:root {
    --primary: #1296db;
    --primary-hover: #0e7cb8;
    --primary-active: #0b6799;
    --primary-light: #e3f2fd;
    --primary-dark: #0d47a1;
    --secondary: #0d47a1;
    --accent: #2196f3;
    --success: #4caf50;
    --warning: #ff9800;
    --info: #0288d1;
    --light: #f8f9fa;
    --dark: #212529;
    --border-radius: 12px;
    --box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    --transition: all 0.3s ease;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #444;
    background: linear-gradient(135deg, #f5f7ff 0%, #e6f0ff 100%);
    overflow-x: hidden;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 1.2rem 0;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.6rem;
    font-weight: 800;
}

.logo-img {
    width: 40px;
    height: 40px;
    background: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: var(--primary);
}

nav ul {
    display: flex;
    list-style: none;
    gap: 1.8rem;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 8px 12px;
    border-radius: 30px;
    transition: var(--transition);
    font-size: 1rem;
}

nav a:hover, nav a.active {
    background: rgba(255,255,255,0.2);
}

/* 英雄区域 */
.hero {
    background: linear-gradient(rgba(18, 150, 219, 0.9), rgba(13, 71, 161, 0.85)), 
        linear-gradient(135deg, var(--secondary), var(--primary));
    color: white;
    text-align: center;
    padding: 5rem 2rem;
    margin-bottom: 3rem;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, transparent 0%, rgba(0,0,0,0.3) 100%);
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3.2rem;
    margin-bottom: 1.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
    font-weight: 800;
}

.hero p {
    font-size: 1.3rem;
    margin: 0 auto 2.5rem;
    opacity: 0.95;
    line-height: 1.8;
}

.cta-button {
    display: inline-block;
    background: white;
    color: var(--primary);
    padding: 14px 32px;
    border-radius: 50px;
    font-weight: 700;
    text-decoration: none;
    font-size: 1.1rem;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    border: 2px solid transparent;
}

.cta-button:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.25);
    background: transparent;
    color: white;
    border-color: white;
}

/* 核心内容区域 */
.section {
    background: white;
    border-radius: var(--border-radius);
    padding: 3.5rem 3rem;
    margin-bottom: 3rem;
    box-shadow: var(--box-shadow);
    position: relative;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.section-title h2 {
    font-size: 2.5rem;
    color: var(--secondary);
    display: inline-block;
    padding-bottom: 15px;
    font-weight: 800;
}

.section-title h2:after {
    content: '';
    position: absolute;
    width: 80px;
    height: 4px;
    background: var(--accent);
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

.intro-text {
    font-size: 1.2rem;
    text-align: center;
    max-width: 900px;
    margin: 0 auto 3rem;
    line-height: 1.8;
    color: #555;
}

/* 知识体系结构 */
.knowledge-structure {
    display: flex;
    justify-content: space-between;
    margin-bottom: 4rem;
    gap: 25px;
}

.structure-item {
    flex: 1;
    text-align: center;
    padding: 2.2rem 1.5rem;
    border-radius: var(--border-radius);
    background: white;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary);
}

.structure-item:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.structure-icon {
    font-size: 3.2rem;
    margin-bottom: 1.5rem;
    color: var(--primary);
}

.structure-title {
    font-size: 1.7rem;
    margin-bottom: 1.2rem;
    color: var(--secondary);
    font-weight: 700;
}

.structure-desc {
    color: #666;
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

/* 教程卡片 */
.tutorial-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 2rem;
}

.card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    border-left: 4px solid var(--primary);
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.card-header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 1.6rem;
}

.card-header h3 {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.card-body {
    padding: 1.8rem;
}

.card-body ul {
    list-style: none;
    padding-left: 0;
}

.card-body li {
    padding: 12px 0;
    border-bottom: 1px solid #f0f0f0;
    display: flex;
    align-items: flex-start;
}

.card-body li:last-child {
    border-bottom: none;
}

.card-body li i {
    color: var(--accent);
    margin-right: 12px;
    margin-top: 5px;
    min-width: 20px;
}

