/* css/style.css */
:root {
    --primary: #FF6D1D;
    --primary-light: #ff8a47;
    --dark-main: #26303D; /* 新增全局深色基调 */
    --bg-color: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --text-main: var(--dark-main); /* 文本全面接管为品牌深色 */
    --text-muted: #86868B;
    --font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --radius-lg: 24px;
    --radius-md: 16px;
    --shadow-soft: 0 10px 40px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 20px 50px rgba(0, 0, 0, 0.12);
    --transition-smooth: all 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ================= 导航栏 & 移动端遮罩 ================= */
.mobile-overlay {
    position: fixed; inset: 0; background: rgba(0,0,0,0.6);
    z-index: 998; opacity: 0; visibility: hidden; transition: 0.3s ease;
}
.mobile-overlay.active { opacity: 1; visibility: visible; }

nav {
    position: fixed; top: 0; left: 0; right: 0; height: 72px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 5%; z-index: 1000; border-bottom: 1px solid rgba(0,0,0,0.05);
}

.logo { display: flex; align-items: center; z-index: 1001; }
.logo img { height: 40px; object-fit: contain; }

.nav-links { display: flex; align-items: center; }
.links-desktop { display: flex; align-items: center; margin-right: 24px; }

.nav-item {
    text-decoration: none; color: var(--text-main); font-size: 15px;
    margin: 0 16px; font-weight: 500;
    position: relative; padding: 8px 0; transition: color 0.3s ease;
}
.nav-item::after {
    content: ''; position: absolute; bottom: 0; left: 50%;
    transform: translateX(-50%); width: 0; height: 2px; border-radius: 2px;
    background: var(--primary); transition: width 0.3s ease;
}
.nav-item:hover { color: var(--primary); }
.nav-item:hover::after, .nav-item.active::after { width: 100%; }

.mobile-menu-btn { display: none; font-size: 24px; cursor: pointer; color: var(--text-main); z-index: 1001; }

.btn-primary {
    background: var(--primary); color: #fff; padding: 12px 28px;
    border-radius: 99px; font-size: 15px; font-weight: 500;
    text-decoration: none; display: inline-block; transition: all 0.3s;
}
.btn-primary:hover {
    transform: scale(1.02); box-shadow: 0 8px 20px rgba(255, 109, 29, 0.3); color: #fff;
}

/* ================= 二维码组件 ================= */
.contact-wrapper { position: relative; display: inline-flex; justify-content: center; align-items: center;}
.qr-popup {
    position: absolute; width: 160px; background: #fff;
    border-radius: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    padding: 16px; text-align: center; opacity: 0; visibility: hidden;
    transition: all 0.3s ease; z-index: 100;
}
.qr-popup img { width: 100%; height: auto; border-radius: 8px; margin-bottom: 8px; display: block; }
.qr-popup p { font-size: 12px; color: var(--text-muted); line-height: 1.4; margin: 0; }

.popup-down { top: calc(100% + 15px); transform: translateY(-10px); }
.popup-up { bottom: calc(100% + 15px); transform: translateY(10px); }

/* 桌面端由 Hover 触发 */
@media (min-width: 769px) {
    .contact-wrapper:hover .popup-down,
    .contact-wrapper:hover .popup-up { opacity: 1; visibility: visible; transform: translateY(0); }
}
/* 移动端由 JS 点击添加类名触发 */
.contact-wrapper.show-qr .popup-down,
.contact-wrapper.show-qr .popup-up { opacity: 1; visibility: visible; transform: translateY(0); }

/* ================= 滚动渐显 ================= */
.reveal { opacity: 0; transform: translateY(40px); transition: var(--transition-smooth); }
.reveal.active { opacity: 1; transform: translateY(0); }

/* ================= 英雄区 ================= */
.hero {
    padding: 240px 5% 160px; text-align: center;
    background: radial-gradient(circle at 50% -20%, rgba(255,109,29,0.08) 0%, rgba(255,255,255,0) 60%);
}
.hero-title { font-size: 72px; font-weight: 800; letter-spacing: -2px; line-height: 1.25; margin-bottom: 32px; color: var(--dark-main); }
.cursor { display: inline-block; font-weight: 300; margin-left: 2px; animation: blink 1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }
.hero-subtitle { font-size: 21px; color: var(--text-muted); max-width: 800px; margin: 0 auto 48px; }

/* 极简箭头按钮设计 */
.hero-btn {
    display: inline-flex; align-items: center;
    background: transparent; color: var(--dark-main);
    font-size: 20px; font-weight: 600; text-decoration: none;
    padding: 10px 0; transition: color 0.3s ease;
}
.hero-btn i {
    margin-left: 8px; transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}
.hero-btn:hover { color: var(--primary); }
.hero-btn:hover i { transform: rotate(90deg); }

