/* 基礎設定與深夜模式配色 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #121212; /* 深夜背景 */
    color: #e0e0e0; /* 淺色文字 */
    text-align: center;
}
.container {
    padding: 20px;
    max-width: 420px; /* 模擬手機寬度 */
    margin: 0 auto;
}
h1 {
    color: #00bcd4; /* 醒目藍色 */
    font-size: 1.8em;
    padding-bottom: 10px;
    border-bottom: 1px solid #333;
}
/* 速度顯示區 */
#speed-section {
    background-color: #1e1e1e;
    padding: 30px 15px;
    margin-bottom: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
}
.speed-display {
    font-size: 5em;
    font-weight: 700;
    color: #4caf50; /* 綠色，表示運行正常 */
    display: block;
    line-height: 1.1;
}
.speed-display.stopped {
    color: #ff9800; /* 橘色，表示已靜止/低速 */
}
#status-light {
    font-size: 2em;
    margin-bottom: 10px;
    height: 30px; 
}
/* 詳細資訊區 (小字) */
#details {
    text-align: left;
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px dashed #333;
    font-size: 0.9em;
}
.detail-item { margin-bottom: 8px; }
.detail-label {
    color: #9e9e9e; 
    width: 120px;
    display: inline-block;
}
.detail-value {
    color: #e0e0e0;
    font-weight: bold;
}

/* 語言和單位切換區塊 */
#settings-group {
    margin-top: 10px;
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.selector-group {
    background-color: #2a2a2a;
    padding: 10px;
    border-radius: 8px;
    text-align: center;
    font-size: 0.95em;
}
.selector-group h4 {
    margin: 0 0 8px 0;
    color: #bdbdbd;
}
.radio-item {
    display: inline-flex;
    align-items: center;
    margin: 0 6px;
    cursor: pointer;
}
.radio-item input[type="radio"] {
    margin-right: 4px;
    accent-color: #00bcd4;
}

/* 按鈕區 */
.button-group {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}
button {
    flex-grow: 1;
    padding: 15px 10px;
    font-size: 1.1em;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    transition: background-color 0.3s;
}
#startBtn { background-color: #4caf50; color: white; }
#stopBtn { background-color: #f44336; color: white; }
button:disabled { opacity: 0.5; cursor: not-allowed; }

/* 廣告輪播區塊 */
#ad-carousel {
    position: relative;
    width: 100%;
    height: 120px; /* 廣告高度 */
    background-color: #333;
    margin-top: 20px;
    border-radius: 12px;
    overflow: hidden; 
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    cursor: pointer;
}
#ad-carousel img {
    width: 100%;
    height: 100%;
    object-fit: cover; 
    display: none; 
    position: absolute;
    top: 0;
    left: 0;
}
#ad-carousel img.active {
    display: block; 
}
.ad-dots {
    position: absolute;
    bottom: 8px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 6px;
}
.ad-dot {
    width: 8px;
    height: 8px;
    background-color: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s;
}
.ad-dot.active {
    background-color: #00bcd4;
    width: 18px; /* 活躍點變長 */
    border-radius: 4px;
}