@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=Manrope:wght@400;500;600;700;800&family=IBM+Plex+Mono:wght@400;500;600&display=swap');

:root {
    --font-ui: 'Manrope', sans-serif;
    --font-display: 'DM Serif Display', serif;
    --font-mono: 'IBM Plex Mono', monospace;

    --bg-color: #111110;
    --bg-pattern: #1A1A18;
    --panel-bg: rgba(30, 30, 28, 0.88);
    --panel-border: rgba(255, 255, 255, 0.08);
    --text-main: #EDEBE8;
    --text-muted: #9C9890;

    --brand-primary: #E8734A;
    --brand-secondary: #F4845F;
    --brand-accent: #2DD4BF;
    --danger: #ff5d5d;
    --nav-bg: rgba(17, 17, 16, 0.85);
    --nav-border: rgba(255, 255, 255, 0.05);

    --btn-create: #3cc282;
    --btn-create-hover: #32b074;
    --btn-create-text: #1a1a1a;
    --btn-danger: #e87575;
    --btn-danger-hover: #dc6363;
    --btn-danger-text: #1a1a1a;
    --btn-import: #f0a35c;
    --btn-import-hover: #e5944a;
    --btn-import-text: #1a1a1a;
    --btn-reset: #D8D3CB;
    --btn-reset-hover: #C8C3BB;
    --btn-reset-text: #1B1B1B;
}

[data-theme="light"] {
    --bg-color: #F8F6F1;
    --bg-pattern: #EDE9E0;
    --panel-bg: rgba(248, 246, 241, 0.9);
    --panel-border: rgba(194, 65, 12, 0.2);
    --text-main: #1B1B1B;
    --text-muted: #6B6560;

    --brand-primary: #C2410C;
    --brand-secondary: #EA580C;
    --brand-accent: #0D9488;
    --danger: #b91c1c;
    --nav-bg: rgba(248, 246, 241, 0.88);
    --nav-border: rgba(0, 0, 0, 0.06);

    --btn-create: #2eac71;
    --btn-create-hover: #259a63;
    --btn-create-text: #ffffff;
    --btn-danger: #dc5f5f;
    --btn-danger-hover: #c94d4d;
    --btn-danger-text: #ffffff;
    --btn-import: #e59347;
    --btn-import-hover: #d5823a;
    --btn-import-text: #1a1a1a;
    --btn-reset: #E8E4DD;
    --btn-reset-hover: #D8D3CB;
    --btn-reset-text: #1B1B1B;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100svh;
    font-family: var(--font-ui);
    color: var(--text-main);
    background-color: var(--bg-color);
    background-image: radial-gradient(var(--bg-pattern) 1px, transparent 1px);
    background-size: 30px 30px;
    display: flex;
    flex-direction: column;
    padding-bottom: env(safe-area-inset-bottom);
    -webkit-user-select: none;
    user-select: none;
}

.app {
    width: min(1100px, calc(100% - 24px));
    display: grid;
    gap: 12px;
    margin: 12px auto;
    flex: 1 0 auto;
}

.instruction-message {
    background: rgba(13, 148, 136, 0.1);
    color: var(--text-main);
    padding: 10px 15px;
    border-radius: 12px;
    margin: 0 auto;
    width: 100%;
    max-width: 1160px;
    text-align: center;
    border: 1px solid rgba(13, 148, 136, 0.25);
}

.instruction-message p {
    margin: 0;
}

.panel {
    border: 1px solid var(--panel-border);
    background: var(--panel-bg);
    border-radius: 16px;
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.topbar {
    background: var(--nav-bg);
    color: var(--text-main);
    border-bottom: 1px solid var(--nav-border);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.topbar .bar {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 62px;
    padding: 12px 16px;
}

.topbar .brand {
    position: absolute;
    left: 12px;
    display: inline-flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-main);
}

.topbar .brand img {
    height: 34px;
    width: auto;
    display: block;
}

.topbar .title {
    margin: 0;
    font-family: var(--font-display);
    font-size: 1.45rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    color: var(--brand-primary);
}

.topbar .title.gradient-text {
    background: linear-gradient(135deg, var(--brand-primary), var(--brand-accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

#controlsToggle {
    position: absolute;
    bottom: calc(12px + env(safe-area-inset-bottom, 0px));
    left: 12px;
    z-index: 18;
    width: auto;
    min-height: 38px;
    padding: 8px 12px;
    border-radius: 10px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(17, 17, 16, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
    color: var(--text-main);
    font-size: 0.85rem;
    font-weight: 600;
}

