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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.description {
    font-size: 1.1rem;
    opacity: 0.9;
    max-width: 800px;
    margin: 0 auto;
}

.mobile-tips {
    font-size: 0.9rem;
    opacity: 0.8;
    max-width: 600px;
    margin: 10px auto 0;
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.visualization-container {
    display: flex;
    gap: 30px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.track-container {
    flex: 1;
    min-width: 600px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

#trackCanvas {
    width: 600px;
    height: 600px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.2);
    /* 确保Canvas尺寸不会因为DPR或其他因素变化 */
    max-width: 600px;
    max-height: 600px;
    min-width: 600px;
    min-height: 600px;
}

.track-info {
    margin-top: 20px;
    display: flex;
    gap: 30px;
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 15px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.info-item {
    text-align: center;
    color: white;
}

.info-item .label {
    display: block;
    font-size: 0.9rem;
    opacity: 0.8;
    margin-bottom: 5px;
}

.info-item span:last-child {
    font-size: 1.2rem;
    font-weight: bold;
}

.controls {
    flex: 0 0 300px;
    background: rgba(255, 255, 255, 0.95);
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    height: fit-content;
}

.control-group {
    margin-bottom: 20px;
}

.control-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.control-group input[type="number"] {
    width: 100%;
    padding: 10px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.control-group input[type="number"]:focus {
    outline: none;
    border-color: #667eea;
}

.control-group input[type="range"] {
    width: 100%;
    margin: 10px 0;
}

#speedValue {
    display: inline-block;
    margin-left: 10px;
    font-weight: 600;
    color: #667eea;
}

.control-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    flex: 1;
    min-width: 80px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #f8f9fa;
    color: #6c757d;
    border: 2px solid #e9ecef;
}

.btn-secondary:hover:not(:disabled) {
    background: #e9ecef;
    transform: translateY(-2px);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

.explanation {
    background: rgba(255, 255, 255, 0.95);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.explanation h2 {
    text-align: center;
    margin-bottom: 25px;
    color: #333;
    font-size: 1.8rem;
}

.explanation-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.explanation-item {
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    border-left: 4px solid #667eea;
}

.explanation-item h3 {
    color: #667eea;
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.explanation-item p {
    color: #666;
    line-height: 1.6;
}

/* 基础响应式设计 */
@media (max-width: 1200px) {
    .container {
        max-width: 95%;
        padding: 15px;
    }
    
    .visualization-container {
        gap: 20px;
    }
    
    #trackCanvas {
        width: 500px;
        height: 500px;
        max-width: 500px;
        max-height: 500px;
        min-width: 500px;
        min-height: 500px;
    }
}

@media (max-width: 1024px) {
    .container {
        max-width: 98%;
        padding: 12px;
    }
    
    header h1 {
        font-size: 2.2rem;
    }
    
    .description {
        font-size: 1rem;
    }
    
    #trackCanvas {
        width: 450px;
        height: 450px;
        max-width: 450px;
        max-height: 450px;
        min-width: 450px;
        min-height: 450px;
    }
    
    .controls {
        flex: 0 0 280px;
        padding: 20px;
    }
}

@media (max-width: 768px) {
    .mobile-tips {
        font-size: 0.8rem;
        padding: 6px 12px;
        margin: 8px auto 0;
    }
    
    .visualization-container {
        flex-direction: column;
        gap: 20px;
    }
    
    .track-container {
        min-width: auto;
        order: 2;
    }
    
    .controls {
        flex: none;
        order: 1;
        width: 100%;
        max-width: 500px;
        margin: 0 auto;
    }
    
    #trackCanvas {
        width: 350px;
        height: 350px;
        max-width: 350px;
        max-height: 350px;
        min-width: 350px;
        min-height: 350px;
    }
    
    .track-info {
        flex-direction: column;
        gap: 15px;
        padding: 15px;
    }
    
    .control-buttons {
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .btn {
        padding: 10px 20px;
        font-size: 0.95rem;
        min-width: 70px;
    }
    
    .explanation-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .explanation {
        padding: 20px;
    }
    
    .explanation h2 {
        font-size: 1.6rem;
    }
    
    .explanation-item {
        padding: 15px;
    }
    
    .explanation-item h3 {
        font-size: 1.1rem;
    }
    
    .explanation-item p {
        font-size: 0.95rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    header {
        margin-bottom: 25px;
    }
    
    header h1 {
        font-size: 1.8rem;
        margin-bottom: 10px;
    }
    
    .description {
        font-size: 0.9rem;
        line-height: 1.5;
    }
    
    #trackCanvas {
        width: 300px;
        height: 300px;
        max-width: 300px;
        max-height: 300px;
        min-width: 300px;
        min-height: 300px;
    }
    
    .track-info {
        padding: 12px;
        gap: 12px;
    }
    
    .info-item .label {
        font-size: 0.8rem;
    }
    
    .info-item span:last-child {
        font-size: 1.1rem;
    }
    
    .controls {
        padding: 15px;
    }
    
    .control-group {
        margin-bottom: 15px;
    }
    
    .control-group label {
        font-size: 0.9rem;
        margin-bottom: 6px;
    }
    
    .control-group input[type="number"] {
        padding: 8px;
        font-size: 0.9rem;
    }
    
    .btn {
        padding: 8px 16px;
        font-size: 0.9rem;
        min-width: 60px;
    }
    