.card-detail {
    background: #f9faff;
    border-left: 3px solid var(--accent);
    padding: 1.5rem;
    margin-top: 1rem;
    border-radius: 8px;
}

.card-detail h4 {
    color: var(--secondary);
    margin-bottom: 0.8rem;
    font-size: 1.2rem;
}

.card-detail ul {
    padding-left: 20px;
}

.card-detail li {
    margin-bottom: 8px;
    color: #555;
    border-bottom: none;
    padding: 5px 0;
    position: relative;
}

.card-detail li:before {
    content: "•";
    color: var(--accent);
    font-weight: bold;
    position: absolute;
    left: -20px;
}

/* 学习流程 */
.learning-steps {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0;
    margin-top: 3rem;
    position: relative;
}

/* 连接线 */
.learning-steps::before {
    content: '';
    position: absolute;
    top: 20px;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(to right, var(--primary), var(--success));
    z-index: -1;
    max-width: 90%;
    margin: 0 auto;
}

.step {
    flex: 1;
    min-width: 220px;
    max-width: 260px;
    background: white;
    border-radius: var(--border-radius);
    padding: 2.5rem 1.5rem 2rem;
    box-shadow: var(--box-shadow);
    position: relative;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-bottom: 4px solid var(--primary);
}

/* 为每个步骤添加不同的主题色 */
.step:nth-child(1) { border-color: var(--primary); }
.step:nth-child(2) { border-color: #90caf9; }
.step:nth-child(3) { border-color: var(--info); }
.step:nth-child(4) { border-color: var(--warning); }
.step:nth-child(5) { border-color: var(--success); }

.step:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.step-number {
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.5rem;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    z-index: 1;
}

/* 为每个步骤的数字添加不同的主题色 */
.step:nth-child(1) .step-number { background: var(--primary); }
.step:nth-child(2) .step-number { background: #90caf9; color: #0d47a1; }
.step:nth-child(3) .step-number { background: var(--info); }
.step:nth-child(4) .step-number { background: var(--warning); }
.step:nth-child(5) .step-number { background: var(--success); }

/* 增强数字的可见性 */
.step-number {
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.step h3 {
    color: var(--secondary);
    margin: 1rem 0 1rem;
    text-align: center;
    font-weight: 700;
    font-size: 1.3rem;
}

.step p {
    text-align: center;
    color: #555;
    line-height: 1.6;
    font-size: 0.95rem;
}

/* 响应式调整 */
@media (max-width: 1200px) {
    .learning-steps::before {
        display: none;
    }
    
    .learning-steps {
        flex-direction: column;
        align-items: center;
        gap: 40px;
    }
    
    .step {
        min-width: 300px;
        max-width: 500px;
    }
}

/* 工具卡片 */
.tools-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
    gap: 30px;
    margin-top: 2rem;
}

.tool-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    overflow: hidden;
    position: relative;
    background: linear-gradient(to bottom right, white 0%, #f9f9f9 100%);
}

/* 自我测评卡片样式 */
.tool-card.self-assessment {
    border-left: 4px solid var(--primary);
}

.tool-card.self-assessment .tool-icon {
    color: var(--primary);
}

.tool-card.self-assessment li:before {
    color: var(--primary);
}

/* AI助手卡片样式 */
.tool-card.ai-assistant {
    border-left: 4px solid var(--success);
}

.tool-card.ai-assistant .tool-icon {
    color: var(--success);
}

.tool-card.ai-assistant li:before {
    color: var(--success);
}

.tool-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.12);
}

/* 工具头部（图标和标题） */
.tool-header {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    gap: 1rem;
}

.tool-icon {
    font-size: 2.2rem;
    display: inline-block;
}

.tool-card h3 {
    font-size: 1.6rem;
    color: var(--secondary);
    margin: 0;
    font-weight: 700;
}

