/* --- timeline controls --- */

.timeline-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    max-width: 1100px;
    flex-shrink: 0;
    transition: transform 0.15s ease;
}

.timeline-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 6px;
    border: 1px solid var(--panel-border);
    background: var(--bg);
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.timeline-btn svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    fill: none;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.timeline-btn:hover,
.timeline-btn:focus-visible {
    border-color: var(--teal);
    color: var(--teal);
    outline: none;
}

.timeline-btn:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    border-color: var(--panel-border);
    color: var(--text-dim);
}

#play-pause-btn.timeline-btn {
    width: 56px;
    height: 56px;
    background: var(--teal);
    border-color: var(--teal);
    color: var(--bg);
}

#play-pause-btn.timeline-btn:hover {
    background: transparent;
    color: var(--teal);
}

#play-pause-btn .icon-pause {
    display: none;
}

#play-pause-btn.is-playing .icon-play {
    display: none;
}

#play-pause-btn.is-playing .icon-pause {
    display: block;
}