.controls-main {
    display: grid;
    gap: 8px;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    align-items: end;
}

.controls-panel {
    position: absolute;
    bottom: calc(12px + env(safe-area-inset-bottom, 0px));
    left: 12px;
    z-index: 19;
    display: none;
    width: min(470px, calc(100% - 24px));
    max-height: calc(100% - 24px - env(safe-area-inset-bottom, 0px));
    overflow-y: auto;
    padding: 12px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 14px;
    background: rgba(17, 17, 16, 0.82);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
}

[data-theme="light"] .controls-panel {
    background: rgba(248, 246, 241, 0.9);
}

.controls-panel.open {
    display: block;
}

#controlsClose {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 30px;
    min-height: 30px;
    border-radius: 8px;
    padding: 0;
    font-size: 0.85rem;
    border-color: transparent;
    background: transparent;
    color: var(--text-muted);
    box-shadow: none;
}

#controlsClose:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: transparent;
    color: var(--text-main);
}

.cp-section {
    display: grid;
    gap: 8px;
}

.cp-label {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-muted);
    padding-right: 30px;
}

.cp-divider {
    height: 1px;
    margin: 10px 0;
    background: rgba(255, 255, 255, 0.06);
}

.controls-panel .controls-main {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.physics-controls {
    width: 100%;
    border: 1px solid var(--panel-border);
    border-radius: 12px;
    background: rgba(17, 17, 16, 0.5);
    margin: 0;
    padding: 0;
    overflow: hidden;
}

[data-theme="light"] .physics-controls {
    background: rgba(255, 255, 255, 0.7);
}

.physics-controls>summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    border: none;
    background: transparent;
    color: var(--text-main);
    font: 600 0.9rem/1.2 var(--font-ui);
    padding: 10px 12px;
    min-height: 48px;
    cursor: pointer;
    list-style: none;
    user-select: none;
}

.physics-summary-copy {
    font-weight: 700;
}

.summary-caret {
    font-size: 0.8rem;
    color: var(--text-muted);
    transition: transform 0.18s ease;
}

.physics-controls[open] .summary-caret {
    transform: rotate(180deg);
}

.physics-controls>summary::-webkit-details-marker {
    display: none;
}

.physics-controls>summary:hover {
    background: rgba(255, 255, 255, 0.05);
}

[data-theme="light"] .physics-controls>summary:hover {
    background: rgba(148, 163, 184, 0.14);
}

.physics-controls-inner {
    display: grid;
    gap: 12px;
    padding: 12px;
    border-top: 1px solid color-mix(in srgb, var(--panel-border) 75%, transparent);
}

.physics-toggle-row {
    display: flex;
    gap: 16px;
    padding-bottom: 4px;
}

.toggle-block {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 0.74rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    cursor: pointer;
}

.switch {
    position: relative;
    display: inline-block;
    width: 42px;
    height: 22px;
    flex-shrink: 0;
    cursor: pointer;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.switch-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background-color: #3A3A36;
    transition: background-color 0.25s ease;
    border-radius: 22px;
}

[data-theme="light"] .switch-slider {
    background-color: #D8D3CB;
}

.switch-slider::before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 3px;
    bottom: 3px;
    background-color: #fff;
    transition: transform 0.25s ease;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.switch input:checked + .switch-slider {
    background-color: var(--brand-accent);
}

[data-theme="dark"] .switch input:checked + .switch-slider {
    background-color: #2DD4BF;
}

.switch input:checked + .switch-slider::before {
    transform: translateX(20px);
}

.physics-slider-grid {
    display: grid;
    gap: 10px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: end;
}

.ball-controls {
    margin-top: 12px;
    border: 1px solid var(--panel-border);
    border-radius: 12px;
    background: rgba(17, 17, 16, 0.5);
    overflow: hidden;
}

[data-theme="light"] .ball-controls {
    background: rgba(255, 255, 255, 0.7);
}

.ball-controls-summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 12px;
    cursor: pointer;
    list-style: none;
    user-select: none;
}

.ball-controls-summary::-webkit-details-marker {
    display: none;
}

.ball-controls-summary:hover {
    background: rgba(255, 255, 255, 0.05);
}

[data-theme="light"] .ball-controls-summary:hover {
    background: rgba(148, 163, 184, 0.14);
}

.ball-controls-head {
    display: flex;
    align-items: center;
    gap: 8px;
}

