/* ==================== 全局样式 ==================== */
:root {
    /* 颜色系统 */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);

    --bg-dark: #0f0f23;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-card-hover: rgba(255, 255, 255, 0.08);

    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);

    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);

    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    transition: opacity 0.15s ease;
}

/* 动态背景 */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(circle at 20% 30%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(67, 233, 123, 0.1) 0%, transparent 50%);
    z-index: -1;
    animation: backgroundPulse 15s ease-in-out infinite;
}

@keyframes backgroundPulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.8;
    }
}

/* ==================== 容器 ==================== */
.container {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

/* ==================== 头部 ==================== */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-md);
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-img {
    width: 40px;
    height: 40px;
    object-fit: contain;
    animation: logoFloat 3s ease-in-out infinite;
}

@keyframes logoFloat {

    0%,
    100% {
        transform: translateY(0px);
    }

    50% {
        transform: translateY(-5px);
    }
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    border: 1px solid var(--border-color);
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #feca57;
    animation: statusPulse 2s ease-in-out infinite;
}

.status-indicator.ready .status-dot {
    background: #43e97b;
}

.status-indicator.error .status-dot {
    background: #ff6b6b;
    animation: none;
}

@keyframes statusPulse {

    0%,
    100% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.6;
        transform: scale(0.9);
    }
}

.status-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* 语言切换按钮 */
.lang-btn {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: inherit;
    margin-right: var(--spacing-md);
}

.lang-btn:hover {
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.lang-btn:active {
    transform: translateY(0);
}

/* ==================== 主内容 ==================== */
.main-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: var(--spacing-lg);
}

/* ==================== 画布容器 ==================== */
.canvas-container {
    position: relative;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    aspect-ratio: 16 / 9;
    box-shadow: var(--shadow-lg);
}

#videoElement {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transform: scaleX(-1);
    opacity: 0.3;
}

#drawingCanvas,
#handCanvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

#handCanvas {
    pointer-events: none;
}

/* 提示覆盖层 */
.hint-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 15, 35, 0.9);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.hint-overlay.hidden {
    opacity: 0;
    visibility: hidden;
}

.hint-content {
    text-align: center;
    animation: hintFloat 3s ease-in-out infinite;
}

@keyframes hintFloat {

    0%,
    100% {
        transform: translateY(0px);
    }

    50% {
        transform: translateY(-10px);
    }
}

.hint-content svg {
    margin-bottom: var(--spacing-md);
    filter: drop-shadow(0 4px 12px rgba(102, 126, 234, 0.5));
}

.hint-content h2 {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-sm);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hint-content p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ==================== 控制面板 ==================== */
.control-panel {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.control-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    backdrop-filter: blur(10px);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.control-section:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.control-section h3 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    font-weight: 600;
}

.control-group {
    margin-bottom: var(--spacing-md);
}

.control-group:last-child {
    margin-bottom: 0;
}

.control-group label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.control-group .value {
    font-weight: 600;
    color: var(--text-primary);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 滑块样式 */
input[type="range"] {
    width: 100%;
    height: 6px;
    background: var(--bg-card-hover);
    border-radius: var(--radius-xl);
    outline: none;
    appearance: none;
    -webkit-appearance: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-gradient);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.5);
    transition: transform var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--primary-gradient);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.5);
    transition: transform var(--transition-fast);
}

input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.2);
}

/* 颜色选择器 */
.color-palette {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-xs);
}

.color-btn {
    width: 100%;
    aspect-ratio: 1;
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
}

.color-btn::before {
    content: '';
    position: absolute;
    inset: -4px;
    border-radius: var(--radius-sm);
    background: var(--primary-gradient);
    opacity: 0;
    transition: opacity var(--transition-fast);
    z-index: -1;
}

.color-btn:hover {
    transform: scale(1.1);
}

.color-btn.active {
    border-color: white;
    box-shadow: 0 0 0 2px var(--bg-dark), 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* 按钮组 */
.button-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: inherit;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(102, 126, 234, 0.5);
}

.btn-primary:active {
    transform: translateY(0);
}

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

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateY(-2px);
}

/* 手势指南 */
.gesture-guide {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.gesture-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm);
    background: var(--bg-card-hover);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.gesture-item:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateX(4px);
}

.gesture-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-card);
    border-radius: var(--radius-md);
}

.gesture-desc {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.gesture-desc strong {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.gesture-desc span {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ==================== 页脚 ==================== */
.footer {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .control-panel {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        grid-auto-flow: dense;
    }
}

@media (max-width: 768px) {
    .container {
        padding: var(--spacing-sm);
    }

    .header {
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    .hint-content h2 {
        font-size: 1.4rem;
    }

    .hint-content p {
        font-size: 1rem;
    }
}

/* ==================== 动画效果 ==================== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.control-section {
    animation: fadeIn 0.5s ease backwards;
}

.control-section:nth-child(1) {
    animation-delay: 0.1s;
}

.control-section:nth-child(2) {
    animation-delay: 0.2s;
}

.control-section:nth-child(3) {
    animation-delay: 0.3s;
}