/* ===========================================
   NEXGREEN - PROFESSIONAL AUSTRALIAN ENERGY SOLUTIONS
   Professional Corporate Website Design
   =========================================== */

/* ===========================================
   RESET & BASE STYLES
   =========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: 'Inter', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--text-primary);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

button {
    cursor: pointer;
    font-family: inherit;
    font-size: inherit;
}

ul, ol {
    list-style: none;
}

/* ===========================================
   CSS CUSTOM VARIABLES - DESIGN SYSTEM
   =========================================== */
:root {
    /* Colors - NexGreen Professional Palette (Based on Logo) */
    --primary-blue: #0c3b5e;
    --primary-blue-light: #1e5a8a;
    --secondary-blue: #2e7bc9;
    --accent-green: #16a34a;
    --accent-green-light: #22c55e;
    --text-primary: #111827;
    --text-secondary: #374151;
    --text-light: #6b7280;
    --white: #ffffff;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;

    /* Typography - Professional English Readability */
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    --font-size-6xl: 3.75rem;

    /* Line Heights - Optimal Readability */
    --line-height-tight: 1.2;
    --line-height-normal: 1.6;
    --line-height-relaxed: 1.8;

    /* Spacing - Professional Layout */
    --section-padding: 120px;
    --section-padding-mobile: 80px;
    --container-padding: 24px;
    --card-padding: 32px;

    /* Border Radius - Modern & Clean */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;

    /* Shadows - Professional Depth */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-card: 0 8px 30px rgba(0, 0, 0, 0.08);
    --shadow-card-hover: 0 20px 50px rgba(10, 47, 82, 0.15);

    /* Transitions - Smooth Interactions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);

    /* Breakpoints - Responsive Design */
    --breakpoint-sm: 640px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;
    --breakpoint-xl: 1280px;
}

/* ===========================================
   CONTAINER - Responsive Layout
   =========================================== */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* ===========================================
   BUTTONS - Professional Call-to-Actions
   =========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-size: var(--font-size-base);
    font-weight: 600;
    letter-spacing: 0.3px;
    border-radius: var(--radius-md);
    transition: var(--transition);
    text-transform: none;
    border: none;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-green), var(--accent-green-light));
    color: var(--white);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--accent-green-light), var(--accent-green));
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(16, 185, 129, 0.4);
}

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

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

/* ===========================================
   HEADER & NAVIGATION - Professional Corporate
   =========================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
}

.header.scrolled {
    padding: 12px 0;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

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

.logo {
    transition: var(--transition);
}

.logo img {
    max-height: 64px;
    height: 64px;
    width: auto;
    transition: var(--transition);
    animation: logoFadeIn 0.8s ease-out;
}

.logo:hover {
    transform: scale(1.05);
}

.header.scrolled .logo img {
    max-height: 52px;
    height: 52px;
}

@keyframes logoFadeIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.footer-logo img {
    max-height: 80px;
    height: 80px;
    width: auto;
    margin-bottom: 20px;
    animation: logoFadeIn 0.8s ease-out 0.2s both;
}

.nav {
    display: flex;
    gap: 40px;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-sm);
    letter-spacing: 0.5px;
    transition: var(--transition);
    position: relative;
    padding: 8px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-green);
    transition: var(--transition);
}

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

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

.lang-select {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--gray-200);
    background: var(--white);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.lang-select:hover {
    border-color: var(--accent-green);
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    cursor: pointer;
    z-index: 1001;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--primary-blue);
    border-radius: 3px;
    transition: var(--transition);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background: var(--white);
    box-shadow: -5px 0 20px rgba(0,0,0,0.1);
    z-index: 1000;
    transition: right 0.3s ease;
    padding: 100px 30px 30px;
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-nav {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.mobile-menu-nav .nav-link {
    font-size: var(--font-size-lg);
    padding: 15px 0;
    border-bottom: 1px solid var(--gray-100);
}

.mobile-menu .lang-select {
    width: 100%;
    margin-top: 30px;
}

/* Mobile Menu Overlay */
.mobile-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.mobile-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* ===========================================
   HERO SECTION - Impactful Full Screen
   =========================================== */
.hero {
    position: relative;
    height: 100vh;
    min-height: 700px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-short {
    height: 50vh !important;
    min-height: 350px !important;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
    animation: subtleZoom 30s ease-in-out infinite alternate;
    filter: brightness(1.08) contrast(1.05) saturate(1.1);
}

@keyframes subtleZoom {
    from {
        transform: scale(1);
    }
    to {
        transform: scale(1.08);
    }
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        135deg,
        rgba(10, 47, 82, 0.92) 0%,
        rgba(10, 47, 82, 0.75) 40%,
        rgba(10, 47, 82, 0.55) 100%
    );
    z-index: -1;
}

