:root {
    /* Color padding: ; */
    --color-bg: #0c0c14;
    --color-surface: #111118;
    --color-text: #f4f4f5;
    --color-accent: #7c86ff;

    /* Typography */
    --font-family: "Roboto", sans-serif;

    --font-size-heading: 28px;
    --font-size-subheading: 20px;
    --font-size-body: 16px;
    --font-size-label: 14px;
    --font-size-caption: 12px;

    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-bold: 700;

    /* Border */
    --border-width: 1px;
    --border-color: rgba(255, 255, 255, 0.12);
    --border: var(--border-width) solid var(--border-color);

    /* Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
}

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

body {
    color: var(--color-text);
    font-family: var(--font-family);
    font-size: var(--font-size-body);
    font-weight: var(--font-weight-regular);
}

body > main {
    background-color: var(--color-bg);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 24px;
}

/* Custom Components */
/* # Card # */
.card {
    background-color: var(--color-surface);
    border: var(--border);
    border-radius: var(--radius-md);
    padding: 20px;
}

.card--compact {
    padding: 12px;
}

.card--elevated {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* # Button # */
.btn {
    background-color: transparent;
    color: var(--color-text);
    border: var(--border);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    font-family: inherit;
    font-size: var(--font-size-label);
    cursor: pointer;
    transition:
        background-color 150ms ease-out,
        border-color 150ms ease-out;
}

.btn:hover {
    background-color: rgba(255, 255, 255, 0.04);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn--primary {
    background-color: var(--color-accent);
    border-color: var(--color-accent);
}

.btn--primary:hover {
    background-color: #5b6ad4;
    border-color: #5b6ad4;
}

.btn--toggle {
    flex: 1;
    padding: 6px 10px;
    font-size: var(--font-size-caption);
}

.btn--active {
    background-color: rgba(124, 134, 255, 0.15);
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.btn--icon {
    width: 32px;
    height: 32px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-subheading);
    line-height: 1;
}

/* App Layout */

.container {
    width: 100%;
    max-width: 1200px;
    display: grid;
    align-items: stretch;
    grid-template-columns: 1fr 360px;
    gap: 24px;
}

#playground {
    position: relative;
    width: 100%;
    height: 100%;
    min-height: 500px;
}

.sidebar {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.seesaw-box {
    position: relative;
}

/* Sidebar */

.stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat__label {
    font-size: var(--font-size-caption);
    color: var(--color-text);
    opacity: 0.6;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat__value {
    font-size: var(--font-size-subheading);
    font-weight: var(--font-weight-medium);
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.controls__title {
    font-size: var(--font-size-caption);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.6;
    font-weight: var(--font-weight-medium);
}

.controls__group {
    display: flex;
    gap: 8px;
}

.controls__mode {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.controls__label {
    font-size: var(--font-size-caption);
    opacity: 0.6;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.controls__toggle {
    display: flex;
    gap: 4px;
    margin-left: auto;
}

.controls__stepper {
    display: flex;
    align-items: center;
    gap: 8px;
}

.controls__stepper output {
    text-align: center;
    font-variant-numeric: tabular-nums;
    font-weight: var(--font-weight-medium);
}

.controls__row {
    display: flex;
    align-items: center;
    gap: 8px;
}

.log {
    display: flex;
    flex-direction: column;
    gap: 12px;
    height: 240px;
}

.log__title {
    font-size: var(--font-size-caption);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.6;
    font-weight: var(--font-weight-medium);
}

.log__list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
    overflow-y: auto;
    padding-right: 4px;
}

.log__item {
    font-size: var(--font-size-caption);
    padding: 6px 8px;
    background-color: rgba(255, 255, 255, 0.02);
    border-left: 2px solid var(--color-accent);
    border-radius: var(--radius-sm);
    font-variant-numeric: tabular-nums;
    animation: logAppear 300ms ease-out;
}

.log__item--left {
    border-left-color: #60a5fa;
}

.log__item--right {
    border-left-color: #f59e0b;
}

.log__empty {
    font-size: var(--font-size-caption);
    opacity: 0.4;
    font-style: italic;
    text-align: center;
    padding: 16px 8px;
}

.log__list::-webkit-scrollbar {
    width: 4px;
}

.log__list::-webkit-scrollbar-track {
    background: transparent;
}

.log__list::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 2px;
}

/* Playground Setup */

#hover-preview {
    position: absolute;
    border: 2px dashed var(--color-text);
    border-radius: var(--radius-sm);
    opacity: 0.4;
    pointer-events: none;
    transition: opacity 150ms ease-out;
    z-index: 5;
}

#distance-indicator {
    position: absolute;
    pointer-events: none;
    height: 0;
    border-top: 1px dashed var(--color-text);
    opacity: 0.5;
    z-index: 4;
    transition: opacity 150ms ease-out;
}

#distance-value {
    position: absolute;
    top: 0px;
    left: 50%;
    transform: translateX(-50%);
    font-size: var(--font-size-caption);
    color: var(--color-text);
    font-variant-numeric: tabular-nums;
    white-space: nowrap;
    background: rgba(0, 0, 0, 0.7);
    padding: 2px 6px;
    border-radius: var(--radius-sm);
}

#next-weight {
    position: absolute;
    top: 0;
    left: 0;
    margin: 30px 20px;
    border-radius: var(--radius-sm);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.next-weight__label {
    position: absolute;
    top: -20px;
    left: 0;
    font-size: var(--font-size-label);
    font-weight: var(--font-weight-bold);
    opacity: 0.6;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

#next-weight .box {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-sm);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: var(--font-size-body);
    color: var(--color-text);
}

#plank {
    position: absolute;
    left: 50%;
    top: 65%;
    transform: translateX(-50%) rotate(0);
    width: 400px;
    height: 12px;
    background-color: var(--color-accent);
    border-radius: 4px;
    z-index: 9;
    transition: transform 400ms ease-out;
}

#pivot {
    position: absolute;
    left: 50%;
    top: 64%;
    transform: translateX(-50%);
    width: 24px;
    height: 24px;
    background-color: var(--color-text);
    border-radius: 50%;
    margin-top: 8px;
    z-index: 9;
}

#ground-shadow {
    position: absolute;
    left: 50%;
    top: 85%;
    transform: translateX(-50%);
    width: 400px;
    height: 12px;
    background-color: rgba(0, 0, 0, 0.1);
    border-radius: 4px;
    z-index: 11;
    transition: width 400ms ease-out;
}

#pause-banner {
    position: absolute;
    pointer-events: none;
    width: 100%;
    height: 100%;
    border-radius: 4px;
    background-color: rgba(0, 0, 0, 0);
    color: transparent;
    font-size: var(--font-size-caption);
    font-weight: var(--font-weight-bold);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 12;
    transition:
        background-color 400ms ease-out,
        color 400ms ease-out;
}

#pause-banner.active {
    background-color: rgba(0, 0, 0, 0.8);
    color: var(--color-text);
}

.weight {
    position: absolute;
    width: 40px;
    height: 40px;
    background-color: var(--color-accent);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-caption);
    font-weight: var(--font-weight-bold);
    color: var(--color-text);
    user-select: none;
    pointer-events: none;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

/* Animations */

@keyframes logAppear {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}