:root {
    --bg-color: #000;
    --text-color: #fff;
    --select-bg: rgba(255, 255, 255, 0.1);
    --transition-duration: 0.3s;
}

.dark-theme {
    --bg-color: #000;
    --text-color: #fff;
    --select-bg: rgba(255, 255, 255, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    overflow: hidden;
    transition: background-color var(--transition-duration),
                color var(--transition-duration);
}

canvas {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1;
    transition: opacity var(--transition-duration);
}

.container {
    position: relative;
    z-index: 2;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    padding: 1rem;
}

.settings {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 1rem;
}

.icon-button {
    background: var(--select-bg);
    border: none;
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    backdrop-filter: blur(10px);
    transition: background-color var(--transition-duration);
}

.icon-button:hover {
    background: var(--select-bg);
    opacity: 0.8;
}

.main-clock {
    text-align: center;
    animation: fadeIn 1s ease-out;
}

.main-clock .time {
    font-size: 5rem;
    font-weight: 700;
    letter-spacing: 2px;
    color: #ffffff;        /* 添加特定颜色 */
    opacity: 0.8;         /* 添加透明度控制（0.9 = 90%不透明） */
}

.main-clock .date {
    font-size: 1.5rem;
    opacity: 0.8;
    margin-top: 0.5rem;
}

.world-clocks {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
    justify-content: center;
}

.world-clock {
    text-align: center;
    animation: slideUp 0.5s ease-out;
}

.timezone-select {
    background: var(--select-bg);
    border: none;
    color: var(--text-color);
    padding: 0.5rem;
    border-radius: 6px;
    margin-bottom: 0.5rem;
    backdrop-filter: blur(10px);
    transition: background-color var(--transition-duration),
                color var(--transition-duration);
    text-align: center;  /* 添加这行来居中对齐文本 */
}

.world-time {
    font-size: 3rem;
}

.fullscreen-hint {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.8rem;
    opacity: 0;
    transition: opacity var(--transition-duration);
}

.fullscreen-hint:hover {
    opacity: 0.6;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 768px) {
    .main-clock .time {
        font-size: 3rem;
    }
    
    .world-clocks {
        flex-direction: column;
        gap: 1rem;
    }
}

/* 修改时区选择器的样式 */
select {
    background: #1a1a1a;
    color: var(--text-color);
    border: none;
    padding: 5px 10px;
    border-radius: 8px;
    font-size: 1em;
    cursor: pointer;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    opacity: 0.5;
    transition: opacity 0.3s ease;
    -webkit-appearance: none;  /* 添加这行 */
    -moz-appearance: none;     /* 添加这行 */
    text-align-last: center;  /* 使用 text-align-last 来控制选择框中的文本居中 */
    text-align: center;  /* 让选择框中的文本居中 */
}

/* 悬停时提高不透明度 */
select:hover {
    opacity: 1;
}

/* 确保选项的背景色和文字颜色正确 */
select option {
    background-color: #1a1a1a !important;  /* 添加 !important */
    color: var(--text-color);
    text-align: left;  /* 让下拉选项左对齐 */
}

/* 深色主题特别处理 */
{
    background-color: #1a1a1a;
}

/* 浅色主题特别处理 */
{
    background-color: #1a1a1a;
}