.hero-content {
    max-width: 700px;
    padding-top: 80px;
}

.hero-subtitle {
    display: inline-block;
    color: var(--accent-green-light);
    font-size: var(--font-size-sm);
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 24px;
    padding: 8px 16px;
    background: rgba(16, 185, 129, 0.1);
    border-radius: 50px;
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.hero-title {
    font-size: var(--font-size-5xl);
    font-weight: 700;
    line-height: var(--line-height-tight);
    color: var(--white);
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

.hero-desc {
    font-size: var(--font-size-xl);
    line-height: var(--line-height-normal);
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 40px;
    font-weight: 400;
}

.hero-features {
    margin: 24px 0 40px;
}

.hero-feature {
    color: rgba(255, 255, 255, 0.95);
    font-size: var(--font-size-base);
    line-height: 1.6;
    margin-bottom: 12px;
    padding-left: 8px;
}

.about-features {
    margin: 24px 0;
}

.about-features p {
    font-size: var(--font-size-base);
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 10px;
    padding-left: 8px;
}

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

.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
}

.scroll-indicator span {
    display: block;
    width: 24px;
    height: 40px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 25px;
    position: relative;
}

.scroll-indicator span::after {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--accent-green);
    border-radius: 2px;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
    40% {
        transform: translateX(-50%) translateY(10px);
        opacity: 0.7;
    }
    60% {
        transform: translateX(-50%) translateY(5px);
        opacity: 0.9;
    }
}

/* ===========================================
   SECTION - Professional Layout
   =========================================== */
.section {
    padding: var(--section-padding) 0;
    position: relative;
    overflow: hidden;
}

.section-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.section-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.06;
}

.section-blue {
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-blue-light) 100%);
}

.section-blue .section-title,
.section-blue .section-subtitle,
.section-blue .section-desc {
    color: var(--white);
}

/* ===========================================
   SECTION HEADER - Clear Hierarchy
   =========================================== */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 70px;
}

.section-subtitle {
    display: inline-block;
    color: var(--accent-green);
    font-size: var(--font-size-sm);
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 16px;
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: var(--line-height-tight);
    color: var(--text-primary);
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.section-desc {
    font-size: var(--font-size-lg);
    line-height: var(--line-height-normal);
    color: var(--text-secondary);
}

/* ===========================================
   SOLUTIONS GRID - Professional Cards
   =========================================== */
.solutions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.solution-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: var(--transition-slow);
    position: relative;
    border: 1px solid var(--gray-100);
}

.solution-card:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-card-hover);
}

.solution-card-image {
    width: 100%;
    height: 220px;
    overflow: hidden;
}

.solution-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.solution-card:hover .solution-card-image img {
    transform: scale(1.1);
}

.solution-card-content {
    padding: var(--card-padding);
}

.solution-card-icon {
    font-size: 36px;
    margin-bottom: 16px;
}

.solution-card-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    line-height: var(--line-height-tight);
}

.solution-card-desc {
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.solution-card-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--accent-green);
    font-weight: 600;
    font-size: var(--font-size-sm);
    transition: var(--transition);
}

.solution-card-link:hover {
    gap: 12px;
}

/* ===========================================
   ABOUT SECTION - Two Column Layout
   =========================================== */
.about-grid,
.two-column {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-image,
.column-image {
    position: relative;
}

.about-image img,
.column-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.about-content h3,
.column-content h3 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 24px;
    line-height: var(--line-height-tight);
}

.about-content p,
.column-content p {
    font-size: var(--font-size-lg);
    line-height: var(--line-height-relaxed);
    color: var(--text-secondary);
    margin-bottom: 20px;
}

/* ===========================================
   STATS - Professional Data Display
   =========================================== */
.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.stat-item {
    text-align: center;
    padding: 24px;
    background: var(--gray-50);
    border-radius: var(--radius-lg);
}

.stat-number {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    color: var(--accent-green);
    margin-bottom: 8px;
    line-height: 1;
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ===========================================
   SERVICES GRID - Professional Presentation
   =========================================== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.service-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-card);
    transition: var(--transition-slow);
    border: 1px solid var(--gray-100);
    position: relative;
}

.service-card:hover {
    transform: translateY(-12px);
    box-shadow: var(--shadow-card-hover);
}

.service-card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.service-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.service-card:hover .service-card-image img {
    transform: scale(1.1);
}

.service-card-content {
    padding: var(--card-padding);
}

.service-card-number {
    display: inline-block;
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--accent-green);
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.service-card-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.service-card-desc {
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--text-secondary);
}

/* ===========================================
   CONTACT PAGE - Professional Form
   =========================================== */
.contact-page {
    position: relative;
    padding: 180px 0 120px;
    min-height: 100vh;
}

.contact-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
}

.contact-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: brightness(0.95);
}

.contact-bg-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        180deg,
        rgba(10, 47, 82, 0.85) 0%,
        rgba(10, 47, 82, 0.92) 100%
    );
    z-index: -1;
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: start;
}

