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

:root {
    --bg-page: #0a0a0a;
    --bg-stage: #111111;
    --bg-button: rgba(255, 255, 255, 0.08);
    --bg-button-hover: rgba(255, 255, 255, 0.15);
    --border-button: rgba(255, 255, 255, 0.2);
    --accent: #00d4ff;
    --danger: #ff4757;
    --text: #ffffff;
    --button-size: 52px;
    --stage-radius: 24px;
}

html, body {
    height: 100%;
    background: var(--bg-page);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    overflow: hidden;
}

.container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    height: 100%;
    padding: 32px;
}

/* Video Stage */
.stage {
    position: relative;
    width: 100%;
    max-width: 900px;
    aspect-ratio: 16 / 9;
    background: var(--bg-stage);
    border-radius: var(--stage-radius);
    overflow: hidden;
    box-shadow:
        0 4px 24px rgba(0, 0, 0, 0.5),
        0 0 0 1px rgba(255, 255, 255, 0.05);
}

.stage video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: none;
}

.stage video.visible {
    display: block;
}

.stage-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-stage);
    pointer-events: none;
    opacity: 1;
    transition: opacity 0.3s ease;
}

.stage-overlay.hidden {
    opacity: 0;
}

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

.btn {
    width: var(--button-size);
    height: var(--button-size);
    border-radius: 50%;
    border: 2px solid var(--border-button);
    background: var(--bg-button);
    color: var(--text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.btn svg {
    width: 24px;
    height: 24px;
}

.btn:hover {
    background: var(--bg-button-hover);
    border-color: rgba(255, 255, 255, 0.4);
    transform: scale(1.05);
}

.btn:active {
    transform: scale(0.95);
}

.btn.active {
    border-color: var(--accent);
    box-shadow:
        0 0 12px rgba(0, 212, 255, 0.4),
        inset 0 0 8px rgba(0, 212, 255, 0.1);
}

.btn--danger.active {
    border-color: var(--danger);
    box-shadow:
        0 0 12px rgba(255, 71, 87, 0.4),
        inset 0 0 8px rgba(255, 71, 87, 0.1);
}

/* Focus states for accessibility */
.btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.3);
}

.btn:focus:not(:focus-visible) {
    box-shadow: none;
}

.btn:focus-visible {
    box-shadow: 0 0 0 3px rgba(0, 212, 255, 0.5);
}