/* ==========================================
           深度学习 — 专有样式
           宽度继承全局 85%，风格延续 part3 的温暖杂志风
           ========================================== */

        /* ---- 章节二级标题变体 ---- */
        .chapter-section h3 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--primary-dark);
            margin: var(--space-lg) 0 var(--space-md);
            padding-left: var(--space-md);
            border-left: 3px solid var(--primary);
        }

        .chapter-section h4 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.05rem;
            font-weight: 600;
            color: var(--text-primary);
            margin: var(--space-md) 0 var(--space-sm);
        }

        /* ---- 定义卡 ---- */
        .def-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        .def-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            text-align: center;
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            position: relative;
            overflow: hidden;
        }

        .def-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            transition: opacity var(--transition-base);
        }

        .def-card:nth-child(1)::before {
            background: linear-gradient(90deg, #EC4899, #F472B6);
        }

        .def-card:nth-child(2)::before {
            background: linear-gradient(90deg, #3B82F6, #60A5FA);
        }

        .def-card:nth-child(3)::before {
            background: linear-gradient(90deg, #10B981, #34D399);
        }

        .def-card:nth-child(4)::before {
            background: linear-gradient(90deg, #8B5CF6, #A78BFA);
        }

        .def-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }

        .def-card:hover::before {
            opacity: 1;
        }

        .def-label {
            display: inline-block;
            font-size: 0.65rem;
            letter-spacing: 0.1em;
            padding: 3px 12px;
            border-radius: var(--radius-xl);
            margin-bottom: var(--space-sm);
        }

        .def-card h3 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.15rem;
            color: var(--text-primary);
            margin-bottom: 2px;
        }

        .def-en {
            font-size: 0.7rem;
            color: var(--text-muted);
            letter-spacing: 0.05em;
            margin-bottom: var(--space-sm);
        }

        .def-body {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.65;
            text-align: left;
        }

        .def-body strong {
            color: var(--primary);
        }

        /* ---- 核心技术卡片 ---- */
        .tech-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        .tech-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            position: relative;
        }

        .tech-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }

        .tech-card:nth-child(1) { border-top: 3px solid #6366F1; }
        .tech-card:nth-child(2) { border-top: 3px solid #F59E0B; }
        .tech-card:nth-child(3) { border-top: 3px solid #EC4899; }
        .tech-card:nth-child(4) { border-top: 3px solid #10B981; }
        .tech-card:nth-child(5) { border-top: 3px solid #8B5CF6; }
        .tech-card:nth-child(6) { border-top: 3px solid #EF4444; }

        .tech-card h3 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.1rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
        }

        .tech-desc {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.65;
        }

        /* ---- 工作流步骤 ---- */
        .flow-steps {
            display: flex;
            flex-wrap: wrap;
            gap: var(--space-md);
            justify-content: center;
            margin-bottom: var(--space-lg);
        }

        .flow-step {
            flex: 1;
            min-width: 160px;
            max-width: 220px;
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--space-lg) var(--space-md);
            text-align: center;
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            position: relative;
        }

        .flow-step:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
        }

        .flow-step:not(:last-child)::after {
            content: '→';
            position: absolute;
            right: -18px;
            top: 50%;
            transform: translateY(-50%);
            font-size: 1.2rem;
            color: var(--primary);
            font-weight: bold;
        }

        .flow-num {
            display: inline-block;
            width: 28px;
            height: 28px;
            line-height: 28px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary), var(--primary-dark));
            color: #fff;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: var(--space-sm);
        }

        .flow-step h4 {
            font-size: 0.9rem;
            color: var(--text-primary);
            margin-bottom: var(--space-xs);
        }

        .flow-step p {
            font-size: 0.75rem;
            color: var(--text-secondary);
            line-height: 1.5;
        }

        /* ---- 名词定义区块 ---- */
        .term-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
            gap: var(--space-md);
            margin-bottom: var(--space-lg);
        }

        .term-item {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--space-md) var(--space-lg);
            transition: all var(--transition-base);
            box-shadow: var(--shadow-sm);
        }

        .term-item:hover {
            border-color: var(--border-accent);
            transform: translateX(4px);
            box-shadow: var(--shadow-hover);
        }