.contact-form {
    background: var(--white);
    padding: 50px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.contact-form h3 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.contact-form p {
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: var(--font-size-lg);
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

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

.form-group.full {
    grid-column: 1 / -1;
}

.form-group label {
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: 0.3px;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 14px 16px;
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    font-family: inherit;
    transition: var(--transition);
    background: var(--white);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-green);
    box-shadow: 0 0 0 4px rgba(16, 185, 129, 0.1);
}

.contact-form .btn {
    margin-top: 12px;
    width: 100%;
}

.contact-info-section {
    position: relative;
}

.contact-info-image {
    width: 100%;
    margin-bottom: 32px;
}

.contact-info-image img {
    width: 100%;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.contact-info-item {
    display: flex;
    gap: 20px;
    margin-bottom: 28px;
    padding: 24px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
}

.contact-info-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.contact-info-text h4 {
    color: var(--white);
    font-weight: 700;
    margin-bottom: 8px;
    font-size: var(--font-size-lg);
}

.contact-info-text p {
    color: rgba(255, 255, 255, 0.85);
    line-height: var(--line-height-normal);
    font-size: var(--font-size-base);
}

.contact-info-text a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
}

.contact-info-text a:hover {
    color: rgba(255, 255, 255, 0.85);
}

/* ===========================================
   FOOTER - Professional Corporate
   =========================================== */
.footer {
    background: var(--primary-blue);
    padding: 80px 0 30px;
    color: rgba(255, 255, 255, 0.8);
}

.footer-top {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.2fr;
    gap: 50px;
    margin-bottom: 50px;
}

.footer-brand h3 {
    color: var(--white);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: var(--font-size-sm);
    line-height: var(--line-height-relaxed);
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 24px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transition: var(--transition);
    font-size: 20px;
}

.social-link:hover {
    background: var(--accent-green);
    transform: translateY(-3px);
}

.footer-column h4 {
    color: var(--white);
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul li a {
    color: rgba(255, 255, 255, 0.7);
    font-size: var(--font-size-sm);
    transition: var(--transition);
    display: inline-block;
}

.footer-column ul li a:hover {
    color: var(--accent-green-light);
    transform: translateX(4px);
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

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

/* ===========================================
   ANIMATIONS - Professional Scroll Effects
   =========================================== */
.animate-on-scroll,
.animate-on-scroll-left,
.animate-on-scroll-right {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1), 
                transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: opacity, transform;
    backface-visibility: hidden;
}

.animate-on-scroll-left {
    transform: translateX(-40px);
}

.animate-on-scroll-right {
    transform: translateX(40px);
}

.animate-on-scroll.animated,
.animate-on-scroll-left.animated,
.animate-on-scroll-right.animated {
    opacity: 1;
    transform: translateY(0) translateX(0);
    will-change: auto;
}

/* Performance optimizations */
img {
    backface-visibility: hidden;
    transform: translateZ(0);
}

/* ===========================================
   RESPONSIVE DESIGN - Mobile First
   =========================================== */
@media (max-width: 1024px) {
    .solutions-grid,
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-grid,
    .two-column {
        grid-template-columns: 1fr;
        gap: 50px;
    }
    
    /* 在移动端，所有区块统一图片在前，内容在后 */
    .two-column {
        display: flex;
        flex-direction: column;
    }
    
    .two-column .column-image {
        order: -1;
    }

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

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

    .nav {
        gap: 24px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: var(--section-padding-mobile);
    }

    .logo img {
        max-height: 52px;
        height: 52px;
    }

    .header.scrolled .logo img {
        max-height: 44px;
        height: 44px;
    }

    .footer-logo img {
        max-height: 64px;
        height: 64px;
    }

    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .hero-desc {
        font-size: var(--font-size-lg);
    }

    .hero-feature {
        font-size: var(--font-size-sm);
    }

    .section-title {
        font-size: var(--font-size-3xl);
    }

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

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

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

    .footer-top {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-social {
        justify-content: center;
    }

    /* Show mobile menu */
    .nav {
        display: none;
    }

    .header-content {
        justify-content: space-between;
    }

    .header-right {
        display: flex;
        align-items: center;
        gap: 4px;
    }

    .header-content .lang-select {
        display: block;
        margin-right: 0;
    }

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

    /* 确保移动端所有两列布局都是图片在前，内容在后 */
    .two-column {
        display: flex;
        flex-direction: column;
    }
    
    .two-column .column-image {
        order: -1;
    }

    .hero-short {
        height: 40vh !important;
        min-height: 280px !important;
    }

    .contact-form {
        padding: 32px;
    }
}

@media (max-width: 480px) {
    /* 确保小屏幕移动端所有两列布局都是图片在前，内容在后 */
    .two-column {
        display: flex;
        flex-direction: column;
    }
    
    .two-column .column-image {
        order: -1;
    }

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

    .btn {
        width: 100%;
    }
}