/* 苹果风文字扫光动画 (AI效能) */
.ai-sweep {
    background: linear-gradient(to right, var(--dark-main) 0%, var(--dark-main) 40%, var(--primary) 50%, var(--dark-main) 60%, var(--dark-main) 100%);
    background-size: 300% 100%;
    background-position: 100% 0; /* 初始停留在深色区域 */
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}
.ai-sweep.start-anim {
    animation: sweepLight 1.5s cubic-bezier(0.25, 1, 0.5, 1) forwards;
}
@keyframes sweepLight {
    0% { background-position: 100% 0; }
    100% { background-position: 0% 0; } /* 扫过橙色，最终停留在深色区域 */
}

/* ================= 核心杠杆区 (叠加视差设计) ================= */
.core-section {
    position: relative; z-index: 1;
    background: var(--bg-color); /* 防止透底 */
    padding: 0 5% 120px;
}
.core-content {
    /* 包裹层：用于接收 JS 传入的滚动 translateY，实现物理减速下沉 */
    will-change: transform;
}

.section-title { text-align: center; font-size: 36px; font-weight: 700; margin-bottom: 64px; letter-spacing: -1px; }
.levers-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; max-width: 1200px; margin: 0 auto; }

.lever-card {
    position: relative; border-radius: var(--radius-lg); padding: 48px 32px; background: #fff;
    box-shadow: var(--shadow-soft); overflow: hidden; z-index: 1; transition: box-shadow 0.4s ease;
}
.lever-card:hover { box-shadow: var(--shadow-hover); }

/* 流光背景底：从顶部 0deg 开始 */
.lever-card::before {
    content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
    background: conic-gradient(from 0deg at 50% 50%, transparent 70%, var(--primary) 100%);
    opacity: 0; z-index: -2;
}
.lever-card:hover::before { animation: rotateFlow 0.8s ease-out forwards; }
@keyframes rotateFlow {
    0% { transform: rotate(0deg); opacity: 1; }
    50% { opacity: 1; }
    100% { transform: rotate(240deg); opacity: 0; }
}
.lever-card::after {
    content: ''; position: absolute; inset: 2px; background: #fff;
    border-radius: calc(var(--radius-lg) - 2px); z-index: -1;
}
.lever-icon {
    width: 56px; height: 56px; background: rgba(255, 109, 29, 0.1); color: var(--primary);
    border-radius: 16px; display: flex; align-items: center; justify-content: center;
    font-size: 24px; margin-bottom: 24px;
}
.lever-card > * { position: relative; z-index: 2; }
.lever-card h3 { font-size: 22px; margin-bottom: 16px; }
.lever-card p { color: var(--text-muted); font-size: 15px; }

/* ================= 课程系统内容 (覆盖核心层) ================= */
.feature-section {
    position: relative; z-index: 2; /* 高于核心层 */
    padding: 120px 5%; 
    background: var(--bg-secondary);
    box-shadow: 0 -20px 50px rgba(0,0,0,0.03); /* 顶部的柔和阴影带来悬浮覆盖感 */
}
.feature-row { display: flex; align-items: center; gap: 8%; max-width: 1200px; margin: 0 auto 120px; }
.feature-row:last-child { margin-bottom: 0; }
.feature-row:nth-child(even) { flex-direction: row-reverse; }
.feature-content { flex: 1; }
.feature-content h2 { font-size: 36px; margin-bottom: 24px; line-height: 1.3;}
.feature-content p { font-size: 17px; color: var(--text-muted); margin-bottom: 32px; }
.feature-list li { list-style: none; margin-bottom: 16px; font-size: 16px; display: flex; align-items: flex-start; }
.feature-list li::before {
    content: '✓'; color: #fff; background: var(--primary); min-width: 20px; height: 20px; border-radius: 50%;
    display: inline-flex; justify-content: center; align-items: center; font-size: 12px; margin-right: 12px; margin-top: 4px;
}
.feature-visual { flex: 1; width: 100%; }
.media-mask {
    width: 100%; aspect-ratio: 4 / 3; background: #fff; border-radius: var(--radius-lg); box-shadow: var(--shadow-soft);
    position: relative; overflow: hidden; border: 1px solid rgba(0,0,0,0.03); display: flex; align-items: center; justify-content: center;
}
.media-mask img, .media-mask video { position: absolute; top: 0; left: 0; width: 100%; height: 100%; object-fit: cover; z-index: 2; background: #fff; }
.mock-ui { width: 80%; height: 75%; background: var(--bg-secondary); border-radius: 12px; padding: 24px; display: flex; flex-direction: column; gap: 16px; z-index: 1; }
.mock-line { height: 16px; background: rgba(0,0,0,0.05); border-radius: 8px;}
.mock-line.orange { background: rgba(255, 109, 29, 0.2); width: 60%; }