        .term-word {
            font-weight: 600;
            color: var(--primary-dark);
            font-size: 0.9rem;
        }

        .term-def {
            color: var(--text-secondary);
            font-size: 0.8rem;
            margin-top: 2px;
            line-height: 1.6;
        }

        /* ---- 应用场景卡片 ---- */
        .scene-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        .scene-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            text-align: center;
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
        }

        .scene-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: var(--border-accent);
        }

        .scene-icon {
            font-size: 2rem;
            margin-bottom: var(--space-sm);
        }

        .scene-card h3 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
        }

        .scene-desc {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.6;
        }

        /* ---- 公式块 ---- */
        .formula-box {
            background: hsl(var(--primary-hue) 40% 97%);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--space-sm) var(--space-md);
            margin-bottom: var(--space-md);
            font-size: 0.95rem;
            line-height: 2;
            overflow-x: auto;
            text-align: center;
        }
        .formula-box mjx-container {
            display: inline-block;
            vertical-align: middle;
        }
        .formula-box mjx-container[display="true"] {
            display: block;
            margin: var(--space-xs) 0;
        }
        .act-card .formula-box {
            background: transparent;
            border: none;
            padding: 0;
            margin: var(--space-xs) 0;
            font-size: 0.85rem;
            line-height: 1.8;
            text-align: left;
        }

        .formula-desc {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.65;
            margin-top: var(--space-xs);
            font-family: 'Noto Sans SC', sans-serif;
        }

        /* ---- 算法分类大卡片 ---- */
        .algo-section-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            margin-bottom: var(--space-md);
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
        }

        .algo-section-card:hover {
            border-color: var(--border-accent);
            box-shadow: var(--shadow-hover);
        }

        .algo-section-card h4 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.05rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
            display: flex;
            align-items: center;
            gap: var(--space-sm);
        }

        .algo-section-card p {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.65;
        }

        /* ---- 两栏布局 ---- */
        .two-col {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        @media (max-width: 768px) {
            .two-col {
                grid-template-columns: 1fr;
            }
            .flow-step:not(:last-child)::after {
                display: none;
            }
        }

        /* ---- 子主题列表 ---- */
        .topic-list {
            list-style: none;
            padding: 0;
        }

        .topic-list li {
            padding: var(--space-sm) var(--space-md);
            margin-bottom: var(--space-xs);
            background: var(--bg-elevated);
            border-radius: var(--radius-sm);
            border-left: 3px solid var(--accent);
            color: var(--text-secondary);
            font-size: 0.85rem;
            transition: all var(--transition-base);
        }

        .topic-list li:hover {
            border-left-color: var(--primary);
            transform: translateX(4px);
        }

        .topic-list li strong {
            color: var(--text-primary);
        }

        /* ---- 训练阶段时间线 ---- */
        .stage-timeline {
            position: relative;
            padding-left: 2rem;
            margin-bottom: var(--space-lg);
        }

        .stage-timeline::before {
            content: '';
            position: absolute;
            left: 0.6rem;
            top: 0;
            bottom: 0;
            width: 2px;
            background: linear-gradient(to bottom, var(--primary), var(--accent));
        }

        .stage-item {
            position: relative;
            margin-bottom: var(--space-lg);
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
        }

        .stage-item:hover {
            border-color: var(--border-accent);
            box-shadow: var(--shadow-hover);
        }

        .stage-item::before {
            content: '';
            position: absolute;
            left: -1.7rem;
            top: 1.2rem;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background: var(--primary);
            border: 2px solid var(--bg-canvas);
        }

        .stage-item:nth-child(2)::before { background: #F59E0B; }
        .stage-item:nth-child(3)::before { background: #10B981; }
        .stage-item:nth-child(4)::before { background: #6366F1; }
        .stage-item:nth-child(5)::before { background: #8B5CF6; }

        .stage-item h4 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.05rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
        }

        .stage-item p {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.65;
        }

        .stage-badge {
            display: inline-block;
            font-size: 0.65rem;
            padding: 2px 10px;
            border-radius: var(--radius-xl);
            margin-left: var(--space-sm);
            vertical-align: middle;
        }

