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

:root {
    --primary-color: #0099ff;
    --primary-hover: #0077cc;
    --accent-color: #ff6b9d;
    --background: #ffffff;
    --surface: #fafafa;
    --surface-dark: #f0f0f0;
    --text-primary: #000000;
    --text-secondary: #666666;
    --border: #e5e7eb;
    --border-light: #cccccc;
    --shadow: rgba(0, 0, 0, 0.05);
    --shadow-lg: rgba(0, 0, 0, 0.08);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

/* 像素字体 */
h1, h2, h3, .pixel-text, .tab {
    font-family: 'Press Start 2P', cursive;
    line-height: 1.8;
    letter-spacing: 0.05em;
}

.container {
    max-width: 1600px;
    margin: 0 auto;
    padding: 0;
}

/* Header */
header {
    padding: 30px 40px 25px 40px; /* 增加 top padding 给 logo 留空间 */
    background: transparent;
    color: var(--text-primary);
    border-bottom: 1px dashed var(--border);
    position: relative;
}

.site-logo {
    position: absolute;
    top: 25px; /* 与 header padding-top 对齐 */
    left: 20px;
    z-index: 10;
}

.site-logo img {
    display: block;
    width: 32px;
    height: 32px;
    transition: transform 0.2s ease;
}

.site-logo img:hover {
    transform: scale(1.1);
}

.header-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 40px;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.header-text {
    text-align: left;
}

.header-text h1 {
    font-size: 1.8rem;
    margin-bottom: 12px;
    letter-spacing: 0.05em;
    line-height: 1.4;
    color: var(--text-primary);
}

.subtitle {
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.8;
    color: var(--text-secondary);
    font-family: 'Press Start 2P', cursive;
    letter-spacing: 0.05em;
}

.header-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.header-image img {
    max-width: 100%;
    max-height: 200px;
    width: auto;
    height: auto;
    border-radius: 0;
    border: 1px solid var(--border);
    image-rendering: pixelated;
    image-rendering: -moz-crisp-edges;
    image-rendering: crisp-edges;
    object-fit: contain;
}

/* Main */
main {
    padding: 10px 20px;
}

/* Upload Section */
.upload-section {
    max-width: 800px;
    margin: 40px auto;
}

.upload-area {
    background: transparent;
    border: 2px dashed var(--border);
    border-radius: 0;
    padding: 70px 50px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-bottom: 40px;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: rgba(0, 153, 255, 0.02);
    border-width: 2px;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: rgba(0, 153, 255, 0.05);
    border-style: solid;
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.upload-text {
    font-size: 1.2rem;
    margin-bottom: 12px;
    font-weight: 500;
}

.upload-link {
    color: var(--primary-color);
    font-weight: 600;
    cursor: pointer;
}

.upload-link:hover {
    text-decoration: underline;
}

.upload-or {
    color: var(--text-primary);
}

.upload-hint {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-top: 10px;
}

/* Example Images */
.example-images {
    text-align: center;
}

.example-images > p {
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.example-btns {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.example-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 0;
    cursor: pointer;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    font-weight: 400;
}

.example-btn:hover {
    background: var(--text-primary);
    color: #ffffff;
    border-color: var(--text-primary);
}

/* Workspace - 侧边栏布局 */
.workspace {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: 20px;
    margin-bottom: 30px;
    align-items: start;
    min-height: calc(100vh - 200px); /* 增加预留空间，考虑 header + logo + main padding */
}

/* 左侧控制面板 */
.controls-sidebar {
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 0;
    padding: 24px;
    position: sticky;
    top: 20px;
    max-height: calc(100vh - 40px);
    overflow-y: auto;
}

/* 自定义滚动条 */
.controls-sidebar::-webkit-scrollbar {
    width: 6px;
}

.controls-sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.controls-sidebar::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 0;
}

.controls-sidebar::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

.tabs {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 20px;
}

.tab {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 12px 16px;
    cursor: pointer;
    font-size: 0.65rem;
    transition: all 0.3s ease;
    border-radius: 0;
    text-align: left;
    text-transform: uppercase;
}