    .explanation {
        padding: 15px;
    }
    
    .explanation h2 {
        font-size: 1.4rem;
        margin-bottom: 20px;
    }
    
    .explanation-item {
        padding: 12px;
    }
    
    .explanation-item h3 {
        font-size: 1rem;
    }
    
    .explanation-item p {
        font-size: 0.9rem;
    }
}

@media (max-width: 360px) {
    header h1 {
        font-size: 1.6rem;
    }
    
    .description {
        font-size: 0.85rem;
    }
    
    #trackCanvas {
        width: 280px;
        height: 280px;
        max-width: 280px;
        max-height: 280px;
        min-width: 280px;
        min-height: 280px;
    }
    
    .controls {
        padding: 12px;
    }
    
    .btn {
        padding: 6px 12px;
        font-size: 0.85rem;
        min-width: 50px;
    }
}

/* 触摸设备优化 */
@media (hover: none) and (pointer: coarse) {
    .btn {
        min-height: 44px; /* 触摸友好的最小高度 */
        touch-action: manipulation; /* 优化触摸响应 */
    }
    
    .control-group input[type="range"] {
        min-height: 44px;
        touch-action: pan-x; /* 只允许水平滑动 */
    }
    
    .control-group input[type="number"] {
        min-height: 44px;
        font-size: 16px; /* 防止iOS缩放 */
    }
    
    /* 增加触摸区域 */
    .track-info {
        padding: 20px;
    }
    
    .info-item {
        padding: 10px;
        min-height: 44px;
        display: flex;
        flex-direction: column;
        justify-content: center;
    }
    
    /* 触摸友好的预设按钮 */
    .preset-btn {
        min-height: 44px;
        min-width: 60px;
    }
    
    /* 触摸友好的Canvas */
    #trackCanvas {
        touch-action: manipulation;
        cursor: pointer;
    }
}

/* 横屏模式优化 */
@media (orientation: landscape) and (max-height: 600px) {
    header {
        margin-bottom: 20px;
    }
    
    header h1 {
        font-size: 1.8rem;
        margin-bottom: 8px;
    }
    
    .description {
        font-size: 0.9rem;
        margin-bottom: 15px;
    }
    
    .visualization-container {
        margin-bottom: 20px;
    }
    
    .explanation {
        padding: 15px;
    }
    
    .explanation h2 {
        font-size: 1.4rem;
        margin-bottom: 15px;
    }
}

/* 重复点弹窗样式 */
.duplicate-point-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    animation: fadeIn 0.3s ease-in-out;
}

.modal-content {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    max-width: 500px;
    text-align: center;
    animation: slideIn 0.3s ease-out;
    margin: 20px;
}

.modal-content h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.modal-content h4 {
    color: #333;
    margin: 20px 0 10px 0;
    font-size: 1.1rem;
    text-align: left;
}

.modal-content p {
    color: #666;
    margin-bottom: 10px;
    line-height: 1.5;
}

.duplicate-data {
    margin: 20px 0;
    text-align: left;
}

.data-output {
    width: 100%;
    height: 120px;
    padding: 10px;
    border: 2px solid #e1e5e9;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.4;
    background: #f8f9fa;
    color: #333;
    resize: vertical;
    white-space: pre;
}

.modal-buttons {
    margin-top: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

.modal-buttons .btn {
    min-width: 100px;
}

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

@keyframes slideIn {
    from { 
        transform: translateY(-50px);
        opacity: 0;
    }
    to { 
        transform: translateY(0);
        opacity: 1;
    }
}

/* 弹窗响应式设计 */
@media (max-width: 768px) {
    .modal-content {
        padding: 20px;
        max-width: 90%;
        margin: 15px;
    }
    
    .modal-content h3 {
        font-size: 1.3rem;
    }
    
    .modal-content p {
        font-size: 0.95rem;
    }
    
    /* 移动端弹窗优化 */
    .duplicate-data {
        margin: 15px 0;
    }
    
    .data-output {
        height: 100px;
        font-size: 0.8rem;
    }
    
    .modal-buttons .btn {
        min-height: 44px;
        padding: 12px 20px;
    }
}

/* 移动端性能优化 */
@media (max-width: 768px) {
    /* 减少阴影和模糊效果以提高性能 */
    .track-container {
        box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    }
    
    #trackCanvas {
        box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
        backdrop-filter: blur(5px);
    }
    
    .controls {
        box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    }
    
    .explanation {
        box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    }
}

/* 平板设备优化 */
@media (min-width: 769px) and (max-width: 1024px) {
    .visualization-container {
        gap: 25px;
    }
    
    .track-container {
        min-width: 500px;
    }
    
    .controls {
        flex: 0 0 320px;
        padding: 30px;
    }
    
    .preset-buttons {
        gap: 10px;
    }
    
    .preset-btn {
        padding: 10px 18px;
        font-size: 1rem;
    }
}

/* 横屏手机优化 */
@media (max-width: 768px) and (orientation: landscape) {
    header {
        margin-bottom: 15px;
    }
    
    header h1 {
        font-size: 1.6rem;
        margin-bottom: 8px;
    }
    
    .description {
        font-size: 0.9rem;
        margin-bottom: 15px;
    }
    
    .visualization-container {
        flex-direction: row;
        gap: 15px;
        margin-bottom: 20px;
    }
    
    .track-container {
        order: 1;
        flex: 1;
    }
    
    .controls {
        order: 2;
        flex: 0 0 250px;
        max-width: none;
        margin: 0;
    }
    
    #trackCanvas {
        width: 280px;
        height: 280px;
        max-width: 280px;
        max-height: 280px;
        min-width: 280px;
        min-height: 280px;
    }
    
    .explanation {
        display: none; /* 横屏时隐藏说明部分以节省空间 */
    }
}

/* 高DPI屏幕优化 */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
    #trackCanvas {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
    }
}