:root {
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a2e;
    --bg-card: #16213e;
    --bg-input: #0a0a1a;
    --border: #334155;
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-blue: #38bdf8;
    --accent-purple: #a78bfa;
    --accent-green: #34d399;
    --accent-red: #f87171;
    --accent-orange: #fb923c;
    --accent-yellow: #fbbf24;
    --glow: 0 0 20px rgba(56, 189, 248, 0.15);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

/* 顶部导航 */
.header {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(12px);
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 28px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-subtitle {
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 1px;
}

/* 标签页 */
.tab-nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    gap: 4px;
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 14px 20px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 6px;
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(56, 189, 248, 0.05);
}

.tab-btn.active {
    color: var(--accent-blue);
    border-bottom-color: var(--accent-blue);
}

.tab-icon {
    font-size: 16px;
}

/* 主内容 */
.main-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 24px;
}

.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

/* 卡片 */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--glow);
}

.card-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* 上传区域 */
.upload-zone {
    border: 2px dashed var(--border);
    border-radius: 8px;
    padding: 32px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    position: relative;
}

.upload-zone:hover {
    border-color: var(--accent-blue);
    background: rgba(56, 189, 248, 0.03);
}

.upload-zone.dragover {
    border-color: var(--accent-green);
    background: rgba(52, 211, 153, 0.05);
}

.upload-zone input[type="file"] {
    display: none;
}

.upload-icon {
    font-size: 36px;
    margin-bottom: 8px;
}

.upload-text {
    font-size: 14px;
    color: var(--text-secondary);
}

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

.upload-hint {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 4px;
}

/* 文本输入区 */
textarea.data-input {
    width: 100%;
    min-height: 200px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 12px;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    line-height: 1.6;
    resize: vertical;
    transition: border-color 0.2s;
}

textarea.data-input:focus {
    outline: none;
    border-color: var(--accent-blue);
}

textarea.data-input::placeholder {
    color: var(--text-muted);
}

/* 控件 */
.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: flex-end;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.control-group label {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

.control-group select,
.control-group input[type="number"] {
    background: var(--bg-input);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 13px;
}

.control-group input[type="range"] {
    width: 120px;
    accent-color: var(--accent-blue);
}

.btn {
    padding: 10px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: white;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(56, 189, 248, 0.3);
}

.btn-primary:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

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

.btn-secondary:hover {
    border-color: var(--accent-blue);
}

/* 加载/错误 */
.loading {
    display: none;
    text-align: center;
    padding: 40px;
}

.loading.active {
    display: block;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border);
    border-top-color: var(--accent-blue);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 16px;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-text {
    color: var(--text-secondary);
    font-size: 14px;
}

.error-message {
    display: none;
    background: rgba(248, 113, 113, 0.1);
    border: 1px solid var(--accent-red);
    border-radius: 8px;
    padding: 12px 16px;
    color: var(--accent-red);
    font-size: 13px;
    margin-top: 12px;
}

.error-message.active {
    display: block;
}

.success-message {
    background: rgba(52, 211, 153, 0.1);
    border: 1px solid var(--accent-green);
    border-radius: 8px;
    padding: 12px 16px;
    color: var(--accent-green);
    font-size: 13px;
    margin-bottom: 16px;
}

/* 结果区域 */
.result-section {
    animation: fadeIn 0.4s ease;
}

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

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

.image-result {
    text-align: center;
    margin: 16px 0;
}

.image-result img {
    max-width: 100%;
    border-radius: 8px;
    border: 1px solid var(--border);
}

/* 统计卡片 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 12px;
    margin: 16px 0;
}

.stat-card {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    text-align: center;
}

.stat-value {
    font-size: 22px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.stat-label {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 4px;
    text-transform: uppercase;
}

/* 数据表格 */
.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 16px;
    font-size: 12px;
}

