/* 在线双耳节拍 */
.bb-range {
    width: 100%;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    border-radius: 999px;
    background: var(--c-surface-soft, #eef1f5);
    outline: none;
}
.bb-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #0096dc;
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 1px 4px rgba(0, 0, 0, .2);
}
.bb-range::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #0096dc;
    cursor: pointer;
    border: 2px solid #fff;
}

.bb-display {
    text-align: center;
    padding: 18px 12px;
    margin-bottom: 14px;
    border-radius: 12px;
    background: var(--c-surface-soft, #f6f8fa);
}

.bb-freq {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
    flex-wrap: wrap;
}
.bb-ear, .bb-brain {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
}
.bb-ear .k, .bb-brain .k {
    font-size: 11.5px;
    color: var(--c-text-muted, #9aa5b1);
}
.bb-ear b {
    font-size: 22px;
    font-weight: 800;
    color: var(--c-text, #1f2933);
    font-variant-numeric: tabular-nums;
}
.bb-brain b {
    font-size: 34px;
    font-weight: 800;
    color: #0096dc;
    font-variant-numeric: tabular-nums;
}
.bb-ear small, .bb-brain small {
    font-size: 11px;
    color: var(--c-text-muted, #9aa5b1);
}

/* 播放指示动画 */
.bb-wave {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
    height: 30px;
    margin-top: 12px;
}
.bb-wave span {
    width: 4px;
    height: 8px;
    border-radius: 2px;
    background: var(--c-border, #cfd6de);
    transition: height .3s, background .3s;
}
.bb-wave.is-on span {
    background: #0096dc;
    animation: bb-breathe 2.4s ease-in-out infinite;
}
.bb-wave.is-on span:nth-child(2) { animation-delay: .2s; }
.bb-wave.is-on span:nth-child(3) { animation-delay: .4s; }
.bb-wave.is-on span:nth-child(4) { animation-delay: .6s; }
.bb-wave.is-on span:nth-child(5) { animation-delay: .8s; }

@keyframes bb-breathe {
    0%, 100% { height: 8px; }
    50% { height: 26px; }
}

.bb-sub {
    margin-top: 8px;
    font-size: 12.5px;
    color: var(--c-text-sub, #5b6572);
}

.bb-note {
    margin-top: 12px;
    padding: 10px 12px;
    border-radius: 10px;
    font-size: 13px;
    line-height: 1.7;
}
.bb-note.is-info { background: rgba(0, 150, 220, .1); color: #0a7fc0; }
.bb-note.is-err { background: rgba(220, 38, 38, .1); color: #b91c1c; }

[data-theme="dark"] .bb-note.is-info { color: #58bdf0; }
[data-theme="dark"] .bb-note.is-err { color: #f87171; }