/* ==========================================================================
   Feature: Listening Mode Styles - 听力模式样式
   --------------------------------------------------------------------------
   职责:
   - 定义所有与“听力磨耳朵”模态框相关的专属样式。
   - 依赖于 modals.css 中定义的通用模态框样式。
   ========================================================================== */

/* --- 听力模式: 头部 --- */
.listening-header {
    width: 100%;
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}
.listening-mode-title {
    font-size: 1.2rem;
    color: var(--text-highlight);
}
.listening-toggle-wrapper {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9rem;
    color: var(--text-sub);
}

/* --- 听力模式: 音源切换开关 --- */
.toggle-switch {
    position: relative;
    width: 44px;
    height: 24px;
}
.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: .4s;
    border-radius: 24px;
}
.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}
input:checked + .slider {
    background-color: var(--theme-color);
}
input:checked + .slider:before {
    transform: translateX(20px);
}

/* --- 听力模式: 视觉播放区 --- */
.listening-visual {
    width: 120px;
    height: 120px;
    background: var(--bg-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    position: relative;
    cursor: pointer;
    border: 4px solid var(--border-color);
    transition: border-color 0.3s;
}
.listening-visual:hover {
    border-color: var(--theme-color);
}

/* --- 听力模式: 音波动画 --- */
.audio-waves {
    display: flex;
    align-items: center;
    gap: 4px;
    height: 40px;
}
.audio-waves span {
    display: block;
    width: 4px;
    height: 100%;
    background: var(--theme-color);
    border-radius: 2px;
    animation: wave 1s infinite ease-in-out;
    opacity: 0.3;
    transform: scaleY(0.2);
}
.audio-waves.is-playing span {
    opacity: 1;
    animation-play-state: running;
}
.audio-waves:not(.is-playing) span {
    animation-play-state: paused;
}
.audio-waves span:nth-child(1) { animation-delay: 0.0s; }
.audio-waves span:nth-child(2) { animation-delay: 0.1s; }
.audio-waves span:nth-child(3) { animation-delay: 0.2s; }
.audio-waves span:nth-child(4) { animation-delay: 0.3s; }
.audio-waves span:nth-child(5) { animation-delay: 0.4s; }

@keyframes wave {
    0%, 100% { transform: scaleY(0.2); }
    50% { transform: scaleY(1); }
}

/* --- 听力模式: 重播按钮 --- */
.listening-replay-btn {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--theme-color);
    opacity: 0;
    transition: opacity 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.listening-replay-btn svg {
    width: 40px;
    height: 40px;
}
.listening-visual:hover .listening-replay-btn {
    opacity: 0.2;
}

/* --- 听力模式: 答案区域 --- */
.listening-answer-area {
    min-height: 120px;
    width: 100%;
    background: var(--bg-secondary-color);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    border: 1px dashed var(--border-color);
}
.listening-hidden-placeholder {
    color: var(--text-sub);
    font-size: 0.9rem;
    font-style: italic;
}
.listening-revealed-content {
    animation: fadeInUp 0.3s forwards;
    text-align: left;
}
.listening-word {
    font-size: 1.6rem;
    color: var(--theme-color);
    margin-bottom: 0.2rem;
    text-align: center;
}
.listening-meaning {
    color: var(--text-sub);
    font-size: 0.9rem;
    margin-bottom: 0.8rem;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}
.listening-sentence-en {
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 0.4rem;
    font-size: 1rem;
    line-height: 1.4;
}
.listening-sentence-cn {
    font-size: 0.85rem;
    color: var(--text-sub);
}

/* --- 听力模式: 控制按钮容器 --- */
.listening-controls {
    display: flex;
    gap: 1rem;
    width: 100%;
}