.tool-card p {
    text-align: center;
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.tool-card ul {
    padding-left: 0;
    margin-top: 1.5rem;
    list-style: none;
    text-align: center;
    max-width: 90%;
    margin-left: auto;
    margin-right: auto;
}

.tool-card li {
    margin-bottom: 12px;
    color: #555;
    position: relative;
    padding-left: 28px;
    line-height: 1.5;
    display: inline-block;
    text-align: left;
    width: 100%;
}

.tool-card li:before {
    content: "✓";
    font-weight: bold;
    position: absolute;
    left: 0;
    font-size: 1rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    background-color: rgba(18, 150, 219, 0.1);
    border-radius: 50%;
    top: 2px;
}

.tool-card.self-assessment li:before {
    background-color: rgba(18, 150, 219, 0.1);
}

.tool-card.ai-assistant li:before {
    background-color: rgba(76, 175, 80, 0.1);
}

/* 卡片底部装饰 */
.tool-card:after {
    content: '';
    position: absolute;
    bottom: -30px;
    right: -30px;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    opacity: 0.05;
    z-index: 0;
}

.tool-card.self-assessment:after {
    background-color: var(--primary);
}

.tool-card.ai-assistant:after {
    background-color: var(--success);
}

/* 确保内容在装饰层上方 */
.tool-card > * {
    position: relative;
    z-index: 1;
}

/* 二维码弹窗 */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: white;
    border-radius: var(--border-radius);
    padding: 2.5rem;
    text-align: center;
    max-width: 350px;
    box-shadow: 0 5px 30px rgba(0,0,0,0.3);
    position: relative;
    animation: modalIn 0.4s ease;
}

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

.close-modal {
    position: absolute;
    top: 15px;
    right: 15px;
    font-size: 1.8rem;
    cursor: pointer;
    color: #999;
    transition: var(--transition);
}

.close-modal:hover {
    color: var(--primary);
}

.qrcode {
    width: 200px;
    height: 200px;
    background: #f5f5f5;
    margin: 20px auto;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 8px;
    position: relative;
    overflow: hidden;
}

.qrcode:before {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background: 
        linear-gradient(135deg, transparent 0%, transparent 45%, #1296db 45%, #1296db 55%, transparent 55%, transparent 100%),
        linear-gradient(45deg, transparent 0%, transparent 45%, #0d47a1 45%, #0d47a1 55%, transparent 55%, transparent 100%);
    background-size: 20px 20px;
    opacity: 0.1;
}

.qrcode img {
    width: 180px;
    height: 180px;
    object-fit: contain;
}

.qrcode-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #666;
    font-size: 5rem;
}

.qrcode-placeholder i {
    font-size: 5rem;
    margin-bottom: 10px;
    color: var(--primary);
}

.modal-content h3 {
    color: var(--secondary);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.modal-content p {
    color: #666;
    margin-top: 15px;
    font-size: 0.9rem;
}

/* 页脚 */
footer {
    background: linear-gradient(135deg, #1a1a2e, #16213e);
    color: white;
    padding: 4rem 0 2rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 3rem;
}

.footer-column h3 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 12px;
    font-weight: 600;
}

.footer-column h3:after {
    content: '';
    position: absolute;
    width: 50px;
    height: 3px;
    background: var(--accent);
    bottom: 0;
    left: 0;
}

.footer-column ul {
    list-style: none;
}

.footer-column ul li {
    margin-bottom: 12px;
    display: flex;
    align-items: center;
}

.footer-column ul li i {
    margin-right: 10px;
    color: var(--accent);
    width: 20px;
}

.footer-column a {
    color: #ddd;
    text-decoration: none;
    transition: var(--transition);
    display: flex;
    align-items: center;
    cursor: pointer;
}

.footer-column a:hover {
    color: var(--accent);
    padding-left: 5px;
}

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: #aaa;
    font-size: 0.9rem;
}

.copyright a {
    color: #fff;
    text-decoration: none;
    padding: 2px 6px;
    border-radius: 4px;
    background-color: rgba(0,150,136,0.2);
    transition: all 0.3s ease;
}