.data-table th {
    background: var(--bg-input);
    color: var(--text-secondary);
    padding: 8px 12px;
    text-align: left;
    border-bottom: 1px solid var(--border);
    font-weight: 600;
    position: sticky;
    top: 0;
}

.data-table td {
    padding: 6px 12px;
    border-bottom: 1px solid rgba(51, 65, 85, 0.3);
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
}

.data-table tr:hover td {
    background: rgba(56, 189, 248, 0.03);
}

.table-scroll {
    max-height: 400px;
    overflow-y: auto;
    border-radius: 8px;
    border: 1px solid var(--border);
}

/* 双栏布局 */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

/* 输入提示 */
.format-hint {
    background: rgba(56, 189, 248, 0.05);
    border: 1px solid rgba(56, 189, 248, 0.15);
    border-radius: 6px;
    padding: 10px 14px;
    margin: 8px 0 16px;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.format-hint code {
    background: var(--bg-input);
    padding: 1px 6px;
    border-radius: 3px;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent-blue);
}

@media (max-width: 768px) {
    .two-col {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 速度约束优化拟合按钮 */
.btn-accent {
    background: linear-gradient(135deg, #f59e0b, #ef4444);
    color: white;
}

.btn-accent:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(245, 158, 11, 0.3);
}

/* 自适应拟合按钮 */
.btn-adaptive {
    background: linear-gradient(135deg, #34d399, #06b6d4);
    color: white;
}

.btn-adaptive:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(52, 211, 153, 0.3);
}

/* 迭代拟合按钮 */
.btn-iterative {
    background: linear-gradient(135deg, #a78bfa, #818cf8);
    color: white;
}

.btn-iterative:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(167, 139, 250, 0.3);
}

/* 精确速度收敛拟合按钮 */
.btn-precision {
    background: linear-gradient(135deg, #22d3ee, #0ea5e9);
    color: white;
}

.btn-precision:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(34, 211, 238, 0.3);
}

/* 速度约束参数面板 */
.constrained-params {
    display: none;
    background: rgba(245, 158, 11, 0.05);
    border: 1px solid rgba(245, 158, 11, 0.2);
    border-radius: 8px;
    padding: 16px;
    margin-top: 16px;
    animation: fadeIn 0.3s ease;
}

.constrained-params.active {
    display: block;
}

.params-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--accent-orange);
    margin-bottom: 12px;
}

.params-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.param-item label {
    display: block;
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 6px;
    font-weight: 500;
}

.param-item label span {
    color: var(--accent-orange);
    font-family: 'JetBrains Mono', monospace;
    font-weight: 700;
}

.param-item input[type="range"] {
    width: 100%;
    accent-color: var(--accent-orange);
    height: 6px;
}

/* 速度特征分析展示 */
.velocity-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 12px;
    margin: 16px 0;
}

.feature-card {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 14px;
}

.feature-card .feature-title {
    font-size: 12px;
    font-weight: 600;
    color: var(--accent-orange);
    text-transform: uppercase;
    margin-bottom: 8px;
}

.feature-card .feature-row {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    padding: 3px 0;
    color: var(--text-secondary);
}

.feature-card .feature-row .feature-val {
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-weight: 500;
}

/* 拟合质量对比条 */
.quality-bar {
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    margin: 16px 0;
}

.quality-bar .quality-row {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.quality-bar .quality-row:last-child {
    margin-bottom: 0;
}

.quality-bar .quality-label {
    font-size: 12px;
    color: var(--text-secondary);
    min-width: 100px;
}

.quality-bar .quality-track {
    flex: 1;
    height: 8px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
    overflow: hidden;
}

.quality-bar .quality-fill {
    height: 100%;
    border-radius: 4px;
    transition: width 0.6s ease;
}

.quality-bar .quality-value {
    font-size: 12px;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    min-width: 80px;
    text-align: right;
}

@media (max-width: 768px) {
    .params-grid {
        grid-template-columns: 1fr;
    }
}