        /* ---- 推理流程可视化 ---- */
        .inference-flow {
            display: flex;
            flex-wrap: wrap;
            gap: var(--space-sm);
            justify-content: center;
            margin-bottom: var(--space-lg);
        }

        .inference-step {
            flex: 1;
            min-width: 140px;
            max-width: 180px;
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-md);
            text-align: center;
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
        }

        .inference-step:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
        }

        .inference-num {
            display: inline-block;
            width: 26px;
            height: 26px;
            line-height: 26px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--primary), var(--accent));
            color: #fff;
            font-size: 0.75rem;
            font-weight: 600;
            margin-bottom: var(--space-xs);
        }

        .inference-step h4 {
            font-size: 0.85rem;
            color: var(--text-primary);
            margin-bottom: var(--space-xs);
        }

        .inference-step p {
            font-size: 0.72rem;
            color: var(--text-secondary);
            line-height: 1.5;
        }

        /* ---- 注意力机制卡片 ---- */
        .attention-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        .attention-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            text-align: center;
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            border-top: 3px solid #6366F1;
        }

        .attention-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }

        .attention-card:nth-child(2) { border-top-color: #F59E0B; }
        .attention-card:nth-child(3) { border-top-color: #10B981; }
        .attention-card:nth-child(4) { border-top-color: #EC4899; }

        .attention-card h4 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
        }

        .attention-card p {
            color: var(--text-secondary);
            font-size: 0.83rem;
            line-height: 1.6;
        }

        .attention-card .mono {
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.8rem;
            color: var(--primary);
            background: hsl(var(--primary-hue) 60% 96%);
            padding: 2px 8px;
            border-radius: var(--radius-sm);
            display: inline-block;
            margin: var(--space-xs) 0;
        }

        /* ==========================================
           新增：可视化容器
           ========================================== */
        .viz-section {
            margin: var(--space-2xl) 0;
        }

        .viz-title {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.3rem;
            font-weight: 700;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
            text-align: center;
        }

        .viz-subtitle {
            color: var(--text-secondary);
            font-size: 0.95rem;
            line-height: 1.8;
            margin-bottom: var(--space-lg);
            text-align: center;
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }

        .viz-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-xl) var(--space-lg);
            margin-bottom: var(--space-2xl);
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            position: relative;
            overflow: hidden;
        }

        .viz-card:hover {
            border-color: var(--border-accent);
            box-shadow: var(--shadow-hover);
        }

        .viz-card h3 {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.15rem;
            color: var(--text-primary);
            margin-bottom: var(--space-sm);
            display: flex;
            align-items: center;
            gap: var(--space-sm);
        }

        .viz-card p {
            color: var(--text-secondary);
            font-size: 0.9rem;
            line-height: 1.7;
            margin-bottom: var(--space-md);
        }

        .viz-svg-container {
            background: linear-gradient(135deg, #FAFBFC, #F8FAFC);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            margin: var(--space-lg) 0;
            text-align: center;
            overflow: hidden;
        }

        .viz-svg-container svg {
            display: block;
            width: 100%;
            height: auto;
            max-width: 700px;
            margin: 0 auto;
        }

        .viz-caption {
            font-size: 0.8rem;
            color: var(--text-muted);
            text-align: center;
            margin-top: var(--space-sm);
            font-style: italic;
        }

        /* ==========================================
           Embedding 散点图动画
           ========================================== */
        .embedding-dot {
            transition: all 0.3s ease;
        }

        .embedding-dot:hover {
            r: 8 !important;
            filter: brightness(1.2);
        }

        @keyframes dotAppear {
            from { opacity: 0; transform: scale(0); }
            to { opacity: 1; transform: scale(1); }
        }

        .embedding-dot {
            animation: dotAppear 0.5s ease-out both;
        }

        @keyframes gridPulse {
            0%, 100% { opacity: 0.3; }
            50% { opacity: 0.6; }
        }

        .embedding-grid {
            animation: gridPulse 4s ease-in-out infinite;
        }

        /* ==========================================
           Transformer 前向传播动画
           ========================================== */
        .tf-block {
            transition: all 0.3s ease;
        }

