/* ============================================================
   企微智联 AI — 官网样式
   ============================================================ */

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --primary: #4F46E5;
    --primary-light: #6366F1;
    --primary-dark: #3730A3;
    --primary-bg: #EEF2FF;
    --accent: #06B6D4;
    --accent-light: #22D3EE;
    --text: #1E293B;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    --bg: #FFFFFF;
    --bg-alt: #F8FAFC;
    --bg-dark: #0F172A;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 4px 24px rgba(79,70,229,0.08);
    --shadow-lg: 0 12px 48px rgba(79,70,229,0.12);
    --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1200px;
    --nav-height: 72px;
}

html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 15px;
    font-weight: 600;
    padding: 12px 28px;
    border-radius: 50px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}
.btn-lg { padding: 16px 36px; font-size: 16px; }
.btn-primary {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(79,70,229,0.3);
}
.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}
.btn-outline:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-2px);
}

/* ---------- 标题区 ---------- */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}
.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--primary);
    background: var(--primary-bg);
    padding: 6px 18px;
    border-radius: 50px;
    margin-bottom: 16px;
}
.section-title {
    font-size: 36px;
    font-weight: 800;
    line-height: 1.25;
    color: var(--text);
    margin-bottom: 12px;
}
.section-desc {
    font-size: 17px;
    color: var(--text-secondary);
    max-width: 580px;
    margin: 0 auto;
}

/* ---------- 滚动入场动画 ---------- */
.fade-in-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================================
   导航
   ============================================================ */
.site-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--nav-height);
    z-index: 1000;
    background: rgba(255,255,255,0.85);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(79,70,229,0.06);
    transition: var(--transition);
}
.site-header.scrolled {
    box-shadow: 0 2px 20px rgba(0,0,0,0.06);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 800;
    color: var(--text);
}
.logo-icon {
    color: var(--primary);
    font-size: 26px;
}
.logo-text small {
    font-size: 14px;
    font-weight: 700;
    color: var(--primary-light);
    margin-left: 2px;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 32px;
}
.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
    position: relative;
}
.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px; left: 0;
    width: 0; height: 2px;
    background: var(--primary);
    border-radius: 2px;
    transition: var(--transition);
}
.nav-link:hover { color: var(--primary); }
.nav-link:hover::after { width: 100%; }

.btn-contact {
    padding: 10px 24px;
    font-size: 14px;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 28px;
    color: var(--text);
    cursor: pointer;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: calc(var(--nav-height) + 40px) 0 80px;
    overflow: hidden;
    background: linear-gradient(135deg, #f0f4ff 0%, #faf5ff 50%, #ecfeff 100%);
}
.hero-inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}
.hero-content { max-width: 600px; }
.hero-title {
    font-size: 52px;
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: 24px;
}
.gradient-text {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 36px;
}
.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}
.hero-stats {
    display: flex;
    gap: 40px;
}
.stat-item {
    text-align: center;
}
.stat-number {
    display: block;
    font-size: 32px;
    font-weight: 800;
    color: var(--primary);
    line-height: 1.2;
}
.stat-label {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 500;
}

/* Hero 插图 */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}
.hero-illustration {
    position: relative;
    width: 320px;
    height: 320px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.orbit-circle {
    position: absolute;
    border-radius: 50%;
    border: 2px solid rgba(79,70,229,0.15);
    animation: orbitSpin 12s linear infinite;
}
.orbit-1 {
    width: 320px; height: 320px;
    border-color: rgba(79,70,229,0.12);
}
.orbit-2 {
    width: 240px; height: 240px;
    border-color: rgba(6,182,212,0.15);
    animation-duration: 8s;
    animation-direction: reverse;
}
.orbit-3 {
    width: 160px; height: 160px;
    border-color: rgba(79,70,229,0.2);
    animation-duration: 6s;
}
.orbit-circle::before, .orbit-circle::after {
    content: '';
    position: absolute;
    width: 12px; height: 12px;
    border-radius: 50%;
    background: var(--primary-light);
    top: -6px; left: 50%;
    margin-left: -6px;
}
.orbit-2::before { background: var(--accent); }
.orbit-3::before { background: var(--primary); }
.orbit-circle::after {
    top: 50%; left: auto; right: -6px;
    margin-top: -6px; margin-left: 0;
}
.center-icon {
    width: 72px; height: 72px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #fff;
    font-size: 22px;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 32px rgba(79,70,229,0.3);
    z-index: 2;
}

