:root {
            --primary-color: #E50914; /* Energetic Red */
            --secondary-color: #FFFFFF; /* White */
            --dark-color: #141414; /* Dark Background */
            --dark-gray: #1d1d1d;
            --light-gray: #8c8c8c;
        }

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

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: 'Poppins', sans-serif;
            background-color: var(--dark-color);
            color: var(--secondary-color);
            line-height: 1.6;
            overflow-x: hidden;
        }

        /* --- Global Styles --- */
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 2rem;
        }

        h1, h2 {
            font-weight: 700;
            line-height: 1.2;
        }
        
        h1 {
            font-size: 4rem;
            font-weight: 900;
        }

        h2 {
            font-size: 2.5rem;
            text-align: center;
            margin-bottom: 3rem;
            text-transform: uppercase;
            letter-spacing: 2px;
            position: relative;
        }
        
        h2::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background-color: var(--primary-color);
        }

        section {
            padding: 6rem 0;
        }

        .btn {
            display: inline-block;
            padding: 0.8rem 2.5rem;
            background: var(--primary-color);
            color: var(--secondary-color);
            text-decoration: none;
            border: none;
            border-radius: 5px;
            font-weight: 600;
            font-size: 1rem;
            cursor: pointer;
            transition: transform 0.3s ease, background-color 0.3s ease;
        }
        
        .btn:hover {
            transform: scale(1.05);
            background-color: #ff0a16;
        }

        /* --- Header & Navigation --- */
        .header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            padding: 1.5rem 0;
            z-index: 1000;
            transition: background-color 0.4s ease, padding 0.4s ease;
        }

        .header.scrolled {
            background-color: rgba(20, 20, 20, 0.95);
            padding: 1rem 0;
            box-shadow: 0 2px 10px rgba(0,0,0,0.5);
        }
        
        .navbar {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .logo {
            font-size: 1.8rem;
            font-weight: 900;
            color: var(--primary-color);
            text-decoration: none;
        }

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

        .nav-links li {
            margin-left: 2rem;
        }

        .nav-links a {
            color: var(--secondary-color);
            text-decoration: none;
            font-weight: 600;
            position: relative;
            padding-bottom: 5px;
        }
        
        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--primary-color);
            transition: width 0.3s ease;
        }

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

        /* --- Hero Section --- */
        #hero {
            height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            position: relative;
            padding: 0 2rem;
            background-image: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1571902943202-507ec2618e8f?ixlib=rb-4.0.3&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1975&q=80');
            background-size: cover;
            background-position: center center;
            background-attachment: fixed;
        }
        
        .hero-content h1 {
            margin-bottom: 1.5rem;
            text-shadow: 0 0 20px rgba(0,0,0,0.8);
        }
        .hero-content p {
            font-size: 1.2rem;
            max-width: 600px;
            margin: 0 auto 2rem;
            font-weight: 300;
        }

        /* --- About Section --- */
        .about-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 4rem;
            align-items: center;
        }
        
        .about-image img {
            width: 100%;
            height: auto;
            border-radius: 10px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.5);
        }

        .about-content h3 {
            color: var(--primary-color);
            font-size: 1.5rem;
            margin-bottom: 1rem;
        }
        
        .about-content p {
            color: var(--light-gray);
            margin-bottom: 1rem;
        }

        /* --- Services Section --- */
        #services {
            background-color: var(--dark-gray);
        }
        .services-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
        }
        .service-card {
            background: var(--dark-color);
            padding: 2.5rem 2rem;
            border-radius: 10px;
            text-align: center;
            border: 1px solid #222;
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        .service-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.7);
        }
        .service-card .icon {
            font-size: 3rem;
            color: var(--primary-color);
            margin-bottom: 1.5rem;
        }
        .service-card h3 {
            font-size: 1.5rem;
            margin-bottom: 1rem;
        }
        .service-card p {
            color: var(--light-gray);
        }

        /* --- Trainers Section --- */
        .trainers-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            perspective: 1000px;
        }

        .trainer-card {
            position: relative;
            width: 100%;
            height: 400px;
            cursor: pointer;
        }

        .trainer-card-inner {
            position: relative;
            width: 100%;
            height: 100%;
            transform-style: preserve-3d;
            transition: transform 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }

        .trainer-card:hover .trainer-card-inner {
            transform: rotateY(180deg);
        }

        .trainer-card-front, .trainer-card-back {
            position: absolute;
            width: 100%;
            height: 100%;
            backface-visibility: hidden;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 10px 30px rgba(0,0,0,0.5);
        }
        
        .trainer-card-front img {
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .trainer-card-front .trainer-name {
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            padding: 1.5rem;
            background: linear-gradient(to top, rgba(0,0,0,0.9), transparent);
        }
        
        .trainer-name h3 {
            font-size: 1.5rem;
            margin: 0;
        }

        .trainer-card-back {
            background: var(--dark-gray);
            transform: rotateY(180deg);
            padding: 2rem;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            text-align: center;
        }

        .trainer-card-back h3 {
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        
        .trainer-card-back p {
            color: var(--light-gray);
            font-size: 0.9rem;
        }

        /* --- Testimonials Section --- */
        #testimonials {
            background-color: var(--dark-gray);
        }
        .testimonial-card {
            background: var(--dark-color);
            padding: 2rem;
            border-radius: 10px;
            border-left: 5px solid var(--primary-color);
            margin-bottom: 2rem;
            max-width: 800px;
            margin-left: auto;
            margin-right: auto;
        }
        .testimonial-card p {
            font-style: italic;
            color: var(--light-gray);
            margin-bottom: 1rem;
        }
        .testimonial-author {
            font-weight: 700;
            text-align: right;
            color: var(--secondary-color);
        }

        /* --- Contact Section --- */
        .contact-form {
            max-width: 700px;
            margin: 0 auto;
        }
        .form-group {
            margin-bottom: 1.5rem;
        }
        .form-group input, .form-group textarea {
            width: 100%;
            padding: 0.8rem;
            background: var(--dark-gray);
            border: 1px solid #333;
            border-radius: 5px;
            color: var(--secondary-color);
            font-family: 'Poppins', sans-serif;
        }
        
        .form-group input:focus, .form-group textarea:focus {
            outline: none;
            border-color: var(--primary-color);
        }
        
        .contact-form .btn {
            width: 100%;
            font-size: 1.2rem;
        }
        
        /* --- Footer --- */
        .footer {
            background-color: #000;
            text-align: center;
            padding: 2rem 0;
            color: var(--light-gray);
        }

        /* --- Mobile Responsiveness --- */
        @media (max-width: 768px) {
            h1 { font-size: 2.8rem; }
            h2 { font-size: 2rem; }

            .nav-links { display: none; /* Simplification for this example */ }
            
            .about-grid { grid-template-columns: 1fr; }
            .about-image { margin-bottom: 2rem; }

            section { padding: 4rem 0; }
        }