/* ================= 成果展示 ================= */
.outcomes { padding: 120px 5%; background: var(--bg-color); }
.outcomes-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; max-width: 1200px; margin: 0 auto; }
.outcome-card { 
    background: var(--bg-secondary); padding: 40px 20px; border-radius: var(--radius-lg); 
    display: flex; flex-direction: column; align-items: center; justify-content: center;
}
.outcome-card .number { 
    font-size: 48px; font-weight: 700; color: var(--primary); margin-bottom: 8px;
    font-variant-numeric: tabular-nums; white-space: nowrap;
}
.outcome-card .desc { font-size: 16px; font-weight: 500; text-align: center; }

/* ================= 适合谁加入 ================= */
.audience { padding: 120px 5%; background: var(--dark-main); color: #fff; text-align: center; }
.audience-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 1000px; margin: 48px auto 0; text-align: left; }
.audience-item { background: rgba(255,255,255,0.05); padding: 32px; border-radius: var(--radius-md); border: 1px solid rgba(255,255,255,0.1); }
.audience-item h4 { font-size: 18px; color: #fff; font-weight: 500; margin-bottom: 8px;}
.audience-item p { color: #aaa; font-size: 14px;}
.audience-item.full-width { grid-column: 1 / -1; text-align: center; }

/* ================= 页脚 ================= */
footer { padding: 48px 5%; background: #1a222c; border-top: 1px solid rgba(255,255,255,0.05);}
.footer-content {
    max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center;
}
.footer-brand img { height: 32px; filter: grayscale(100%) brightness(200%); opacity: 0.8; object-fit: contain;}
.footer-right { display: flex; align-items: center; gap: 40px; }
.copyright-text { color: #666; font-size: 12px; }
.footer-link { color: #aaa; text-decoration: none; font-size: 15px; transition: color 0.3s; cursor: pointer; }
.footer-link:hover { color: var(--primary); }

.mobile-break { display: none; }

/* =========================================
   响应式布局与媒体查询严格阻断
========================================= */
@media (max-width: 992px) {
    .feature-row, .feature-row:nth-child(even) { flex-direction: column; gap: 40px; }
    .levers-grid { grid-template-columns: 1fr; }
    .outcomes-grid { grid-template-columns: repeat(2, 1fr); }
    .audience-grid { grid-template-columns: 1fr; }
    .hero-title { font-size: 56px; }
}

@media (max-width: 768px) {
    .mobile-menu-btn { display: block; }
    
    .nav-links {
        position: absolute; top: 72px; left: 0; right: 0; background: #fff; 
        flex-direction: column; padding: 20px 5%; box-shadow: 0 10px 20px rgba(0,0,0,0.1);
        clip-path: inset(0 0 100% 0); opacity: 0; visibility: hidden; z-index: 999;
        transition: opacity 0.3s ease, clip-path 0.3s ease, visibility 0.3s ease;
    }
    nav.mobile-menu-open .nav-links { clip-path: inset(0 0 0 0); opacity: 1; visibility: visible; }
    
    .links-desktop { flex-direction: column; width: 100%; align-items: flex-start; margin: 0 0 20px 0; }
    .nav-item { margin: 0; width: 100%; border-bottom: 1px solid #eee; padding: 16px 0;}
    .nav-item::after { display: none; } 
    .contact-wrapper { width: 100%; display: flex; justify-content: center; }

    nav .popup-down { top: auto; bottom: calc(100% + 15px); transform: translateY(10px); right: auto;}
    nav .contact-wrapper.show-qr .popup-down { transform: translateY(0); }

    .logo img { height: 32px; }
    .hero { padding: 180px 5% 100px; }
    .hero-title { font-size: 40px; }
    .mobile-break { display: block; }
    .hero-subtitle { font-size: 16px; margin-bottom: 32px; }
    .section-title { font-size: 28px; margin-bottom: 40px; }
    .feature-content h2 { font-size: 28px; }
    
    .outcomes-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
    .outcome-card { padding: 24px 12px; }
    .outcome-card .number { font-size: 32px; margin-bottom: 4px; }
    .outcome-card .desc { font-size: 13px; }
    
    .footer-contact .qr-popup { right: 50%; margin-right: -80px; }
    .footer-content { flex-direction: column; gap: 32px; text-align: center; }
    .footer-right { flex-direction: column; gap: 16px; }
}