.tab:hover {
    background: transparent;
    color: var(--text-primary);
    border-color: var(--text-primary);
}

.tab.active {
    background: var(--text-primary);
    color: #ffffff;
    border-color: var(--text-primary);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

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

.control-group > label:first-child {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.9rem;
}

.value {
    color: var(--primary-color);
    font-weight: 700;
    font-family: 'Courier New', monospace;
}

input[type="range"] {
    width: 100%;
    height: 6px;
    background: var(--surface-dark);
    border-radius: 10px;
    outline: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--text-primary);
    border-radius: 0;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 1px solid var(--text-primary);
}

input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--text-primary);
    transform: scale(1.1);
}

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--text-primary);
    border-radius: 0;
    cursor: pointer;
    border: 1px solid var(--text-primary);
    transition: all 0.3s ease;
}

input[type="range"]::-moz-range-thumb:hover {
    background: var(--text-primary);
    transform: scale(1.1);
}

select {
    width: 100%;
    padding: 10px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 0;
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

select:hover,
select:focus {
    border-color: var(--text-primary);
    outline: none;
    background: transparent;
}

.checkbox-label {
    display: flex !important;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-weight: 500 !important;
}

input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

/* Buttons */
.btn-primary,
.btn-secondary {
    width: 100%;
    padding: 12px 20px;
    border-radius: 0;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--text-primary);
    color: white;
    margin-bottom: 10px;
    border: 1px solid var(--text-primary);
}

.btn-primary:hover {
    background: transparent;
    color: var(--text-primary);
    border-color: var(--text-primary);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: transparent;
    color: var(--text-primary);
    border-color: var(--text-primary);
}

/* Palette Preview */
.palette-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 15px 0;
    padding: 15px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 0;
    min-height: 50px;
}

.palette-color {
    width: 32px;
    height: 32px;
    border-radius: 0;
    border: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.3s ease;
}

.palette-color:hover {
    transform: scale(1.05);
    border-color: var(--text-primary);
}

/* Download Info */
.download-info {
    background: transparent;
    padding: 15px;
    border-radius: 0;
    margin-bottom: 15px;
    border: 1px solid var(--border);
    border-left: 3px solid var(--text-primary);
}

.download-info p {
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.download-info strong {
    color: var(--text-primary);
}

/* 右侧预览区 */
.preview-area {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    align-items: stretch;
    height: 100%;
}

.canvas-container {
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 0;
    padding: 12px;
    transition: border-color 0.3s ease;
    min-width: 0;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.canvas-container:hover {
    border-color: var(--text-primary);
}

.canvas-wrapper {
    text-align: center;
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.canvas-wrapper h3 {
    margin-bottom: 8px;
    padding-bottom: 5px;
    border-bottom: 1px dashed var(--border);
    color: var(--text-secondary);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    flex-shrink: 0;
}

.canvas-wrapper.pixel-result h3 {
    color: var(--primary-color);
    font-weight: bold;
}

.canvas-wrapper canvas {
    border-radius: 0;
    /* 使用棋盘格背景显示透明区域 */
    background-color: #ffffff;
    background-image: 
        linear-gradient(45deg, #e0e0e0 25%, transparent 25%),
        linear-gradient(-45deg, #e0e0e0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #e0e0e0 75%),
        linear-gradient(-45deg, transparent 75%, #e0e0e0 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    border: 1px solid var(--border);
    image-rendering: pixelated;
    image-rendering: -moz-crisp-edges;
    image-rendering: crisp-edges;
    display: block;
    margin: 0 auto;
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    flex: 1;
    object-fit: contain;
}

#originalCanvas {
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    object-fit: contain;
}

#pixelCanvas {
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    object-fit: contain;
}

.canvas-info {
    margin-top: 6px;
    color: var(--text-secondary);
    font-size: 0.75rem;
    font-family: 'Courier New', monospace;
    flex-shrink: 0;
}

/* Demos */
.demos {
    margin: 60px 20px;
}

.demos h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

.demo-card {
    background: transparent;
    padding: 40px 30px;
    border-radius: 0;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--border);
}