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

/* Hero 背景装饰 */
.hero-bg-shapes { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
.shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.08;
}
.shape-1 {
    width: 600px; height: 600px;
    background: var(--primary);
    top: -200px; right: -100px;
}
.shape-2 {
    width: 400px; height: 400px;
    background: var(--accent);
    bottom: -100px; left: -100px;
}
.shape-3 {
    width: 200px; height: 200px;
    background: var(--primary);
    top: 40%; right: 30%;
}

/* ============================================================
   合作品牌
   ============================================================ */
.brands {
    padding: 40px 0;
    background: var(--bg);
    border-top: 1px solid rgba(0,0,0,0.04);
}
.brands-label {
    text-align: center;
    font-size: 13px;
    color: var(--text-muted);
    letter-spacing: 1px;
    margin-bottom: 24px;
}
.brands-list {
    display: flex;
    justify-content: center;
    gap: 48px;
    flex-wrap: wrap;
}
.brand-item {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 1px;
    opacity: 0.6;
    transition: var(--transition);
}
.brand-item:hover { opacity: 1; color: var(--primary); }

/* ============================================================
   痛点
   ============================================================ */
.pain-points {
    padding: 100px 0;
    background: var(--bg);
}
.pain-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.pain-card {
    background: var(--bg);
    border: 1px solid rgba(0,0,0,0.06);
    border-radius: var(--radius);
    padding: 32px 28px;
    transition: var(--transition);
    cursor: default;
}
.pain-card:hover {
    border-color: var(--primary-bg);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}
.pain-icon {
    font-size: 36px;
    margin-bottom: 16px;
}
.pain-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}
.pain-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   解决方案
   ============================================================ */
.solution-overview {
    padding: 100px 0;
    background: var(--bg-alt);
}
.solution-steps {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 32px;
}
.sol-step {
    display: flex;
    gap: 28px;
    background: var(--bg);
    border-radius: var(--radius);
    padding: 32px 36px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-left: 4px solid var(--primary);
}
.sol-step:hover {
    box-shadow: var(--shadow-lg);
    transform: translateX(6px);
}
.sol-num {
    flex-shrink: 0;
    font-size: 36px;
    font-weight: 900;
    color: var(--primary-bg);
    line-height: 1;
}
.sol-content h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
}
.sol-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   核心功能
   ============================================================ */
.features {
    padding: 100px 0;
    background: var(--bg);
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.feat-card {
    background: var(--bg);
    border: 1px solid rgba(0,0,0,0.06);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    transition: var(--transition);
    cursor: default;
}
.feat-card:hover {
    border-color: var(--primary-bg);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}
.feat-icon {
    width: 56px; height: 56px;
    border-radius: 16px;
    background: var(--primary-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 18px;
    font-size: 26px;
    transition: var(--transition);
}
.feat-card:hover .feat-icon {
    background: var(--primary);
}
.feat-card:hover .feat-icon span {
    filter: brightness(10);
}
.feat-card h3 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 10px;
}
.feat-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   应用场景
   ============================================================ */
.scenarios {
    padding: 100px 0;
    background: var(--bg-alt);
}
.scenario-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.scenario-card {
    border-radius: var(--radius);
    padding: 36px 28px;
    transition: var(--transition);
    cursor: default;
}
.scenario-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.scenario-icon {
    font-size: 36px;
    margin-bottom: 14px;
}
.scenario-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}
.scenario-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   为什么选择我们
   ============================================================ */
.why-us {
    padding: 100px 0;
    background: var(--bg);
}
.why-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.why-card {
    text-align: center;
    padding: 40px 24px;
    border-radius: var(--radius);
    border: 1px solid rgba(0,0,0,0.06);
    transition: var(--transition);
    cursor: default;
}
.why-card:hover {
    border-color: var(--primary-bg);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}
.why-number {
    font-size: 52px;
    font-weight: 900;
    color: var(--primary-bg);
    line-height: 1;
    margin-bottom: 16px;
}
.why-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 10px;
}
.why-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================================
   联系/咨询（无注册，仅咨询表单）
   ============================================================ */
.contact {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--bg-alt) 0%, var(--primary-bg) 100%);
}
.contact-inner {
    max-width: 660px;
    margin: 0 auto;
    text-align: center;
}
.contact-title {
    font-size: 34px;
    font-weight: 800;
    margin-bottom: 12px;
}
.contact-desc {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.7;
}
.contact-form {
    text-align: left;
}
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}
.form-row input,
.form-row textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: inherit;
    background: var(--bg);
    transition: var(--transition);
    outline: none;
}
.form-row input:focus,
.form-row textarea:focus {
    border-color: var(--primary-light);
    box-shadow: 0 0 0 4px rgba(79,70,229,0.1);
}
.form-row textarea {
    resize: vertical;
}
.btn-submit {
    width: 100%;
    margin-top: 8px;
}
.form-note {
    text-align: center;
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 12px;
}
.contact-alt {
    margin-top: 40px;
    padding-top: 32px;
    border-top: 1px solid rgba(0,0,0,0.06);
}
.contact-alt p {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 8px;
}
.contact-link {
    font-size: 18px;
    font-weight: 600;
    color: var(--primary);
    transition: var(--transition);
}
.contact-link:hover { color: var(--primary-dark); }

