/* ==========================================
   CSS Variables & Reset
   ========================================== */
:root {
    /* Colors from Centera logo - deep navy blue */
    --primary: #1a3a52;
    --primary-light: #2d5875;
    --primary-dark: #0f2333;
    --secondary: #4a90e2;
    --accent: #667eea;

    /* Neutral colors */
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-light: #718096;
    --bg-primary: #ffffff;
    --bg-secondary: #f7fafc;
    --bg-tertiary: #edf2f7;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #1a3a52 0%, #2d5875 100%);
    --gradient-accent: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-soft: linear-gradient(135deg, rgba(26, 58, 82, 0.05) 0%, rgba(74, 144, 226, 0.05) 100%);

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 20px 48px rgba(0, 0, 0, 0.15);

    /* Border radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 32px;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-family);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ==========================================
   Container & Layout
   ========================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.8;
}

/* ==========================================
   Navigation
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-md);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 1rem;
    text-decoration: none;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
}

.logo:hover {
    transform: translateY(-2px);
    background: rgba(26, 58, 82, 0.03);
}

.logo-img {
    height: 64px;
    width: auto;
}

.logo-text {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.3s ease;
    padding: 0.5rem 0;
    position: relative;
}

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

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

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

.nav-link.cta-button {
    background: var(--gradient-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.nav-link.cta-button::after {
    display: none;
}

.nav-link.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary);
    border-radius: 2px;
    transition: all 0.3s ease;
}

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

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
}

.hero-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('../images/shopping-mall-bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0.4;
    filter: grayscale(70%) blur(1.5px);
}

.hero-background::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg,
        rgba(247, 250, 252, 0.6) 0%,
        rgba(237, 242, 247, 0.5) 50%,
        rgba(247, 250, 252, 0.6) 100%
    );
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
    animation: float 20s infinite ease-in-out;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: var(--gradient-primary);
    top: -250px;
    right: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: var(--gradient-accent);
    bottom: -200px;
    left: -100px;
    animation-delay: 5s;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, #4a90e2 0%, #667eea 100%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% {
        transform: translate(0, 0) scale(1);
    }
    33% {
        transform: translate(50px, -50px) scale(1.1);
    }
    66% {
        transform: translate(-50px, 50px) scale(0.9);
    }
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-text {
    animation: fadeInUp 0.8s ease;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
    letter-spacing: -0.02em;
}

.highlight {
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: var(--spacing-lg);
}

.btn {
    padding: 1rem 2rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: white;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-3px);
}

.btn-full {
    width: 100%;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 2px solid var(--bg-tertiary);
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.hero-image {
    position: relative;
    height: 500px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--spacing-md);
}

.hero-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.card-float {
    animation: cardFloat 3s infinite ease-in-out;
}

.card-float-delayed {
    animation: cardFloat 3s infinite ease-in-out 1s;
}

.card-float-more-delayed {
    animation: cardFloat 3s infinite ease-in-out 2s;
}

@keyframes cardFloat {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-15px);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card-content {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.card-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.card-text h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.card-text p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* ==========================================
   About Section
   ========================================== */
.about {
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.about-text h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
}

.about-list {
    list-style: none;
    margin-top: var(--spacing-md);
}

.about-list li {
    font-size: 1.1rem;
    color: var(--text-secondary);
    padding: 0.75rem 0;
    display: flex;
    align-items: center;
}

.visual-card {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    text-align: center;
}

.about-logo {
    width: 200px;
    height: auto;
    margin-bottom: var(--spacing-md);
}

.visual-info h4 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
}

.visual-info p {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* ==========================================
   Features Section
   ========================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

.feature-card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ==========================================
   Benefits Section
   ========================================== */
.benefits {
    background: var(--bg-secondary);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-md);
}

.benefit-card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

.benefit-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.benefit-number {
    position: absolute;
    top: -20px;
    right: 20px;
    font-size: 6rem;
    font-weight: 900;
    color: rgba(26, 58, 82, 0.05);
    line-height: 1;
}

.benefit-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-sm);
    position: relative;
    z-index: 1;
}

.benefit-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    position: relative;
    z-index: 1;
}

/* ==========================================
   Technology Section
   ========================================== */
.tech-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.tech-column h3 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.tech-list {
    list-style: none;
}

.tech-list li {
    background: white;
    padding: 1.25rem;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    border-left: 4px solid var(--primary);
}

.tech-list li:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-md);
}

.tech-name {
    display: block;
    font-weight: 700;
    color: var(--primary);
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.tech-desc {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.tech-features {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.tech-feature {
    background: var(--gradient-soft);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    text-align: center;
}

.tech-feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.tech-feature h4 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-xs);
}

.tech-feature p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

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

.contact-content-centered {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.contact-content-centered h2 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
}

.contact-description {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    text-align: left;
}

.contact-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.contact-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.contact-item a {
    color: var(--secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.contact-item a:hover {
    color: var(--primary);
}

.contact-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--primary);
    color: white;
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-logo-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: var(--spacing-sm);
}

.footer-logo-wrapper {
    background: white;
    padding: 0.75rem;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.footer-logo-img {
    height: 60px;
    width: auto;
    filter: none;
}

.footer-logo-text {
    font-size: 1.75rem;
    font-weight: 800;
    color: white;
    letter-spacing: -0.02em;
}

.footer-logo p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
}

.footer-links h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a,
.footer-contact a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover,
.footer-contact a:hover {
    color: white;
}

.footer-contact h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

.footer-bottom a {
    color: white;
    text-decoration: none;
    font-weight: 600;
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .hero-image {
        height: auto;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .tech-content {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 768px) {
    .logo-img {
        height: 48px;
    }

    .logo-text {
        font-size: 1.5rem;
    }

    .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        transition: all 0.3s ease;
        gap: 0;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
    }

    .nav-links li {
        width: 100%;
        text-align: center;
        padding: var(--spacing-sm) 0;
        border-bottom: 1px solid var(--bg-tertiary);
    }

    .nav-link.cta-button {
        display: block;
        margin-top: var(--spacing-sm);
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

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

    .hero-stats {
        grid-template-columns: 1fr;
    }

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

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

    .tech-features {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .section {
        padding: var(--spacing-lg) 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .logo-img {
        height: 40px;
    }

    .logo-text {
        font-size: 1.25rem;
    }

    .footer-logo-container {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .footer-logo-text {
        font-size: 1.5rem;
    }
}

/* ==========================================
   Utility Classes
   ========================================== */
.hidden {
    display: none !important;
}

.visible {
    display: block !important;
}

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

.mt-lg {
    margin-top: var(--spacing-lg);
}

.mb-lg {
    margin-bottom: var(--spacing-lg);
}