:root {
    --cn-font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", sans-serif;
    --bg-color: #000000;
    --text-color: #ffffff;
    --text-secondary: rgba(255, 255, 255, .85);
    --text-tertiary: rgba(255, 255, 255, .65);
    --toolbar-bg: rgba(255, 255, 255, .08);
    --toolbar-border: rgba(255, 255, 255, .15);
    --toolbar-hover: rgba(255, 255, 255, .12);
    --modal-bg: rgba(0, 0, 0, .7);
    --modal-content-bg: #1a1a1a;
    --modal-border: rgba(255, 255, 255, .15);
    --date-lunar-color: rgba(255, 255, 255, .55);
}

[data-theme="light"] {
    --bg-color: #ffffff;
    --text-color: #000000;
    --text-secondary: rgba(0, 0, 0, .85);
    --text-tertiary: rgba(0, 0, 0, .65);
    --toolbar-bg: rgba(0, 0, 0, .06);
    --toolbar-border: rgba(0, 0, 0, .12);
    --toolbar-hover: rgba(0, 0, 0, .08);
    --modal-bg: rgba(255, 255, 255, .7);
    --modal-content-bg: #f5f5f5;
    --modal-border: rgba(0, 0, 0, .12);
    --date-lunar-color: rgba(0, 0, 0, .5);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--cn-font);
    overflow: hidden;
    user-select: none;
    -webkit-user-select: none;
    transition: background-color .4s ease, color .4s ease;
}

#main-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    flex: 1;
    width: 100%;
    padding: 20px;
}

#time {
    font-size: clamp(60px, 25vw, 280px);
    font-weight: 700;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    letter-spacing: 0.02em;
    display: flex;
    align-items: center;
    gap: 4px;
    margin-bottom: 16px;
    line-height: 1;
}

.time-num {
    display: inline-block;
}

.colon {
    display: inline-block;
    animation: colonBlink 1s ease-in-out infinite;
    line-height: 1;
}

@keyframes colonBlink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.35; }
}

.seconds-colon {
    animation: colonBlink 1s ease-in-out infinite;
}

.seconds-part {
    opacity: 0.75;
}

.hide-seconds .seconds-colon,
.hide-seconds .seconds-part {
    display: none;
}

#date {
    font-size: clamp(16px, 4vw, 32px);
    color: var(--text-secondary);
    font-weight: 500;
    letter-spacing: 0.5px;
    text-align: center;
}

#date.hidden {
    display: none;
}

.date-num {
    font-weight: 600;
}

.date-cn {
    color: var(--text-tertiary);
    margin: 0 2px;
}

.lunar-part {
    color: var(--date-lunar-color);
    margin: 0 4px;
}

#stopwatch-area {
    display: none;
    flex-direction: column;
    align-items: center;
    margin-bottom: 16px;
}

#stopwatch-area.show {
    display: flex;
}

#stopwatch {
    font-size: clamp(40px, 12vw, 140px);
    font-weight: 700;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    letter-spacing: 2px;
}

.stopwatch-controls {
    display: flex;
    gap: 16px;
    margin-top: 12px;
}

.stopwatch-btn {
    padding: 10px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    background: rgba(66, 133, 244, 0.92);
    color: #ffffff;
}

.stopwatch-btn:hover {
    background: rgba(52, 103, 214, 0.92);
}

.stopwatch-btn.secondary {
    background: var(--toolbar-bg);
    color: var(--text-secondary);
}

.stopwatch-btn.secondary:hover {
    background: var(--toolbar-hover);
}

#countdown-area {
    display: none;
    flex-direction: column;
    align-items: center;
    margin-bottom: 16px;
}

#countdown-area.show {
    display: flex;
}

.countdown-label {
    font-size: clamp(14px, 3vw, 24px);
    color: var(--text-tertiary);
    margin-bottom: 6px;
    font-weight: 500;
}

#countdown {
    font-size: clamp(36px, 12vw, 140px);
    font-weight: 700;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    color: #ef4444;
    letter-spacing: 2px;
}

#countdown.finished {
    color: #22c55e;
}

.countdown-cancel {
    font-size: 13px;
    color: #4285f4;
    cursor: pointer;
    margin-top: 8px;
    font-weight: 500;
    padding: 4px 12px;
    border-radius: 4px;
    transition: background-color 0.2s ease;
}

.countdown-cancel:hover {
    background-color: rgba(66, 133, 244, 0.1);
}

#back-btn {
    position: fixed;
    top: 20px;
    left: 20px;
    padding: 10px 16px;
    background: var(--toolbar-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--toolbar-border);
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    z-index: 100;
}

#back-btn:hover {
    background: var(--toolbar-hover);
    color: var(--text-color);
}

#toolbar {
    display: none;
}

.toolbar-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 14px;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 70px;
    text-align: left;
}

.toolbar-btn:hover {
    background: var(--toolbar-hover);
    color: var(--text-color);
}

.toolbar-btn.active {
    background: rgba(66, 133, 244, 0.2);
    color: #4285f4;
}