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.75);
    padding: 60px 0 0;
}
.footer-inner {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 40px;
}
.footer-brand .logo {
    color: #fff;
    margin-bottom: 16px;
}
.footer-brand .logo-icon { color: var(--accent); }
.footer-brand .logo-text small { color: var(--accent-light); }
.footer-desc {
    font-size: 14px;
    line-height: 1.7;
    color: rgba(255,255,255,0.55);
}
.footer-links h4,
.footer-contact h4 {
    font-size: 15px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 16px;
}
.footer-links a {
    display: block;
    font-size: 14px;
    color: rgba(255,255,255,0.55);
    margin-bottom: 10px;
    transition: var(--transition);
}
.footer-links a:hover { color: var(--accent-light); }
.footer-contact p {
    font-size: 14px;
    color: rgba(255,255,255,0.55);
    margin-bottom: 8px;
}
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.08);
    padding: 20px 0;
    text-align: center;
}
.footer-bottom p {
    font-size: 13px;
    color: rgba(255,255,255,0.35);
}

/* ============================================================
   响应式
   ============================================================ */

/* 平板 */
@media (max-width: 1024px) {
    .hero-title { font-size: 40px; }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .why-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 900px) {
    .hero-inner { grid-template-columns: 1fr; text-align: center; }
    .hero-content { max-width: 100%; }
    .hero-stats { justify-content: center; }
    .hero-actions { justify-content: center; }
    .hero-illustration { width: 240px; height: 240px; }
    .orbit-1 { width: 240px; height: 240px; }
    .orbit-2 { width: 180px; height: 180px; }
    .orbit-3 { width: 120px; height: 120px; }
    .hero-visual { display: none; }
    .pain-grid { grid-template-columns: repeat(2, 1fr); }
    .scenario-grid { grid-template-columns: repeat(2, 1fr); }
}

/* 手机 */
@media (max-width: 640px) {
    :root { --nav-height: 64px; }

    .main-nav {
        display: none;
        position: absolute;
        top: var(--nav-height); left: 0; right: 0;
        flex-direction: column;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(18px);
        padding: 16px 24px;
        gap: 16px;
        border-bottom: 1px solid rgba(0,0,0,0.06);
        box-shadow: 0 8px 24px rgba(0,0,0,0.06);
    }
    .main-nav.open { display: flex; }
    .btn-contact { display: none; }
    .menu-toggle { display: block; }

    .hero-title { font-size: 32px; }
    .hero-subtitle { font-size: 16px; }
    .hero-stats { gap: 24px; }
    .stat-number { font-size: 26px; }

    .section-title { font-size: 28px; }
    .section-desc { font-size: 15px; }

    .pain-grid { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }
    .scenario-grid { grid-template-columns: 1fr; }
    .why-grid { grid-template-columns: 1fr; }
    .footer-inner { grid-template-columns: 1fr; gap: 32px; }

    .form-row { grid-template-columns: 1fr; }

    .sol-step { flex-direction: column; gap: 12px; padding: 24px; }
    .sol-num { font-size: 28px; }

    .brands-list { gap: 24px; }
    .brand-item { font-size: 14px; }
}

/* ============================================================
   表单提交成功提示
   ============================================================ */
.form-success {
    text-align: center;
    padding: 40px 20px;
}
.form-success .success-icon {
    font-size: 56px;
    margin-bottom: 16px;
}
.form-success h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 8px;
}
.form-success p {
    color: var(--text-secondary);
}