.copyright a:hover {
    color: #fff;
    background-color: rgba(0,150,136,0.4);
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .knowledge-structure {
        flex-direction: column;
        gap: 30px;
    }
    
    .hero h1 {
        font-size: 2.6rem;
    }
    
    .tutorial-cards, .tools-container {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 12px;
    }
    
    .hero {
        padding: 4rem 1.5rem;
    }
    
    .hero h1 {
        font-size: 2.2rem;
    }
    
    .hero p {
        font-size: 1.1rem;
    }
    
    .section {
        padding: 2.5rem 1.8rem;
    }
    
    .section-title h2 {
        font-size: 2.2rem;
    }
    
    .learning-steps {
        gap: 40px;
    }
    
    .step {
        min-width: 100%;
    max-width: 100%;
    margin-bottom: 40px;
    position: relative;
    padding-top: 2rem;
    padding-bottom: 2rem;
    border-top: 4px solid var(--success);
    border-left: none;
    box-shadow: 0 8px 20px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    transform: none;
    min-height: 200px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: linear-gradient(145deg, #ffffff, #f0f0f0);
    }
    
    .step:hover {
        transform: scale(1.02);
        box-shadow: 0 12px 25px rgba(0,0,0,0.1);
    }
    
    .step-number {
        top: -25px;
        left: 50%;
        transform: translateX(-50%);
        width: 50px;
        height: 50px;
        font-size: 1.3rem;
        background: var(--success);
        box-shadow: 0 5px 15px rgba(76, 175, 80, 0.5);
        z-index: 10;
    }
    
    .step h3 {
        font-size: 1.5rem;
        margin-top: 15px;
        margin-bottom: 15px;
        color: var(--secondary);
        font-weight: 700;
        text-align: center;
    }
    
    .step p {
        font-size: 1.05rem;
        line-height: 1.6;
        color: #555;
        max-width: 90%;
        margin: 0 auto;
    }
    
    .tools-container {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        max-width: 90%;
        padding: 1.5rem;
    }
    
    .qrcode {
        width: 180px;
        height: 180px;
    }
}

/* 图标字体 */
.icon {
    display: inline-block;
    font-style: normal;
    font-weight: normal;
    line-height: 1;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.icon-tree:before { content: "🌳"; }
.icon-branch:before { content: "🌿"; }
.icon-seedling:before { content: "🌱"; }
.icon-handshake:before { content: "🤝"; }
.icon-briefcase:before { content: "💼"; }
.icon-heart:before { content: "❤️"; }
.icon-rocket:before { content: "🚀"; }
.icon-brain:before { content: "🧠"; }
.icon-comments:before { content: "💬"; }
.icon-user:before { content: "👤"; }
.icon-network:before { content: "🔗"; }
.icon-search:before { content: "🔍"; }
.icon-chart:before { content: "📈"; }
.icon-comment-dots:before { content: "💭"; }
.icon-clipboard:before { content: "📋"; }
.icon-robot:before { content: "🤖"; }
.icon-wechat:before { content: "💬"; }
.icon-tools:before { content: "🛠️"; }
.icon-check-circle:before { content: "✓"; font-weight: bold; color: var(--accent); }

/* 学习流程样式 */
.learning-flow-diagram {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    margin-top: 3rem;
    position: relative;
    padding: 2rem 0;
}

/* 连接线 - 桌面版 */
@media (min-width: 1200px) {
    .learning-flow-diagram::before {
        content: '';
        position: absolute;
        top: 50%;
        left: 5%;
        right: 5%;
        height: 6px;
        background: linear-gradient(to right, #1296db, #4caf50);
        z-index: -1;
        transform: translateY(-50%);
    }
}