.demo-card:hover {
    border-color: var(--text-primary);
    background: transparent;
}

.demo-label {
    font-size: 2rem;
    margin-bottom: 15px;
}

.demo-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 20px;
}

.demo-image {
    max-width: 100%;
    height: auto;
    margin-top: 15px;
    display: block;
    image-rendering: pixelated;
    image-rendering: -moz-crisp-edges;
    image-rendering: crisp-edges;
}

/* Info Section */
.info-section {
    background: transparent;
    padding: 40px;
    border-radius: 0;
    margin: 40px 20px 60px;
    border: 1px solid var(--border);
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.info-section h2 {
    margin-bottom: 25px;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.info-content p {
    margin-bottom: 15px;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* Footer */
footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-secondary);
    border-top: 1px solid var(--border);
    background: transparent;
    font-size: 0.9rem;
}

.footer-links {
    margin-bottom: 20px;
}

.blog-link {
    display: inline-block;
    padding: 10px 20px;
    background: transparent;
    color: var(--text-primary);
    text-decoration: none;
    border: 1px dashed var(--border);
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

.blog-link:hover {
    border-style: solid;
    background: var(--bg-primary);
}

/* Responsive */
@media (max-width: 1024px) {
    header {
        padding: 30px 30px 25px 30px;
    }

    .header-content {
        gap: 30px;
    }

    .header-text h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.55rem;
    }

    .header-image img {
        max-height: 180px;
    }

    .workspace {
        grid-template-columns: 280px 1fr;
        min-height: calc(100vh - 180px); /* 考虑 header + logo 空间 */
    }
    
    .preview-area {
        gap: 15px;
    }
    
    .canvas-container {
        padding: 12px;
    }
}

@media (max-width: 768px) {
    header {
        padding: 25px 20px 20px 20px;
    }

    .site-logo {
        top: 20px;
        left: 15px;
    }

    .site-logo img {
        width: 28px;
        height: 28px;
    }

    .header-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .header-text {
        text-align: center;
    }

    .header-text h1 {
        font-size: 1.3rem;
        margin-bottom: 10px;
    }

    .subtitle {
        font-size: 0.5rem;
    }

    .header-image img {
        max-width: 70%;
        max-height: 150px;
    }
    
    .upload-area {
        padding: 50px 30px;
    }

    .workspace {
        grid-template-columns: 1fr;
        min-height: auto;
    }
    
    .controls-sidebar {
        position: relative;
        top: 0;
        max-height: none;
        overflow-y: visible;
    }
    
    .preview-area {
        display: flex;
        flex-direction: column-reverse;
        gap: 20px;
        height: auto;
    }
    
    .canvas-container {
        height: auto;
    }
    
    .canvas-wrapper {
        flex: none;
    }
    
    .canvas-wrapper canvas,
    #originalCanvas,
    #pixelCanvas {
        max-height: 500px;
        flex: none;
    }

    .tabs {
        flex-direction: row;
        overflow-x: auto;
    }

    .tab {
        flex-shrink: 0;
        min-width: 100px;
        text-align: center;
        font-size: 0.6rem;
    }

    .demo-grid {
        grid-template-columns: 1fr;
    }

    .info-section {
        padding: 25px;
        margin: 20px;
    }
    
    .demos h2, .info-section h2 {
        font-size: 1.2rem;
    }
}

@media (max-width: 480px) {
    header {
        padding: 22px 15px 18px 15px;
    }

    .site-logo {
        top: 18px;
        left: 12px;
    }

    .site-logo img {
        width: 24px;
        height: 24px;
    }

    .header-content {
        gap: 15px;
    }
    
    .header-text h1 {
        font-size: 1rem;
        margin-bottom: 8px;
    }
    
    .subtitle {
        font-size: 0.45rem;
    }

    .header-image img {
        max-width: 80%;
        max-height: 120px;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .canvas-container {
        padding: 20px;
    }
    
    .tab {
        font-size: 0.55rem;
        padding: 10px 12px;
    }
}

/* 加载动画 */
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}