border: 1px solid var(--line);
}

.badges {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
}

.badge {
    padding: 8px 9px;
    border: 1px solid rgba(var(--accent-rgb), 0.18);
    opacity: 0.45;
}

.badge.got {
    opacity: 1;
    border-color: var(--accent);
    background: rgba(var(--accent-rgb), 0.08);
}

.badge-name {
    font-size: 12px;
    letter-spacing: 0.06em;
    color: var(--number-bright);
}

.badge-hint {
    margin-top: 3px;
    font-size: 10px;
    line-height: 1.3;
    color: var(--number);
}

/* Toast, e.g. for a new achievement */
.toast {
    position: fixed;
    left: 50%;
    bottom: 96px;
    transform: translateX(-50%);
    max-width: 88vw;
    padding: 12px 20px;
    background: rgba(var(--panel-rgb), 0.95);
    border: 1px solid var(--accent);
    color: var(--number-bright);
    font-size: 13px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    z-index: 2100;
    pointer-events: none;
    box-shadow: 0 0 24px rgba(var(--accent-rgb), 0.3);
    animation: toastIn 0.3s ease-out;
}

@keyframes toastIn {
    from { opacity: 0; transform: translateX(-50%) translateY(10px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.new-game-button.confirm {
    color: var(--danger);
    border-color: rgba(var(--danger-rgb), 0.7);
}

/* Hot / cold hint pill */
.hint-pill {
    position: fixed;
    left: 16px;
    bottom: calc(28px + env(safe-area-inset-bottom, 0px));
    z-index: 950;
    padding: 9px 14px;
    background: rgba(var(--panel-rgb), 0.92);
    color: var(--number-bright);
    border: 1.5px solid var(--accent);
    font-size: 12px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    pointer-events: none;
    transition: border-color 0.3s;
}

.hint-pill[hidden] {
    display: none;
}

.hint-pill.in-view {
    border-color: #ff2b2b;
    color: #ff2b2b;
}

.hint-pill.in-zone {
    border-color: #ffb02b;
    color: #ffb02b;
}

/* The round "i" button in the menu */
.info-button {
    border-radius: 50%;
    font-family: Georgia, "Times New Roman", serif;
    font-style: italic;
    font-weight: 700;
    font-size: 17px;
    letter-spacing: 0;
    text-transform: none;
    padding: 0;
}

@media (min-width: 0px) {
    .button-container .action-row .info-button {
        width: 100%;
        aspect-ratio: 1;
        padding: 0;
        text-align: center;
        border-radius: 50%;
    }
}

/* About panel */
.about-overlay {
    position: fixed;
    inset: 0;
    z-index: 1300;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(var(--scrim-rgb), 0.8);
    -webkit-backdrop-filter: blur(3px);
    backdrop-filter: blur(3px);
}

.about-overlay[hidden] {
    display: none;
}

.about-panel {
    width: min(86vw, 340px);
    padding: 26px 24px 20px;
    text-align: center;
    background: rgba(var(--panel-rgb), 0.98);
    border: 1px solid var(--accent);
    box-shadow: 0 0 40px rgba(var(--accent-rgb), 0.25);
    color: var(--accent);
}

.about-icon {
    display: block;
    margin: 0 auto 12px;
    border-radius: 16px;
}

.about-title {
    font-size: 16px;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--number-bright);
}

.about-version {
    margin-top: 4px;
    font-size: 11px;
    letter-spacing: 0.18em;
    color: var(--number);
}

.about-label {
    margin-top: 20px;
    font-size: 10px;
    letter-spacing: 0.25em;
    text-transform: uppercase;
    color: var(--number);
}

.about-name {
    margin-top: 4px;
    font-size: 20px;
    font-weight: 300;
    color: var(--number-bright);
}

.about-link {
    margin-top: 10px;
    font-size: 12px;
    letter-spacing: 0.04em;
    word-break: break-all;
    user-select: text;
}

.about-note {
    margin: 18px 0 20px;
    font-size: 11px;
    line-height: 1.6;
    color: var(--number);
}

.about-panel .stats-action {
    width: 100%;
    flex: none;
}

/* Matrix: the countdown to the next flush */
.flush-bar {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    bottom: -1px;
    height: 3px;
    background: rgba(var(--accent-rgb), 0.15);
}

:root[data-theme="matrix"] .flush-bar {
    display: block;
}

.flush-bar i {
    display: block;
    height: 100%;
    width: 100%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
    transform-origin: left center;
}

.flush-bar.warn i {
    background: #ffb02b;
    box-shadow: 0 0 8px #ffb02b;
}

.flush-bar.danger i {
    background: #ff3b30;
    box-shadow: 0 0 10px #ff3b30;
}

#timeLabel.warn {
    color: #ffb02b;
}

#timeLabel.danger {
    color: #ff3b30;
}

/* Four modes in a row */
.mode-group {
    display: grid;
    grid-auto-flow: column;
    grid-auto-columns: 1fr;
}

@media (min-width: 0px) {
    .button-container .mode-group {
        grid-template-columns: none;
        grid-auto-flow: column;
        grid-auto-columns: 1fr;
        gap: 5px;
    }

    .button-container .mode-group .mode-button {
        padding: 8px 2px;
        font-size: 11px;
        letter-spacing: 0.06em;
    }
}