.ball-controls-head .cp-label {
    padding-right: 0;
}

.ball-controls-body {
    display: grid;
    gap: 10px;
    padding: 0 12px 12px;
    border-top: 1px solid color-mix(in srgb, var(--panel-border) 75%, transparent);
}

.ball-controls[open] .summary-caret {
    transform: rotate(180deg);
}

.ball-controls .control-help {
    margin: 0;
}

.ball-controls-list {
    display: grid;
    gap: 10px;
}

.ball-control-card {
    display: grid;
    gap: 10px;
    padding: 10px;
    border-radius: 10px;
    border: 1px solid color-mix(in srgb, var(--panel-border) 90%, transparent);
    background: rgba(26, 26, 24, 0.78);
}

[data-theme="light"] .ball-control-card {
    background: rgba(255, 255, 255, 0.88);
}

.ball-control-header {
    display: flex;
    align-items: center;
    gap: 8px;
}

.ball-control-grid {
    display: grid;
    gap: 10px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: end;
}

.ball-color-dot {
    width: 10px;
    height: 10px;
    border-radius: 999px;
    box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.45);
}

.ball-control-title {
    color: var(--text-main);
    font-size: 0.84rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}

button {
    border: 1px solid var(--panel-border);
    background: rgba(30, 30, 28, 0.8);
    color: var(--text-main);
    font: 500 0.92rem/1 var(--font-ui);
    border-radius: 10px;
    padding: 10px 12px;
    min-height: 48px;
    width: 100%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
}

[data-theme="light"] button {
    background: rgba(255, 255, 255, 0.86);
}

button:hover:not(:disabled) {
    border-color: var(--brand-primary);
    transform: translateY(-1px);
}

button:disabled {
    opacity: 0.46;
    cursor: not-allowed;
}

#startBtn,
#addBtn,
#resetBtn {
    border: 1px solid transparent;
    font-weight: 700;
}

#startBtn {
    background: var(--btn-create);
    color: var(--btn-create-text);
}

#startBtn:hover:not(:disabled) {
    background: var(--btn-create-hover);
    border-color: transparent;
}

#startBtn.is-stop {
    background: var(--btn-danger);
    color: var(--btn-danger-text);
}

#startBtn.is-stop:hover:not(:disabled) {
    background: var(--btn-danger-hover);
    border-color: transparent;
}

#startBtn:disabled {
    opacity: 0.82;
    color: var(--btn-create-text);
}

#startBtn.is-stop:disabled {
    color: var(--btn-danger-text);
}

#addBtn {
    background: var(--btn-import);
    color: var(--btn-import-text);
}

#addBtn:hover:not(:disabled) {
    background: var(--btn-import-hover);
    border-color: transparent;
}

#resetBtn {
    background: var(--btn-reset);
    color: var(--btn-reset-text);
}

#resetBtn:hover:not(:disabled) {
    background: var(--btn-reset-hover);
    border-color: transparent;
}

.control-block {
    display: grid;
    gap: 6px;
    min-height: 48px;
    color: var(--text-muted);
    font-size: 0.74rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    align-content: start;
}

.control-label-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.control-label {
    line-height: 1.1;
}

.control-block select,
.control-block input[type="range"] {
    border: 1px solid var(--panel-border);
    border-radius: 10px;
    background: rgba(26, 26, 24, 0.72);
    color: var(--text-main);
    min-height: 40px;
    font-family: var(--font-ui);
    font-size: 0.9rem;
    padding: 6px 10px;
    width: 100%;
}

[data-theme="light"] .control-block select,
[data-theme="light"] .control-block input[type="range"] {
    background: rgba(255, 255, 255, 0.9);
}

.control-block input[type="range"] {
    padding: 0 4px;
    accent-color: var(--brand-primary);
}

.value-badge {
    color: var(--brand-accent);
    font-weight: 700;
    margin-left: 0;
    text-transform: none;
    letter-spacing: 0;
    font-size: 0.82rem;
}

.stage {
    position: relative;
    aspect-ratio: 16 / 10;
    overflow: hidden;
    isolation: isolate;
}

.stage::after {
    content: '';
    position: absolute;
    inset: 0;
    z-index: 3;
    pointer-events: none;
    opacity: 0;
    border-radius: inherit;
    transition: opacity 0.2s ease;
    box-shadow:
        inset 0 0 0 2px rgba(232, 115, 74, 0.7),
        inset 0 0 30px rgba(45, 212, 191, 0.25),
        0 0 22px rgba(194, 65, 12, 0.35);
}

