/* ===================================
   广州智项云科技有限公司 - 主样式表
   =================================== */

/* ---- CSS Variables ---- */
:root {
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #818CF8;
    --secondary: #7C3AED;
    --accent: #06B6D4;
    --bg: #F8FAFC;
    --bg-white: #FFFFFF;
    --bg-dark: #0F172A;
    --bg-card: #FFFFFF;
    --text: #1E293B;
    --text-secondary: #64748B;
    --text-light: #94A3B8;
    --border: #E2E8F0;
    --success: #10B981;
    --gradient-1: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
    --gradient-2: linear-gradient(135deg, #06B6D4 0%, #3B82F6 100%);
    --gradient-dark: linear-gradient(135deg, #1E293B 0%, #0F172A 100%);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text);
    background-color: var(--bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ---- Container ---- */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---- Section ---- */
.section {
    padding: 100px 0;
}

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

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 2px;
    color: var(--primary);
    background: rgba(79, 70, 229, 0.08);
    border-radius: 50px;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 800;
    color: var(--text);
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ---- Header / Nav ---- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 12px 0;
    transition: var(--transition);
    background: transparent;
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
    padding: 8px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.02em;
}

.header:not(.scrolled) .logo-text {
    color: #fff;
}

.logo-icon {
    border-radius: 8px;
}

.header:not(.scrolled) .logo-icon {
    filter: brightness(1.2);
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text);
    position: relative;
    padding: 4px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-1);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.header:not(.scrolled) .nav-link {
    color: rgba(255, 255, 255, 0.9);
}

.header:not(.scrolled) .nav-link:hover,
.header:not(.scrolled) .nav-link.active {
    color: #fff;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

.header:not(.scrolled) .menu-toggle span {
    background: #fff;
}

/* ---- Hero ---- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: linear-gradient(160deg, #0F172A 0%, #1E293B 40%, #1E1B4B 70%, #0F172A 100%);
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-bg::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 80%;
    height: 200%;
    background: radial-gradient(ellipse at center, rgba(79, 70, 229, 0.15) 0%, transparent 70%);
    animation: bgPulse 8s ease-in-out infinite;
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 70%;
    height: 150%;
    background: radial-gradient(ellipse at center, rgba(6, 182, 212, 0.1) 0%, transparent 60%);
    animation: bgPulse 8s ease-in-out infinite reverse;
}

@keyframes bgPulse {
    0%, 100% { opacity: 0.6; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

.hero-particles {
    position: absolute;
    inset: 0;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 720px;
}

.hero-subtitle {
    font-size: 15px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.6);
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-bottom: 20px;
}

.hero-title {
    font-size: clamp(36px, 6vw, 64px);
    font-weight: 800;
    color: #fff;
    line-height: 1.15;
    margin-bottom: 24px;
    letter-spacing: -0.03em;
}

.gradient-text {
    background: linear-gradient(135deg, #818CF8, #C084FC, #60A5FA);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 580px;
}

.hero-btns {
    display: flex;
    gap: 16px;
    margin-bottom: 60px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
}

.btn-primary {
    background: var(--gradient-1);
    color: #fff;
    box-shadow: 0 4px 15px rgba(79, 70, 229, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(79, 70, 229, 0.5);
    color: #fff;
}

.btn-outline {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
    color: #fff;
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-number {
    font-size: 24px;
    font-weight: 700;
    color: #fff;
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
    letter-spacing: 1px;
}

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.scroll-indicator span {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 12px;
    position: relative;
}

.scroll-indicator span::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: rgba(255, 255, 255, 0.6);
    border-radius: 2px;
    animation: scrollDot 2s ease-in-out infinite;
}

@keyframes scrollDot {
    0%, 100% { top: 8px; opacity: 1; }
    50% { top: 20px; opacity: 0.3; }
}

/* ---- Animations ---- */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

.fade-in-up.delay-1 { animation-delay: 0.2s; }
.fade-in-up.delay-2 { animation-delay: 0.4s; }
.fade-in-up.delay-3 { animation-delay: 0.6s; }
.fade-in-up.delay-4 { animation-delay: 0.8s; }

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

/* ---- About ---- */
.about {
    background: var(--bg-white);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.about-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
}

.about-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.about-card:nth-child(3) {
    grid-column: 1 / -1;
}

.about-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(124, 58, 237, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: var(--primary);
}

.about-icon svg {
    width: 24px;
    height: 24px;
}

.about-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text);
}

.about-card p {
    color: var(--text-secondary);
    font-size: 15px;
    line-height: 1.8;
}

.badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 600;
}

.badge-green {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.text-muted {
    color: var(--text-light);
    font-size: 14px;
    margin-top: 8px;
}

.business-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 8px;
}

.business-tags span {
    display: inline-block;
    padding: 6px 14px;
    font-size: 13px;
    font-weight: 500;
    color: var(--primary);
    background: rgba(79, 70, 229, 0.06);
    border: 1px solid rgba(79, 70, 229, 0.12);
    border-radius: 50px;
    white-space: nowrap;
    transition: var(--transition);
}

.business-tags span:hover {
    background: rgba(79, 70, 229, 0.12);
    border-color: var(--primary-light);
}

/* ---- Services ---- */
.services {
    background: var(--bg);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-1);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.service-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-xl);
    transform: translateY(-4px);
}

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

.service-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.service-icon svg {
    width: 28px;
    height: 28px;
}