.toolbar-divider {
    height: 1px;
    background: rgba(255, 255, 255, .15);
    margin: 4px 8px;
}

[data-theme="light"] .toolbar-divider {
    background: rgba(0, 0, 0, .12);
}

.mode-dropdown-wrapper {
    position: relative;
}

.mode-dropdown {
    position: absolute;
    bottom: 100%;
    right: 0;
    margin-bottom: 8px;
    padding: 4px;
    background: var(--modal-content-bg);
    border: 1px solid var(--modal-border);
    border-radius: 10px;
    display: none;
    flex-direction: column;
    min-width: 100px;
    z-index: 101;
}

.mode-dropdown.show {
    display: flex;
}

.mode-dropdown button {
    padding: 10px 14px;
    background: transparent;
    border: none;
    border-radius: 6px;
    color: var(--text-secondary);
    font-size: 13px;
    text-align: left;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.mode-dropdown button:hover {
    background: var(--toolbar-hover);
}

.theme-panel-wrapper {
    position: relative;
}

.theme-panel {
    position: absolute;
    bottom: 100%;
    right: 0;
    margin-bottom: 8px;
    padding: 8px;
    background: var(--modal-content-bg);
    border: 1px solid var(--modal-border);
    border-radius: 10px;
    display: none;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    min-width: 140px;
    z-index: 101;
}

.theme-panel.show {
    display: grid;
}

.theme-item {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.2s ease;
}

.theme-item:hover {
    transform: scale(1.1);
}

.theme-item.active {
    border-color: #4285f4;
}

.theme-item.dark { background: linear-gradient(135deg, #1a1a2e, #16213e); }
.theme-item.light { background: linear-gradient(135deg, #ffffff, #f5f5f5); }
.theme-item.blue { background: linear-gradient(135deg, #1e3a5f, #2d5a87); }
.theme-item.green { background: linear-gradient(135deg, #1e4d3d, #2d6b53); }
.theme-item.purple { background: linear-gradient(135deg, #2d1f4e, #4a2c6d); }
.theme-item.orange { background: linear-gradient(135deg, #5c3d2e, #8b5a2b); }

.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: var(--modal-bg);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-overlay.show {
    display: flex;
}

.modal-content {
    background: var(--modal-content-bg);
    border: 1px solid var(--modal-border);
    border-radius: 16px;
    padding: 24px;
    width: 90%;
    max-width: 420px;
    animation: slideUpIn 0.3s ease-out;
}

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

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: var(--text-tertiary);
    padding: 4px;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.modal-close:hover {
    color: var(--text-color);
    background: var(--toolbar-hover);
}

.tab-container {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
}

.tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    background: var(--toolbar-bg);
    color: var(--text-secondary);
}

.tab-btn.active {
    background: #4285f4;
    color: #ffffff;
}

.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-tertiary);
    margin-bottom: 6px;
}

.form-row {
    display: flex;
    gap: 8px;
}

.form-row .form-group {
    flex: 1;
}

.form-group input {
    width: 100%;
    padding: 10px 12px;
    font-size: 14px;
    border: 1px solid var(--toolbar-border);
    border-radius: 8px;
    background: var(--toolbar-bg);
    color: var(--text-color);
    outline: none;
    transition: all 0.2s ease;
    box-sizing: border-box;
}

.form-group input:focus {
    border-color: #4285f4;
    box-shadow: 0 0 0 3px rgba(66, 133, 244, 0.1);
}

.form-group input[type="number"] {
    text-align: center;
}

.modal-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.modal-btn {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.modal-btn.cancel {
    background: var(--toolbar-bg);
    color: var(--text-secondary);
}

.modal-btn.cancel:hover {
    background: var(--toolbar-hover);
}

.modal-btn.confirm {
    background: #4285f4;
    color: #ffffff;
}

.modal-btn.confirm:hover {
    background: #3367d6;
}

@media (max-width: 768px) {
    #time {
        font-size: clamp(50px, 28vw, 180px);
    }

    #date {
        font-size: clamp(14px, 4vw, 24px);
    }

    #countdown {
        font-size: clamp(28px, 10vw, 100px);
    }

    #stopwatch {
        font-size: clamp(32px, 10vw, 100px);
    }

    #toolbar {
        bottom: 16px;
        right: 16px;
        padding: 6px;
    }

    .toolbar-btn {
        padding: 8px 12px;
        font-size: 12px;
        min-width: 60px;
    }

    #back-btn {
        top: 16px;
        left: 16px;
        padding: 8px 12px;
        font-size: 13px;
    }

    .modal-content {
        padding: 20px;
        margin: 16px;
    }
}

@media (max-width: 480px) {
    #time {
        font-size: clamp(40px, 30vw, 120px);
    }

    #date {
        font-size: clamp(12px, 3.5vw, 20px);
    }

    #countdown {
        font-size: clamp(22px, 9vw, 70px);
    }

    #stopwatch {
        font-size: clamp(26px, 9vw, 80px);
    }
}