/* ============================================
   Apple-Style Website - China AI Development
   Clean, Minimalist, High-End Design
   ============================================ */

/* CSS Variables */
:root {
    --white: #ffffff;
    --black: #000000;
    --gray-100: #f5f5f7;
    --gray-200: #e8e8ed;
    --gray-300: #d2d2d7;
    --gray-400: #86868b;
    --gray-500: #6e6e73;
    --gray-600: #424245;
    --gray-700: #1d1d1f;
    --blue-accent: #0071e3;
    --blue-hover: #0077ed;
    --green-accent: #34c759;
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-700);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

ul {
    list-style: none;
}

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

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    letter-spacing: -0.02em;
}

h1 { font-size: 3rem; line-height: 1.1; }
h2 { font-size: 2.5rem; line-height: 1.2; }
h3 { font-size: 1.5rem; line-height: 1.3; }
h4 { font-size: 1.125rem; }

@media (max-width: 768px) {
    h1 { font-size: 2.25rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.25rem; }
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}

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

.logo-img {
    height: 40px;
    width: auto;
    max-width: 150px;
    object-fit: contain;
}

.logo-text-wrapper {
    display: flex;
    flex-direction: column;
    justify-content: center;
    line-height: 1.2;
}

.logo-text {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--gray-700);
    letter-spacing: 0.01em;
    white-space: nowrap;
}

.logo-full {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--gray-700);
    letter-spacing: 0.15em;
    white-space: nowrap;
}

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

.nav-links a {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--gray-600);
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--black);
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    background: linear-gradient(180deg, var(--white) 0%, var(--gray-100) 100%);
    position: relative;
    overflow: hidden;
}

.hero-content {
    text-align: center;
    max-width: 800px;
    z-index: 2;
}

.hero-title {
    margin-bottom: 24px;
}

.hero-line {
    display: block;
    font-size: 4rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.hero-line.accent {
    color: var(--blue-accent);
    font-weight: 600;
}

.hero-subtitle {
    font-size: 1rem;
    color: var(--gray-400);
    margin-bottom: 8px;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.hero-company {
    font-size: 1rem;
    color: var(--gray-500);
    margin-bottom: 16px;
    font-weight: 500;
}

.company-en {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--gray-400);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--gray-400);
    margin-bottom: 40px;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

@media (max-width: 768px) {
    .hero-line {
        font-size: 2.5rem;
    }
    .hero-subtitle {
        font-size: 1rem;
    }
    .hero-description {
        font-size: 1rem;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: 980px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--blue-accent);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--blue-hover);
    transform: scale(1.02);
}

.btn-secondary {
    background: transparent;
    color: var(--blue-accent);
    border: 1px solid var(--blue-accent);
}

.btn-secondary:hover {
    background: var(--blue-accent);
    color: var(--white);
}

.btn-full {
    width: 100%;
}

/* Hero Visual - Floating Cards */
.hero-visual {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.floating-card {
    position: absolute;
    background: var(--white);
    padding: 20px 28px;
    border-radius: 20px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.08);
    display: flex;
    align-items: center;
    gap: 12px;
    animation: float 6s ease-in-out infinite;
    opacity: 0.8;
}

.floating-card .card-icon {
    font-size: 1.5rem;
}

.floating-card span {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
}

.card-1 {
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.card-2 {
    top: 30%;
    right: 10%;
    animation-delay: 2s;
}

.card-3 {
    bottom: 25%;
    left: 15%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

@media (max-width: 1024px) {
    .hero-visual {
        display: none;
    }
}

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

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

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

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

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

.section-title {
    color: var(--gray-700);
    margin-bottom: 8px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-400);
    font-weight: 400;
}

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

.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.about-card {
    background: var(--gray-100);
    padding: 40px;
    border-radius: 24px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08);
}

.about-icon {
    font-size: 3rem;
    margin-bottom: 24px;
}

.about-card h3 {
    color: var(--gray-700);
    margin-bottom: 16px;
}

.about-card p {
    color: var(--gray-500);
    font-size: 0.9375rem;
    line-height: 1.7;
}