        .tf-block:hover {
            filter: brightness(1.1);
        }

        @keyframes signalFlow {
            0% { opacity: 0; stroke-dashoffset: 200; }
            20% { opacity: 1; }
            80% { opacity: 1; }
            100% { opacity: 0; stroke-dashoffset: 0; }
        }

        .tf-signal {
            animation: signalFlow 3s ease-in-out infinite;
        }

        @keyframes blockPulse {
            0%, 100% { opacity: 0.7; }
            50% { opacity: 1; }
        }

        .tf-block-animated {
            animation: blockPulse 3s ease-in-out infinite;
        }

        /* ==========================================
           Attention 热力图动画
           ========================================== */
        .attention-cell {
            transition: all 0.3s ease;
        }

        .attention-cell:hover {
            stroke: var(--primary);
            stroke-width: 2;
        }

        @keyframes heatWave {
            0%, 100% { opacity: 0.7; }
            50% { opacity: 1; }
        }

        .attention-hot {
            animation: heatWave 2s ease-in-out infinite;
        }

        @keyframes tokenHighlight {
            0%, 100% { fill-opacity: 1; }
            50% { fill-opacity: 0.6; }
        }

        .token-highlight {
            animation: tokenHighlight 2s ease-in-out infinite;
        }

        /* ==========================================
           神经网络结构动画
           ========================================== */
        @keyframes signalPulse {
            0% { r: 2; opacity: 0; }
            20% { r: 5; opacity: 1; }
            80% { r: 5; opacity: 1; }
            100% { r: 2; opacity: 0; }
        }

        .nn-signal {
            animation: signalPulse 2s ease-in-out infinite;
        }

        .nn-node {
            transition: all 0.3s ease;
        }

        .nn-node:hover {
            filter: brightness(1.2);
        }

        @keyframes weightFlow {
            0% { stroke-dashoffset: 0; }
            100% { stroke-dashoffset: 20; }
        }

        .nn-weight-line {
            stroke-dasharray: 4, 4;
            animation: weightFlow 1s linear infinite;
        }

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

        .fade-in-up {
            animation: fadeInUp 0.6s ease-out both;
        }

        /* ==========================================
           新增：前向传播 & 反向传播动画
           ========================================== */
        @keyframes forwardSignal {
            0% { opacity: 0; stroke-dashoffset: 300; }
            15% { opacity: 1; }
            85% { opacity: 1; }
            100% { opacity: 0; stroke-dashoffset: 0; }
        }

        .forward-signal {
            animation: forwardSignal 2.5s ease-in-out infinite;
        }

        @keyframes backwardSignal {
            0% { opacity: 0; stroke-dashoffset: 300; }
            15% { opacity: 1; }
            85% { opacity: 1; }
            100% { opacity: 0; stroke-dashoffset: 0; }
        }

        .backward-signal {
            animation: backwardSignal 2.5s ease-in-out infinite reverse;
        }

        @keyframes nodeGlow {
            0%, 100% { r: 10; opacity: 0.8; }
            50% { r: 13; opacity: 1; }
        }

        .node-glow {
            animation: nodeGlow 2s ease-in-out infinite;
        }

        @keyframes lossDrop {
            0% { stroke-dashoffset: 600; }
            100% { stroke-dashoffset: 0; }
        }

        .loss-curve {
            animation: lossDrop 4s ease-out infinite;
        }

        @keyframes ballRoll {
            0% { transform: translate(80px, 30px); }
            30% { transform: translate(200px, 90px); }
            60% { transform: translate(320px, 50px); }
            100% { transform: translate(420px, 130px); }
        }

        .loss-ball {
            animation: ballRoll 4s ease-out infinite;
        }

        @keyframes convSlide {
            0%, 100% { opacity: 0.6; }
            50% { opacity: 1; }
        }

        .conv-kernel {
            animation: convSlide 1.5s ease-in-out infinite;
        }

        @keyframes gateOpen {
            0%, 100% { opacity: 0.5; }
            50% { opacity: 1; }
        }

        .gate-active {
            animation: gateOpen 2s ease-in-out infinite;
        }

