/* about.css */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            color: #333;
        }

        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 0 20px;
        }

        /* Header */
        header {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(10px);
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 1000;
            box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
        }

        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 15px 0;
            max-width: 1400px;
            margin: 0 auto;
            padding-left: 20px;
            padding-right: 20px;
        }

        .logo {
            font-size: 24px;
            font-weight: bold;
            color: #25acebb2;
            text-decoration: none;
            flex-shrink: 0;
            display: flex;
            align-items: center;
            gap: 4px;
        }

        .nav-links {
            margin-left: 60px;
            display: flex;
            list-style: none;
            gap: 30px;
            flex-grow: 1;
            justify-content: center;
        }

        .nav-links a {
            text-decoration: none;
            color: #4b5563;
            font-weight: 500;
            transition: color 0.3s ease;
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: #2563eb;
        }

        .auth-buttons {
            display: flex;
            gap: 10px;
            flex-shrink: 0;
        }

        .btn {
            padding: 10px 20px;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-weight: 500;
            transition: all 0.3s ease;
            text-decoration: none;
            display: inline-block;
            text-align: center;
            font-size: 14px;
        }

        .btn-primary {
            background: #2563eb;
            color: white;
        }

        .btn-primary:hover {
            background: #1d4ed8;
            transform: translateY(-2px);
        }

        .btn-secondary {
            background: transparent;
            color: #6b7280;
            border: 2px solid #e5e7eb;
        }

        .btn-secondary:hover {
            background: #f3f4f6;
        }

        /* Hero Section */
        .hero {
            padding: 120px 0 80px;
            text-align: center;
            color: white;
            background-image: url("/NET4CLEANAIR/client/images/sky.jpg"); /* <-- absolute path */
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            position: relative;
        }

        .hero::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(128, 128, 128, 0.4);
            z-index: 1;
        }

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

        .hero h1 {
            font-size: 48px;
            font-weight: 700;
            margin-bottom: 20px;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
        }

        .hero p {
            font-size: 20px;
            margin-bottom: 40px;
            opacity: 0.9;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
            line-height: 1.6;
        }

        /* Main Content */
        .main-content {
            background: white;
            min-height: 100vh;
            padding: 60px 0;
        }

        .content-wrapper {
            max-width: 900px;
            margin: 0 auto;
            padding: 0 20px;
        }

        .content-section {
            margin-bottom: 50px;
        }

        .content-section h2 {
            font-size: 32px;
            color: #1f2937;
            margin-bottom: 20px;
            border-left: 4px solid #2563eb;
            padding-left: 20px;
        }

        .content-section h3 {
            font-size: 24px;
            color: #374151;
            margin-bottom: 15px;
            margin-top: 30px;
        }

        .content-section p {
            font-size: 16px;
            line-height: 1.7;
            color: #4b5563;
            margin-bottom: 15px;
            text-align: justify;
        }

        .highlight-box {
            background: linear-gradient(135deg, #eff6ff 0%, #f0f9ff 100%);
            border-left: 4px solid #2563eb;
            padding: 25px;
            border-radius: 8px;
            margin: 30px 0;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        }

        .highlight-box p {
            margin: 0;
            font-size: 18px;
            font-weight: 500;
            color: #1f2937;
            font-style: italic;
        }

        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 30px;
            margin: 40px 0;
        }

        .stat-card {
            text-align: center;
            padding: 30px 20px;
            background: #f8fafc;
            border-radius: 12px;
            border: 2px solid #e5e7eb;
            transition: all 0.3s ease;
        }

        .stat-card:hover {
            border-color: #2563eb;
            transform: translateY(-5px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }

        .stat-number {
            font-size: 36px;
            font-weight: 700;
            color: #2563eb;
            display: block;
            margin-bottom: 10px;
        }

        .stat-label {
            font-size: 14px;
            color: #6b7280;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }

        .timeline {
            position: relative;
            padding: 20px 0;
        }

        .timeline::before {
            content: '';
            position: absolute;
            left: 50%;
            top: 0;
            bottom: 0;
            width: 2px;
            background: #e5e7eb;
            transform: translateX(-50%);
        }

        .timeline-item {
            position: relative;
            margin-bottom: 30px;
            padding: 0 30px;
        }

        .timeline-item::before {
            content: '';
            position: absolute;
            left: 50%;
            top: 10px;
            width: 12px;
            height: 12px;
            background: #2563eb;
            border-radius: 50%;
            transform: translateX(-50%);
            z-index: 1;
        }

        .timeline-content {
            background: white;
            padding: 20px;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            margin-left: 20px;
        }

        .timeline-date {
            font-weight: 600;
            color: #2563eb;
            font-size: 14px;
            margin-bottom: 5px;
        }

        .timeline-title {
            font-size: 18px;
            font-weight: 600;
            color: #1f2937;
            margin-bottom: 10px;
        }

        .timeline-desc {
            color: #6b7280;
            line-height: 1.6;
        }

        /* Footer */
        .footer {
            background: #1f2937;
            color: white;
            padding: 40px 0;
            text-align: center;
        }

        .footer p {
            color: #9ca3af;
            margin-bottom: 20px;
        }

        .footer-links {
            display: flex;
            justify-content: center;
            gap: 30px;
            margin-bottom: 20px;
        }

        .footer-links a {
            color: #d1d5db;
            text-decoration: none;
            transition: color 0.3s ease;
        }

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

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

            .hero h1 {
                font-size: 32px;
            }

            .hero p {
                font-size: 16px;
            }

            .content-section h2 {
                font-size: 24px;
            }

            .stats-grid {
                grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
                gap: 20px;
            }

            .timeline::before {
                left: 20px;
            }

            .timeline-item {
                padding-left: 50px;
                padding-right: 0;
            }

            .timeline-item::before {
                left: 20px;
                transform: translateX(-50%);
            }

            .timeline-content {
                margin-left: 0;
            }

            .footer-links {
                flex-direction: column;
                gap: 15px;
            }
        }