/* 步骤卡片 */
.flow-step {
    flex: 1;
    min-width: 200px;
    max-width: 220px;
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem 1.5rem 1.5rem;
    box-shadow: var(--box-shadow);
    position: relative;
    text-align: center;
    transition: all 0.4s ease;
    border-top: 6px solid;
    margin: 0 15px;
    min-height: 340px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 每个步骤的主题色 */
.flow-step.step-1 { border-color: #1296db; }
.flow-step.step-2 { border-color: #0288d1; }
.flow-step.step-3 { border-color: #0d47a1; }
.flow-step.step-4 { border-color: #ff9800; }
.flow-step.step-5 { border-color: #4caf50; }

/* 步骤数字 */
.flow-step .step-number {
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.5rem;
    color: white;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    z-index: 1;
    transition: transform 0.3s ease;
}

/* 每个步骤的数字背景色 */
.flow-step.step-1 .step-number { background-color: #1296db; }
.flow-step.step-2 .step-number { background-color: #0288d1; }
.flow-step.step-3 .step-number { background-color: #0d47a1; }
.flow-step.step-4 .step-number { background-color: #ff9800; }
.flow-step.step-5 .step-number { background-color: #4caf50; }

/* 步骤图标 */
.step-icon {
    font-size: 2.5rem;
    margin: 1rem 0;
    transition: transform 0.3s ease;
}

.flow-step.step-1 .step-icon { color: #1296db; }
.flow-step.step-2 .step-icon { color: #0288d1; }
.flow-step.step-3 .step-icon { color: #0d47a1; }
.flow-step.step-4 .step-icon { color: #ff9800; }
.flow-step.step-5 .step-icon { color: #4caf50; }

/* 步骤标题 */
.flow-step h3 {
    color: var(--secondary);
    margin: 0.8rem 0;
    font-weight: 700;
    font-size: 1.3rem;
}

/* 步骤内容 */
.step-content {
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* 步骤描述 */
.step-description {
    color: #555;
    line-height: 1.6;
    font-size: 0.95rem;
    margin-bottom: 1rem;
    flex: 1;
}

/* 步骤提示 */
.step-tips {
    background-color: rgba(18, 150, 219, 0.05);
    border-radius: 8px;
    padding: 10px;
    font-size: 0.85rem;
    text-align: left;
}

.flow-step.step-1 .step-tips { background-color: rgba(18, 150, 219, 0.05); }
.flow-step.step-2 .step-tips { background-color: rgba(2, 136, 209, 0.05); }
.flow-step.step-3 .step-tips { background-color: rgba(13, 71, 161, 0.05); }
.flow-step.step-4 .step-tips { background-color: rgba(255, 152, 0, 0.05); }
.flow-step.step-5 .step-tips { background-color: rgba(76, 175, 80, 0.05); }

/* 步骤箭头 */
.step-arrow {
    position: absolute;
    right: -30px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 2rem;
    color: #ddd;
    font-weight: bold;
    transition: all 0.3s ease;
}

/* 悬停效果 */
.flow-step:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.flow-step:hover .step-number {
    transform: translateX(-50%) scale(1.1);
}

.flow-step:hover .step-icon {
    transform: scale(1.1);
}

.flow-step:hover .step-arrow {
    color: var(--primary);
    transform: translateY(-50%) translateX(5px);
}

/* 响应式调整 - 平板和手机 */
@media (max-width: 1200px) {
    .learning-flow-diagram {
        flex-direction: column;
        align-items: center;
    }
    
    .learning-flow-diagram::before {
        display: none;
    }
    
    .flow-step {
        width: 100%;
        max-width: 400px;
        margin: 30px 0;
        min-height: auto;
        position: relative;
    }
    
    /* 移动端连接线 */
    .flow-step:not(:last-child)::after {
        content: '';
        position: absolute;
        left: 50%;
        bottom: -30px;
        width: 4px;
        height: 30px;
        background: linear-gradient(to bottom, #1296db, #4caf50);
        transform: translateX(-50%);
    }
    
    .step-arrow {
        display: none;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 确保图标显示正常 */
.icon-book:before { content: "📚"; }
.icon-lightbulb:before { content: "💡"; }
.icon-chart-line:before { content: "📈"; }
.icon-refresh-cw:before { content: "🔄"; }