/* ============================================
   Cheng Technology Group - Corporate Identity
   Dark Navy Theme with Metallic Blue Accents
   ============================================ */

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

:root {
    /* Core CI Colors */
    --bg-deep: #080c14;
    --bg-primary: #0a0f1c;
    --bg-secondary: #0d1424;
    --bg-card: #111827;
    --bg-card-hover: #162033;

    /* Metallic Blue Gradient */
    --blue-dark: #2a6090;
    --blue-mid: #4a90c4;
    --blue-light: #6bb3e0;
    --blue-pale: #8ecae6;

    /* Text Colors */
    --text-primary: #e2e8f0;
    --text-secondary: #8494a7;
    --text-muted: #4a5568;
    --text-accent: #6bb3e0;

    /* Borders & Surfaces */
    --border-color: rgba(106, 179, 224, 0.1);
    --border-hover: rgba(106, 179, 224, 0.25);
    --glow: rgba(106, 179, 224, 0.15);
    --glow-strong: rgba(106, 179, 224, 0.3);

    /* Spacing */
    --section-padding: 6rem 0;
    --container-max: 1200px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-deep);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Utility Classes
   ============================================ */

.text-gradient {
    background: linear-gradient(135deg, var(--blue-light), var(--blue-mid));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-label {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--blue-mid);
    margin-bottom: 1rem;
}

.section-header h2 {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 1px;
}

.section-divider {
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, var(--blue-dark), var(--blue-light), var(--blue-dark));
    margin: 1.5rem auto 0;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: 0.85rem 2.2rem;
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-decoration: none;
    border-radius: 4px;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--blue-dark), var(--blue-mid));
    color: #fff;
    box-shadow: 0 4px 15px rgba(42, 96, 144, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--blue-mid), var(--blue-light));
    box-shadow: 0 6px 25px rgba(42, 96, 144, 0.5);
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    color: var(--blue-light);
    border: 1px solid var(--border-hover);
}

.btn-outline:hover {
    background: rgba(106, 179, 224, 0.08);
    border-color: var(--blue-light);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    text-align: center;
}

/* ============================================
   Header & Navigation
   ============================================ */

header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(8, 12, 20, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

header.scrolled {
    background: rgba(8, 12, 20, 0.95);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

nav {
    max-width: var(--container-max);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    display: flex;
    flex-direction: column;
    text-decoration: none;
    line-height: 1.2;
}

.logo-cheng {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: 4px;
    background: linear-gradient(180deg, var(--blue-pale), var(--blue-mid), var(--blue-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-sub {
    font-size: 0.55rem;
    font-weight: 500;
    letter-spacing: 3.5px;
    color: var(--text-secondary);
    text-transform: uppercase;
}

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

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-secondary);
    transition: all 0.3s ease;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: linear-gradient(90deg, var(--blue-mid), transparent);
    transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--blue-light);
}

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

/* ============================================
   Hero Section
   ============================================ */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    background: var(--bg-deep);
    padding: 0;
    margin: 0;
    border-radius: 0;
    box-shadow: none;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 60% at 50% 40%, rgba(42, 96, 144, 0.12) 0%, transparent 70%),
        radial-gradient(ellipse 40% 30% at 70% 60%, rgba(106, 179, 224, 0.06) 0%, transparent 60%);
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 2rem;
}

.hero-title {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.3rem;
    margin-bottom: 1.5rem;
}

.hero-cheng {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: clamp(3.5rem, 10vw, 7rem);
    font-weight: 700;
    letter-spacing: 12px;
    line-height: 1;
    background: linear-gradient(180deg,
        var(--blue-pale) 0%,
        var(--blue-light) 30%,
        var(--blue-mid) 60%,
        var(--blue-dark) 100%
    );
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 10px rgba(106, 179, 224, 0.2));
}

.hero-tech {
    font-family: 'Inter', sans-serif;
    font-size: clamp(0.8rem, 2.5vw, 1.2rem);
    font-weight: 400;
    letter-spacing: 8px;
    color: var(--text-secondary);
    text-transform: uppercase;
}

.hero-tagline {
    font-size: clamp(0.9rem, 2vw, 1.15rem);
    font-weight: 300;
    font-style: italic;
    color: var(--text-muted);
    letter-spacing: 3px;
    margin-bottom: 2rem;
}

.hero-divider {
    width: 80px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--blue-mid), transparent);
    margin: 0 auto 2rem;
}

.hero-description {
    max-width: 600px;
    margin: 0 auto 2.5rem;
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ============================================
   About Section
   ============================================ */

.about {
    padding: var(--section-padding);
    background: var(--bg-primary);
    border-radius: 0;
    box-shadow: none;
    margin: 0;
}

.about-grid {
    display: grid;
    gap: 3rem;
}

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

.about-text p {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.9;
    margin-bottom: 1.5rem;
}

.about-values {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

.value-card {
    text-align: center;
    padding: 2.5rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.4s ease;
    opacity: 0;
    transform: translateY(30px);
}