.stage[data-boundary-mode="walls"]::after {
    opacity: 1;
}

[data-theme="light"] .stage::after {
    box-shadow:
        inset 0 0 0 2px rgba(194, 65, 12, 0.6),
        inset 0 0 22px rgba(194, 65, 12, 0.15),
        0 0 18px rgba(194, 65, 12, 0.2);
}

#fullscreenBtn {
    position: absolute;
    top: 12px;
    right: 12px;
    z-index: 18;
    width: 38px;
    min-height: 34px;
    padding: 0;
    border-radius: 10px;
    border-color: rgba(255, 255, 255, 0.1);
    background: rgba(17, 17, 16, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
    font-size: 1.05rem;
    line-height: 1;
}

#fullscreenBtn:hover {
    background: rgba(30, 30, 28, 0.88);
}

.stage:fullscreen,
.stage:-webkit-full-screen,
.stage.pseudo-fullscreen {
    width: 100vw;
    height: 100vh;
    max-width: none;
    aspect-ratio: auto;
    border: none;
    border-radius: 0;
}

.stage.pseudo-fullscreen {
    position: fixed;
    inset: 0;
    height: 100svh;
    height: 100dvh;
    z-index: 1200;
}

.media-layer {
    position: absolute;
    inset: 0;
    z-index: 1;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transform: scaleX(-1);
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

#camera {
    z-index: 0;
}

#renderCanvas {
    pointer-events: none;
    z-index: 1;
}

#tipCanvas {
    pointer-events: none;
    z-index: 2;
}

html.ball-fullscreen-lock,
body.ball-fullscreen-lock {
    overflow: hidden;
}

.hud {
    display: grid;
    gap: 6px;
    width: 100%;
    transition: opacity 0.2s;
    cursor: pointer;
}

.hud.hidden {
    opacity: 0;
    pointer-events: none;
}

.pill {
    border: 1px solid var(--panel-border);
    background: rgba(30, 30, 28, 0.82);
    color: var(--text-main);
    border-radius: 10px;
    padding: 8px 10px;
    font-size: 0.86rem;
    line-height: 1.2;
}

[data-theme="light"] .pill {
    background: rgba(255, 255, 255, 0.76);
}

.mono {
    font-family: var(--font-mono);
    letter-spacing: 0.01em;
}

.ios-touch-device #statusMetrics {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    line-height: 1.1;
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

.status-error {
    border-color: color-mix(in srgb, var(--danger) 66%, transparent);
    color: var(--danger);
}

.control-help {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.76rem;
    line-height: 1.2;
}

footer {
    position: static;
    font-size: 14px;
    text-align: center;
    padding: 8px;
    background: transparent;
    color: var(--text-muted);
    margin: 4px 0;
    width: 100%;
}

footer a {
    color: var(--brand-primary);
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 640px) {
    .app {
        width: min(1100px, calc(100% - 14px));
        margin: 10px auto;
        gap: 10px;
    }

    .topbar .bar {
        min-height: 56px;
        padding: 10px 10px;
    }

    .topbar .brand {
        left: 8px;
    }

    .topbar .brand img {
        height: 28px;
    }

    .topbar .title {
        font-size: 1.18rem;
    }

    .controls-panel .controls-main {
        grid-template-columns: 1fr;
    }

    .stage {
        border-radius: 14px;
    }
}

@media (min-width: 900px) {
    .topbar .bar {
        min-height: 68px;
        padding: 14px 20px;
    }

    .topbar .brand img {
        height: 36px;
    }

    .topbar .title {
        font-size: 1.58rem;
    }
}

.selection-overlay {
    position: absolute;
    inset: 0;
    background: rgba(2, 6, 23, 0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 20;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    gap: 16px;
}

[data-theme="light"] .selection-overlay {
    background: rgba(248, 246, 241, 0.6);
}

.selection-overlay-title {
    margin: 0;
    font-size: 1.2rem;
    font-weight: 600;
    text-shadow: 0 2px 8px rgba(0,0,0,0.5);
}

[data-theme="light"] .selection-overlay-title {
    text-shadow: 0 2px 8px rgba(255,255,255,0.5);
}

.selection-overlay-actions {
    display: flex;
    gap: 12px;
}

.selection-overlay-actions button {
    width: auto;
    padding: 10px 24px;
    min-height: 44px;
}

button.btn-danger {
    background: rgba(251, 113, 133, 0.2);
    border-color: var(--danger);
    color: #fff;
}

[data-theme="light"] button.btn-danger {
    background: rgba(220, 38, 38, 0.1);
    color: var(--danger);
}