.service-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text);
}

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

.service-features {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.service-features li {
    font-size: 14px;
    color: var(--text-secondary);
    padding-left: 20px;
    position: relative;
}

.service-features li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    background: var(--primary);
    border-radius: 50%;
}

/* ---- AI Solutions ---- */
.ai-solutions {
    background: var(--bg-white);
}

.ai-tabs {
    max-width: 900px;
    margin: 0 auto;
}

.ai-tab-nav {
    display: flex;
    gap: 8px;
    margin-bottom: 40px;
    padding: 6px;
    background: var(--bg);
    border-radius: var(--radius-md);
    flex-wrap: wrap;
}

.ai-tab-btn {
    flex: 1;
    min-width: 140px;
    padding: 12px 20px;
    border: none;
    background: transparent;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.ai-tab-btn.active {
    background: var(--bg-white);
    color: var(--primary);
    box-shadow: var(--shadow-sm);
    font-weight: 600;
}

.ai-tab-btn:hover:not(.active) {
    color: var(--text);
    background: rgba(255, 255, 255, 0.5);
}

.ai-tab-content {
    display: none;
}

.ai-tab-content.active {
    display: block;
    animation: fadeInUp 0.5s ease;
}

.ai-highlight {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 48px;
    align-items: center;
    background: var(--bg);
    border-radius: var(--radius-xl);
    padding: 48px;
    border: 1px solid var(--border);
}

.ai-highlight-text h3 {
    font-size: 26px;
    font-weight: 800;
    margin-bottom: 16px;
    color: var(--text);
}

.ai-highlight-text p {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 20px;
}

.ai-highlight-text ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.ai-highlight-text ul li {
    font-size: 15px;
    color: var(--text);
    padding-left: 24px;
    position: relative;
}

.ai-highlight-text ul li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 6px;
    width: 8px;
    height: 8px;
    background: var(--gradient-1);
    border-radius: 2px;
    transform: rotate(45deg);
}

.ai-highlight-visual {
    display: flex;
    align-items: center;
    justify-content: center;
}

.ai-circle-anim {
    position: relative;
    width: 200px;
    height: 200px;
}

.ai-circle-outer {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    border: 2px solid rgba(79, 70, 229, 0.2);
    animation: circleRotate 10s linear infinite;
}

.ai-circle-mid {
    position: absolute;
    inset: 20px;
    border-radius: 50%;
    border: 2px dashed rgba(124, 58, 237, 0.3);
    animation: circleRotate 6s linear infinite reverse;
}

.ai-circle-inner {
    position: absolute;
    inset: 45px;
    border-radius: 50%;
    background: var(--gradient-1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 18px;
    box-shadow: 0 8px 32px rgba(79, 70, 229, 0.3);
}

@keyframes circleRotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ---- Contact ---- */
.contact {
    background: var(--bg);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 48px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.contact-card {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    transition: var(--transition);
}

.contact-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-md);
}

.contact-icon-wrap {
    width: 44px;
    height: 44px;
    min-width: 44px;
    border-radius: var(--radius-sm);
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(124, 58, 237, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.contact-icon-wrap svg {
    width: 22px;
    height: 22px;
}

.contact-card h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}

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

.contact-form-wrap {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 40px;
}

.contact-form-wrap h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 28px;
    color: var(--text);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
}

.form-group label span {
    color: var(--primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 13px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-family: inherit;
    color: var(--text);
    background: var(--bg);
    transition: var(--transition);
    outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
    background: var(--bg-white);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-full {
    width: 100%;
    justify-content: center;
    padding: 16px 32px;
    font-size: 16px;
}

.btn-icon {
    width: 20px;
    height: 20px;
}

.form-success {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px 24px;
    background: rgba(16, 185, 129, 0.08);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: var(--radius-md);
    color: var(--success);
    font-weight: 500;
    animation: fadeInUp 0.5s ease;
}

.form-success svg {
    width: 28px;
    height: 28px;
    color: var(--success);
}

/* ---- Footer ---- */
.footer {
    background: var(--bg-dark);
    color: rgba(255, 255, 255, 0.7);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
    gap: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-brand p {
    font-size: 14px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.5);
}

.footer-links h4,
.footer-contact h4 {
    font-size: 16px;
    font-weight: 600;
    color: #fff;
    margin-bottom: 20px;
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
    transition: var(--transition);
}

.footer-links a:hover {
    color: #fff;
    padding-left: 4px;
}

.footer-contact p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
    line-height: 2;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 0;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.4);
}

.beian-link {
    color: rgba(255, 255, 255, 0.4);
}

.beian-link:hover {
    color: rgba(255, 255, 255, 0.7);
}

/* ---- Back to Top ---- */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 50%;
    box-shadow: var(--shadow-lg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-card:nth-child(3) {
        grid-column: auto;
    }

    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .ai-highlight {
        grid-template-columns: 1fr;
        padding: 32px;
    }

    .ai-highlight-visual {
        display: none;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 64px 0;
    }

    .menu-toggle {
        display: flex;
    }

    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--bg-white);
        box-shadow: var(--shadow-xl);
        padding: 80px 32px 32px;
        transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    }

    .nav.open {
        right: 0;
    }

    .nav-list {
        flex-direction: column;
        gap: 24px;
    }

    .nav-link {
        font-size: 18px;
        color: var(--text) !important;
    }

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

    .hero-btns {
        flex-direction: column;
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

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

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

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

    .ai-tab-nav {
        flex-direction: column;
    }

    .contact-form-wrap {
        padding: 24px;
    }
}