@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }
}

/* Products Section */
.products-section {
    background: var(--gray-100);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.product-card {
    background: var(--white);
    border-radius: 24px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.product-image {
    height: 200px;
    background: linear-gradient(135deg, var(--gray-200) 0%, var(--gray-300) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.product-placeholder {
    font-size: 3rem;
    font-weight: 700;
    color: var(--gray-400);
    opacity: 0.5;
}

.product-content {
    padding: 32px;
}

.product-tag {
    display: inline-block;
    background: var(--gray-100);
    color: var(--gray-600);
    font-size: 0.75rem;
    font-weight: 600;
    padding: 6px 12px;
    border-radius: 980px;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.product-card h3 {
    color: var(--gray-700);
    margin-bottom: 12px;
}

.product-card > .product-content > p {
    color: var(--gray-500);
    font-size: 0.9375rem;
    margin-bottom: 20px;
}

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

.product-features li {
    color: var(--gray-600);
    font-size: 0.875rem;
    padding-left: 20px;
    position: relative;
}

.product-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--green-accent);
    font-weight: 600;
}

@media (max-width: 1024px) {
    .products-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }
}

/* Vision Section */
.vision-section {
    background: var(--gray-700);
    color: var(--white);
}

.vision-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.vision-text h2 {
    margin-bottom: 24px;
}

.vision-quote {
    font-size: 1.5rem;
    font-weight: 300;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 48px;
    line-height: 1.6;
}

.vision-stats {
    display: flex;
    gap: 48px;
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--blue-accent);
    line-height: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
    margin-top: 8px;
}

.vision-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 400px;
}

.orbit {
    position: relative;
    width: 300px;
    height: 300px;
}

.orbit-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 4rem;
    z-index: 10;
}

.orbit-ring {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: pulse 4s ease-in-out infinite;
}

.ring-1 {
    width: 200px;
    height: 200px;
}

.ring-2 {
    width: 280px;
    height: 280px;
    animation-delay: 0.5s;
}

.ring-3 {
    width: 360px;
    height: 360px;
    animation-delay: 1s;
}

@keyframes pulse {
    0%, 100% { opacity: 0.3; transform: translate(-50%, -50%) scale(1); }
    50% { opacity: 0.6; transform: translate(-50%, -50%) scale(1.02); }
}

@media (max-width: 1024px) {
    .vision-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .vision-stats {
        justify-content: center;
    }
    .vision-visual {
        display: none;
    }
}

/* Contact Section */
.contact-section {
    background: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.contact-icon {
    font-size: 2rem;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border-radius: 12px;
}

.contact-item h4 {
    color: var(--gray-700);
    margin-bottom: 4px;
}

.contact-item a {
    color: var(--blue-accent);
    font-size: 1rem;
}

.contact-item a:hover {
    text-decoration: underline;
}

.contact-item p {
    color: var(--gray-500);
    font-size: 1rem;
}

.contact-form {
    background: var(--gray-100);
    padding: 40px;
    border-radius: 24px;
}

.contact-form h3 {
    margin-bottom: 24px;
    color: var(--gray-700);
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 16px 20px;
    font-size: 1rem;
    font-family: var(--font-main);
    border: 2px solid transparent;
    border-radius: 12px;
    background: var(--white);
    transition: border-color 0.3s ease;
}

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

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--gray-400);
}

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

@media (max-width: 1024px) {
    .contact-grid {
        grid-template-columns: 1fr;
    }
}

/* Footer */
.footer {
    background: var(--gray-700);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo-text,
.footer-brand .logo-sub {
    color: var(--white);
}

.footer-logo-img {
    height: 40px;
    width: auto;
    max-width: 150px;
    object-fit: contain;
    margin-bottom: 12px;
}

.footer-brand p {
    margin-top: 16px;
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
    line-height: 1.6;
}

.footer-links {
    display: flex;
    gap: 32px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.875rem;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--white);
}

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

.footer-bottom p {
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.75rem;
}

@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        gap: 32px;
        text-align: center;
    }
    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* Scroll Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Smooth Scroll Offset for Fixed Nav */
section[id] {
    scroll-margin-top: 80px;
}