.value-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.value-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: 0 8px 40px rgba(106, 179, 224, 0.08);
    transform: translateY(-4px);
}

.value-card.visible:hover {
    transform: translateY(-4px);
}

.value-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto 1.5rem;
    color: var(--blue-mid);
}

.value-icon svg {
    width: 100%;
    height: 100%;
}

.value-card h3 {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: 1px;
    margin-bottom: 0.75rem;
}

.value-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   Our Companies Section
   ============================================ */

.companies {
    padding: var(--section-padding);
    background: var(--bg-deep);
    border-radius: 0;
    box-shadow: none;
    margin: 0;
}

.companies-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2.5rem;
}

.company-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 3rem 2.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: all 0.4s ease;
    opacity: 0;
    transform: translateY(30px);
}

.company-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.company-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: 0 12px 50px rgba(106, 179, 224, 0.08);
    transform: translateY(-6px);
}

.company-card.visible:hover {
    transform: translateY(-6px);
}

.company-logo {
    width: 180px;
    height: 180px;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.company-logo img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: 8px;
}

.company-info h3 {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.5px;
    margin-bottom: 0.4rem;
}

.company-tagline {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--blue-mid);
    letter-spacing: 1px;
    margin-bottom: 1rem;
}

.company-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    max-width: 360px;
}

@media (max-width: 768px) {
    .companies-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Services Section
   ============================================ */

.services {
    padding: var(--section-padding);
    background: var(--bg-deep);
    border-radius: 0;
    box-shadow: none;
    margin: 0;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.service-card {
    padding: 2.5rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(30px);
}

.service-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--blue-dark), var(--blue-light), var(--blue-dark));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.service-card:hover {
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
    box-shadow: 0 8px 40px rgba(106, 179, 224, 0.08);
    transform: translateY(-4px);
}

.service-card.visible:hover {
    transform: translateY(-4px);
}

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

.service-icon {
    width: 44px;
    height: 44px;
    margin-bottom: 1.5rem;
    color: var(--blue-mid);
}

.service-icon svg {
    width: 100%;
    height: 100%;
}

.service-card h3 {
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: 0.5px;
    margin-bottom: 0.75rem;
}

.service-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   Contact Section
   ============================================ */

.contact {
    padding: var(--section-padding);
    background: var(--bg-primary);
    border-radius: 0;
    box-shadow: none;
    margin: 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.contact-intro {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 2.5rem;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.contact-item svg {
    width: 22px;
    height: 22px;
    color: var(--blue-mid);
    flex-shrink: 0;
}

.contact-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 0.2rem;
}

.contact-item a,
.contact-item span {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.3s ease;
}

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

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.9rem 1.2rem;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    outline: none;
}

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

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--blue-mid);
    box-shadow: 0 0 0 3px rgba(74, 144, 196, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 130px;
}

/* ============================================
   Footer
   ============================================ */

footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 2rem;
    margin: 0;
}

.footer-content {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.footer-brand {
    margin-bottom: 2rem;
}

.footer-logo-cheng {
    display: block;
    font-family: 'Rajdhani', 'Inter', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 5px;
    background: linear-gradient(180deg, var(--blue-pale), var(--blue-mid));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-logo-sub {
    display: block;
    font-size: 0.5rem;
    font-weight: 500;
    letter-spacing: 3px;
    color: var(--text-secondary);
    text-transform: uppercase;
    margin-top: 0.2rem;
}

.footer-tagline {
    font-size: 0.8rem;
    font-style: italic;
    color: var(--text-secondary);
    margin-top: 0.5rem;
    letter-spacing: 1px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    transition: color 0.3s ease;
}

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

.footer-bottom p {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* ============================================
   Animations
   ============================================ */

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

.hero-content {
    animation: fadeInUp 1s ease forwards;
}

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

.hero-tech {
    animation: fadeInUp 0.8s ease 0.15s forwards;
    opacity: 0;
}

.hero-tagline {
    animation: fadeInUp 0.8s ease 0.3s forwards;
    opacity: 0;
}

.hero-divider {
    animation: fadeInUp 0.8s ease 0.45s forwards;
    opacity: 0;
}

.hero-description {
    animation: fadeInUp 0.8s ease 0.55s forwards;
    opacity: 0;
}

.hero-actions {
    animation: fadeInUp 0.8s ease 0.65s forwards;
    opacity: 0;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 4rem 0;
    }

    .mobile-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(8, 12, 20, 0.98);
        padding: 1.5rem 2rem;
        gap: 1.5rem;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.open {
        display: flex;
    }

    .hero-cheng {
        letter-spacing: 6px;
    }

    .hero-tech {
        letter-spacing: 4px;
    }

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

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

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .footer-links {
        flex-wrap: wrap;
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    nav {
        padding: 0.8rem 1.5rem;
    }

    .section-container {
        padding: 0 1.5rem;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 280px;
        text-align: center;
    }
}