        @keyframes ganLoop {
            0% { stroke-dashoffset: 80; }
            100% { stroke-dashoffset: 0; }
        }

        .gan-loop-line {
            stroke-dasharray: 6, 4;
            animation: ganLoop 1.5s linear infinite;
        }

        @keyframes qkvHighlight {
            0%, 100% { fill-opacity: 0.6; }
            50% { fill-opacity: 1; }
        }

        .qkv-highlight {
            animation: qkvHighlight 2s ease-in-out infinite;
        }

        @keyframes attnHeat {
            0%, 100% { opacity: 0.4; }
            50% { opacity: 0.9; }
        }

        .attn-heat {
            animation: attnHeat 1.5s ease-in-out infinite;
        }

        @keyframes residualPulse {
            0%, 100% { stroke-dashoffset: 0; }
            50% { stroke-dashoffset: 10; }
        }

        .residual-line {
            stroke-dasharray: 8, 4;
            animation: residualPulse 1s linear infinite;
        }

        @keyframes skipBounce {
            0%, 100% { transform: translateY(0); }
            50% { transform: translateY(-3px); }
        }

        .skip-bounce {
            animation: skipBounce 1.5s ease-in-out infinite;
        }

        /* ==========================================
            激活函数演进链
            ========================================== */
        .evo-note {
            background: linear-gradient(135deg, #EEF2FF, #F8FAFC);
            border: 1px solid #C7D2FE;
            border-radius: var(--radius-md);
            padding: var(--space-md) var(--space-lg);
            margin: var(--space-sm) 0 var(--space-lg);
            font-size: 0.85rem;
            color: var(--text-secondary);
            line-height: 1.7;
        }
        .evo-note strong {
            color: var(--text-primary);
        }

        .act-evo-chain {
            display: flex;
            align-items: stretch;
            justify-content: space-between;
            gap: 6px;
            margin-bottom: var(--space-lg);
            padding: var(--space-lg) var(--space-md);
            background: var(--bg-elevated);
            border-radius: var(--radius-lg);
            border: 1px solid var(--border-subtle);
        }

        .act-evo-item {
            flex: 1;
            min-width: 0;
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--space-sm) var(--space-md);
            transition: all var(--transition-base);
            position: relative;
            border-top: 3px solid var(--evo-color, #6366F1);
        }
        .act-evo-item:hover {
            transform: translateY(-3px);
            box-shadow: var(--shadow-hover);
            border-color: var(--evo-color, #6366F1);
        }

        .act-evo-step {
            font-size: 0.88rem;
            font-weight: 700;
            color: var(--evo-color, #6366F1);
            margin-bottom: 1px;
        }
        .act-evo-era {
            font-size: 0.65rem;
            font-family: 'JetBrains Mono', monospace;
            color: var(--text-muted);
            margin-bottom: 4px;
        }
        .act-evo-pros {
            font-size: 0.72rem;
            color: var(--text-secondary);
            line-height: 1.4;
            margin-bottom: 1px;
        }
        .act-evo-cons {
            font-size: 0.7rem;
            color: var(--text-muted);
            line-height: 1.4;
        }

        .act-evo-arrow {
            display: flex;
            align-items: center;
            font-size: 1.3rem;
            color: var(--text-muted);
            flex-shrink: 0;
            font-weight: 300;
        }

        @media (max-width: 768px) {
            .act-evo-chain {
                flex-direction: column;
                gap: 8px;
            }
            .act-evo-arrow {
                transform: rotate(90deg);
                justify-content: center;
                padding: 2px 0;
            }
        }

        /* ==========================================
            激活函数卡片
            ========================================== */
        .act-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: var(--space-lg);
            margin-bottom: var(--space-lg);
        }

        .act-card {
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-lg);
            padding: var(--space-lg);
            transition: all var(--transition-slow);
            box-shadow: var(--shadow-sm);
            position: relative;
            overflow: hidden;
        }

        .act-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            opacity: 0;
            transition: opacity var(--transition-base);
        }

