/* ============================================
   Kunming De'ai Technology Co., Ltd.
   Dark Theme - Professional IT Services
   ============================================ */

:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-card: #16161f;
    --bg-card-hover: #1c1c2a;
    --accent: #00d4ff;
    --accent-dim: #0099bb;
    --accent-glow: rgba(0, 212, 255, 0.15);
    --text-primary: #e8e8f0;
    --text-secondary: #9090a0;
    --text-muted: #606070;
    --border: #222233;
    --border-light: #2a2a3e;
    --gradient-1: linear-gradient(135deg, #00d4ff, #7c3aed);
    --gradient-2: linear-gradient(135deg, #00d4ff 0%, #0ea5e9 50%, #7c3aed 100%);
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: #fff;
}

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

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

/* ============================================
   HEADER / NAVIGATION
   ============================================ */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: background 0.3s;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    width: 38px;
    height: 38px;
    background: var(--gradient-1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    font-size: 1.1rem;
    color: #fff;
}

.logo span {
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 8px;
}

.nav-links a {
    padding: 8px 16px;
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-cta {
    background: var(--gradient-1) !important;
    color: #fff !important;
    padding: 8px 20px !important;
    border-radius: 8px !important;
    font-weight: 600 !important;
}

.nav-cta:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    padding: 8px;
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    padding-top: 72px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(0, 212, 255, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 50%, rgba(124, 58, 237, 0.06) 0%, transparent 50%);
    pointer-events: none;
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 50px;
    font-size: 0.8rem;
    color: var(--accent);
    margin-bottom: 24px;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.hero h1 .highlight {
    background: var(--gradient-2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin-bottom: 36px;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.95rem;
    border: none;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: var(--gradient-1);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 212, 255, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}

.btn-secondary:hover {
    border-color: var(--accent);
    background: rgba(0, 212, 255, 0.05);
    transform: translateY(-2px);
}

/* ============================================
   SECTION COMMON
   ============================================ */

.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-tag {
    display: inline-block;
    padding: 4px 14px;
    background: rgba(0, 212, 255, 0.08);
    border: 1px solid rgba(0, 212, 255, 0.15);
    border-radius: 50px;
    font-size: 0.8rem;
    color: var(--accent);
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.section-header p {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    font-size: 1.05rem;
}

/* ============================================
   SERVICES
   ============================================ */

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 24px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 40px 32px;
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-1);
    opacity: 0;
    transition: opacity 0.4s;
}

.service-card:hover {
    border-color: var(--border-light);
    transform: translateY(-4px);
    background: var(--bg-card-hover);
}

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

.service-icon {
    width: 56px;
    height: 56px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
}

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

/* ============================================
   ABOUT
   ============================================ */

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: 24px;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.stat-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 28px;
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-1);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 4px;
}

/* ============================================
   WHY CHOOSE US
   ============================================ */

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 28px 24px;
    transition: all 0.3s;
}

.feature-card:hover {
    border-color: var(--border-light);
    transform: translateY(-2px);
}

.feature-card .icon {
    font-size: 1.8rem;
    margin-bottom: 14px;
}

.feature-card h4 {
    font-size: 1.05rem;
    margin-bottom: 8px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.88rem;
}

/* ============================================
   TEAM
   ============================================ */

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
}

.team-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 36px 24px;
    text-align: center;
    transition: all 0.3s;
}

.team-card:hover {
    border-color: var(--border-light);
    transform: translateY(-4px);
}

.team-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--gradient-1);
    margin: 0 auto 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: #fff;
    font-weight: 700;
}

.team-card h4 {
    font-size: 1rem;
    margin-bottom: 4px;
}

.team-card .role {
    font-size: 0.85rem;
    color: var(--accent);
    margin-bottom: 12px;
}

.team-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============================================
   CONTACT
   ============================================ */

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

.contact-info h3 {
    font-size: 1.8rem;
    margin-bottom: 24px;
}

.contact-details {
    list-style: none;
}

.contact-details li {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
}

.contact-details .icon {
    width: 44px;
    height: 44px;
    min-width: 44px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
}

.contact-details .label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.contact-details .value {
    color: var(--text-primary);
    font-weight: 500;
}

.contact-form {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 36px;
}

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

.form-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 6px;
    font-weight: 500;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 0.95rem;
    font-family: inherit;
    transition: border-color 0.3s;
}

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

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

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

/* ============================================
   FOOTER
   ============================================ */

.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-top: 12px;
    max-width: 300px;
}

.footer-heading {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

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

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.88rem;
}

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

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.83rem;
}

/* ============================================
   PAGE HEADER (inner pages)
   ============================================ */

.page-header {
    padding-top: 136px;
    padding-bottom: 48px;
    background:
        radial-gradient(ellipse at 50% 0%, rgba(0, 212, 255, 0.05) 0%, transparent 60%);
    text-align: center;
}

.page-header h1 {
    font-size: 2.8rem;
    font-weight: 800;
    margin-bottom: 12px;
}

.page-header p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   CONTENT PAGES (privacy, terms)
   ============================================ */

.content-page {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 48px;
    margin-bottom: 60px;
}

.content-page h2 {
    font-size: 1.6rem;
    margin-top: 40px;
    margin-bottom: 16px;
    color: var(--accent);
}

.content-page h3 {
    font-size: 1.2rem;
    margin-top: 32px;
    margin-bottom: 12px;
}

.content-page p {
    color: var(--text-secondary);
    margin-bottom: 16px;
    line-height: 1.8;
}

.content-page ul,
.content-page ol {
    color: var(--text-secondary);
    margin-bottom: 16px;
    padding-left: 24px;
}

.content-page li {
    margin-bottom: 8px;
}

.content-page strong {
    color: var(--text-primary);
}

.last-updated {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 24px;
    font-style: italic;
}

/* ============================================
   SERVICES PAGE
   ============================================ */

.service-detail {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 40px;
    margin-bottom: 24px;
}

.service-detail h3 {
    font-size: 1.3rem;
    margin-bottom: 16px;
}

.service-detail p {
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.service-detail ul {
    color: var(--text-secondary);
    padding-left: 20px;
    margin-bottom: 12px;
}

.service-detail li {
    margin-bottom: 6px;
}

/* ============================================
   RESPONSIVE
   ============================================ */

@media (max-width: 768px) {
    .mobile-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 16px 24px;
        gap: 4px;
    }

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

    .nav-links a {
        padding: 12px 16px;
    }

    .hero h1 {
        font-size: 2.2rem;
    }

    .about-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

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

    .section {
        padding: 60px 0;
    }

    .section-header h2 {
        font-size: 1.8rem;
    }

    .content-page {
        padding: 24px;
    }

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

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }

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

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

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

/* ============================================
   ANIMATIONS
   ============================================ */

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

.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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