/* ========== 基础样式 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #1f6feb;
    --primary-dark: #1a5fc7;
    --secondary-color: #07c160;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-muted: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ========== 导航栏 ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    padding: 16px 0;
}

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

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

.nav-brand .logo {
    width: 32px;
    height: 32px;
    object-fit: contain;
}

.brand-text {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 15px;
    transition: color 0.2s;
}

.nav-link:hover {
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s;
}

/* ========== Hero 区域 ========== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0.05;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 60px 0;
    width: 100%;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.gradient-text {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-actions {
    margin-bottom: 60px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    color: var(--text-muted);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* ========== Section 通用 ========== */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
}

/* ========== 核心洞察横幅 ========== */
.insight-banner {
    background: linear-gradient(135deg, #f3e5f5 0%, #e3f2fd 100%);
    padding: 40px 0;
    text-align: center;
}

.insight-text {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ========== 三层价值链 ========== */
.value-chain {
    background: var(--bg-secondary);
    padding: 80px 0;
}

.chain-layers {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.chain-layer {
    background: white;
    border-radius: var(--radius-md);
    padding: 32px;
    box-shadow: var(--shadow-md);
    position: relative;
    transition: transform 0.3s ease;
}

.chain-layer:hover {
    transform: translateY(-4px);
}

.layer-tag {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.chain-layer h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.chain-layer p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
}

.layer-tools {
    font-size: 13px;
    color: var(--primary-color);
    font-weight: 600;
    padding-top: 16px;
    border-top: 2px solid var(--bg-tertiary);
}

/* ========== 信任条 ========== */
.trust-bar {
    background: white;
    padding: 80px 0;
}

.trust-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 32px;
    margin-top: 40px;
}

.trust-item {
    text-align: center;
    padding: 24px;
}

.trust-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.trust-item h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.trust-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

@media (max-width: 768px) {
    .insight-text {
        font-size: 18px;
    }
    
    .chain-layers {
        grid-template-columns: 1fr;
    }
    
    .trust-items {
        grid-template-columns: 1fr;
    }
}

/* ========== 复习闭环 ========== */
.review-loop {
    background: var(--bg-primary);
    padding: 60px 0;
}

.loop-steps {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    gap: 20px;
    margin-top: 40px;
}

.loop-step {
    flex: 1;
    max-width: 280px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 30px 24px;
    position: relative;
    border: 1px solid var(--border-color);
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    margin-bottom: 16px;
}

.step-content h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.step-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.loop-arrow {
    font-size: 28px;
    color: var(--primary-color);
    font-weight: 700;
    margin-top: 60px;
}

.loop-cta {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
    border-radius: var(--radius-md);
}

.loop-cta p {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

@media (max-width: 768px) {
    .loop-steps {
        flex-direction: column;
        align-items: center;
    }
    
    .loop-step {
        max-width: 100%;
        width: 100%;
    }
    
    .loop-arrow {
        margin-top: 0;
        transform: rotate(90deg);
        margin: 10px 0;
    }
}

/* ========== 使用场景 ========== */
.scenes {
    background: var(--bg-secondary);
}

.scenes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.scene-card {
  background: white;
  border-radius: 12px;
  padding: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
  color: inherit;
  display: block;
}

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

.scene-icon {
    width: 48px;
    height: 48px;
    object-fit: contain;
    margin-bottom: 20px;
}

.scene-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.scene-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.scene-tool {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.tool-tag {
    font-size: 13px;
    color: var(--primary-color);
    background: rgba(31, 111, 235, 0.1);
    padding: 4px 12px;
    border-radius: 999px;
}

.tool-price {
    font-size: 13px;
    color: var(--text-muted);
}

/* ========== 工具介绍 ========== */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.tool-card {
    display: flex;
    gap: 20px;
    background: white;
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
    text-decoration: none;
    color: inherit;
}

.tool-card:hover {
    box-shadow: var(--shadow-md);
}

.tool-icon {
    width: 40px;
    height: 40px;
    object-fit: contain;
    flex-shrink: 0;
}

.tool-info h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.tool-info p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 12px;
}

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

.price {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
}

.price.free {
    color: var(--secondary-color);
}

.tool-meta .desc {
    font-size: 13px;
    color: var(--text-muted);
}

.tools-notice {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 15px;
}

/* ========== 使用教程 ========== */
.tutorials {
    background: var(--bg-secondary);
}

.tutorials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.tutorial-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 32px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
}

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

.tutorial-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.tutorial-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.tutorial-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 20px;
}

.tutorial-link {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
}

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

/* ========== 常见问题 ========== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    border-radius: var(--radius-md);
    margin-bottom: 12px;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.faq-item summary {
    padding: 20px 24px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    font-size: 24px;
    color: var(--text-muted);
    transition: transform 0.2s;
}

.faq-item[open] summary::after {
    transform: rotate(45deg);
}

.faq-item p {
    padding: 0 24px 20px;
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========== 联系反馈 ========== */
.contact {
    background: var(--bg-secondary);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info {
    text-align: left;
}

.contact-desc {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 16px;
}

.method-icon {
    font-size: 32px;
}

.contact-method h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

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

/* 联系表单 */
.contact-form {
    background: white;
    padding: 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.contact-form h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 24px;
    color: var(--text-primary);
}

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

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.contact-form .btn {
    width: 100%;
    justify-content: center;
}

/* ========== 页脚 ========== */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: start;
    margin-bottom: 40px;
}

.footer-brand {
    text-align: left;
}

.footer-brand .logo {
    width: 40px;
    height: 40px;
    object-fit: contain;
    margin-bottom: 8px;
}

.footer-brand .brand-text {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.footer-brand p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    margin-top: 4px;
}

.footer-note {
    font-size: 12px !important;
    color: rgba(255, 255, 255, 0.5) !important;
}

.footer-qrcodes {
    display: flex;
    gap: 20px;
}

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

.footer-qrcode img {
    width: 80px;
    height: 80px;
    border-radius: 8px;
    background: white;
    padding: 4px;
}

.footer-qrcode p {
    font-size: 14px !important;
    color: rgba(255, 255, 255, 0.7) !important;
    margin: 0 !important;
}

.footer-links {
    display: flex;
    gap: 60px;
    justify-content: flex-end;
}

.link-group h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 16px;
}

.link-group a {
    display: block;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    margin-bottom: 8px;
    transition: color 0.2s;
}

.link-group a:hover {
    color: white;
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}

.footer-bottom p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
    margin: 0;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: white;
}

/* ========== 弹窗 ========== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: white;
    border-radius: var(--radius-lg);
    padding: 32px;
    text-align: center;
    max-width: 320px;
    width: 90%;
    position: relative;
}

.modal-close {
    position: absolute;
    top: 12px;
    right: 12px;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-muted);
}

.modal-content h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.qrcode-image img {
    width: 200px;
    height: 200px;
    border-radius: 8px;
}

.modal-content p {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 16px;
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        pointer-events: all;
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }

    .section-title {
        font-size: 28px;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
        text-align: center;
    }

    .footer-brand {
        text-align: center;
    }

    .footer-links {
        justify-content: center;
        gap: 40px;
    }

    .footer-qrcodes {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }

    .footer-qrcode {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }

    .footer-qrcode p {
        white-space: nowrap;
    }

    .footer-qrcodes {
        justify-content: center;
    }
}