        .act-card:hover::before { opacity: 1; }

        .act-card:nth-child(1)::before { background: linear-gradient(90deg, #EC4899, #F472B6); }
        .act-card:nth-child(2)::before { background: linear-gradient(90deg, #F59E0B, #FBBF24); }
        .act-card:nth-child(3)::before { background: linear-gradient(90deg, #10B981, #34D399); }
        .act-card:nth-child(4)::before { background: linear-gradient(90deg, #8B5CF6, #A78BFA); }
        .act-card:nth-child(5)::before { background: linear-gradient(90deg, #6366F1, #818CF8); }
        .act-card:nth-child(6)::before { background: linear-gradient(90deg, #EF4444, #F87171); }

        .act-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
        }
        .act-card:nth-child(1):hover { border-color: rgba(236,72,153,0.3); }
        .act-card:nth-child(2):hover { border-color: rgba(245,158,11,0.3); }
        .act-card:nth-child(3):hover { border-color: rgba(16,185,129,0.3); }
        .act-card:nth-child(4):hover { border-color: rgba(139,92,246,0.3); }
        .act-card:nth-child(5):hover { border-color: rgba(99,102,241,0.3); }
        .act-card:nth-child(6):hover { border-color: rgba(239,68,68,0.3); }

        .act-card h3 {
            font-size: 0.9rem;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            border-left: none;
            padding-left: 0;
            margin: 0 0 var(--space-xs);
        }

        .act-name {
            font-family: 'Noto Serif SC', serif;
            font-size: 1.1rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 2px;
        }

        .act-en {
            font-size: 0.7rem;
            color: var(--text-muted);
            letter-spacing: 0.05em;
            margin-bottom: var(--space-sm);
        }

        .act-formula {
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.8rem;
            color: var(--primary);
            background: hsl(var(--primary-hue) 60% 96%);
            padding: 3px 10px;
            border-radius: var(--radius-sm);
            display: inline-block;
            margin-bottom: var(--space-sm);
        }

        .act-graph {
            background: linear-gradient(135deg, #FAFBFC, #F8FAFC);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            padding: var(--space-sm);
            margin-bottom: var(--space-sm);
        }

        .act-graph svg {
            display: block;
            width: 100%;
            height: auto;
        }

        .act-section-title {
            font-family: 'Noto Sans SC', sans-serif;
            font-size: 0.72rem;
            font-weight: 600;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            margin-top: var(--space-sm);
            margin-bottom: 2px;
        }

        .act-section-text {
            font-size: 0.82rem;
            color: var(--text-secondary);
            line-height: 1.6;
            margin-bottom: var(--space-xs);
        }

        .act-highlight {
            color: var(--primary);
            font-weight: 600;
        }

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

        /* ==========================================
           实战速查表 — 激活函数选择卡片
           ========================================== */

        .act-cheat-grid {
            display: flex;
            flex-direction: column;
            gap: var(--space-sm);
            margin-top: var(--space-lg);
        }

        .act-cheat-item {
            display: grid;
            grid-template-columns: 60px 1fr 1.2fr 1.5fr;
            gap: var(--space-md);
            align-items: center;
            padding: var(--space-md) var(--space-lg);
            background: var(--bg-card);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-md);
            transition: all var(--transition-base);
        }

        .act-cheat-item:hover {
            transform: translateX(5px);
            box-shadow: var(--shadow-hover);
            border-color: var(--border-accent);
        }

        .act-cheat-rank {
            font-size: 0.72rem;
            font-weight: 700;
            letter-spacing: 0.05em;
            color: var(--text-muted);
            white-space: nowrap;
        }

        .act-cheat-name {
            font-family: 'JetBrains Mono', monospace;
            font-size: 0.9rem;
            font-weight: 600;
            color: var(--text-primary);
        }

        .act-cheat-scene {
            font-size: 0.8rem;
            color: var(--text-secondary);
            line-height: 1.4;
        }

        .act-cheat-note {
            font-size: 0.78rem;
            color: var(--text-muted);
            line-height: 1.5;
        }

        @media (max-width: 768px) {
            .act-cheat-item {
                grid-template-columns: 1fr;
                gap: 4px;
            }
            .act-cheat-rank {
                font-size: 0.65rem;
            }
        }