/* 
 * PULSE STUDIO - Style Guide & CSS Framework
 * Design: High-end Modern Fitness Studio
 */

:root {
    /* Color Palette */
    --primary: #A3E635;
    --primary-hover: #bef264;
    --bg-dark: #000000;
    --bg-surface: #121212;
    --bg-card: #1C1C1C;
    --text-main: #FFFFFF;
    --text-muted: #A1A1AA;
    --border: #27272A;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-weight-bold: 700;
    --font-weight-extra-bold: 800;
    
    /* Spacing & Sizing */
    --section-padding: 100px;
    --container-max-width: 1200px;
    --border-radius: 4px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 1. Global Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-family);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

ul {
    list-style: none;
}

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

/* 2. Typography */
h1, h2, h3, h4 {
    text-transform: uppercase;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

h1 {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: var(--font-weight-extra-bold);
}

h2 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: var(--font-weight-bold);
}

h3 {
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
}

p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.text-highlight {
    color: var(--primary);
}

.uppercase-label {
    text-transform: uppercase;
    letter-spacing: 0.2em;
    font-size: 0.875rem;
    color: var(--primary);
    display: block;
    margin-bottom: 1rem;
}

/* 3. Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-weight: var(--font-weight-bold);
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: var(--transition);
    border-radius: var(--border-radius);
    border: 2px solid transparent;
}

.btn-primary {
    background-color: var(--primary);
    color: var(--bg-dark);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(163, 230, 53, 0.2);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--text-main);
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: var(--text-main);
    color: var(--bg-dark);
}

/* 4. Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 1.5rem 0;
    transition: var(--transition);
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 5%;
}

.logo {
    font-size: 1.5rem;
    font-weight: var(--font-weight-extra-bold);
    letter-spacing: 0.1em;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
}

.nav-links a:hover {
    color: var(--primary);
}

/* 5. Grid & Layout Components */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: var(--section-padding) 0;
}

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

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 4rem;
    align-items: center;
}

/* 6. Cards */
.card {
    background: var(--bg-card);
    padding: 3rem 2rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
    border: 1px solid var(--border);
    height: 100%;
}

.card:hover {
    border-color: var(--primary);
    transform: translateY(-10px);
}

.card-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 1.5rem;
    color: var(--primary);
}

/* 7. Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-input {
    width: 100%;
    padding: 1rem 1.5rem;
    background: var(--bg-surface);
    border: 1px solid var(--border);
    color: var(--text-main);
    border-radius: var(--border-radius);
    outline: none;
    transition: var(--transition);
}

.form-input:focus {
    border-color: var(--primary);
}

/* 8. Utility Classes */
.text-center { text-align: center; }
.full-width { width: 100%; }
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.bg-primary-block { background-color: var(--primary); color: var(--bg-dark); }
.glass-effect { backdrop-filter: blur(10px); background: rgba(28, 28, 28, 0.7); }

/* 9. Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.reveal {
    animation: fadeInUp 0.8s ease forwards;
}

/* 10. Footer */
.footer {
    padding: 4rem 0 2rem;
    border-top: 1px solid var(--border);
    background: var(--bg-dark);
}

.footer-bottom {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* 11. Responsive Design */

/* Tablet (1024px) */
@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
    
    .grid-3 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .grid-2 {
        gap: 2rem;
    }
}

/* Mobile (768px) */
@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }

    .nav-links {
        display: none; /* In real project, use a hamburger menu */
    }

    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }

    .header .container {
        padding: 0 1.5rem;
    }

    h1 {
        font-size: 3rem;
    }

    .section {
        padding: 4rem 0;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .btn {
        width: 100%;
        margin-bottom: 1rem;
    }
}

/* Special High-Energy CTA Section */
.cta-banner {
    background-color: var(--primary);
    color: var(--bg-dark);
    padding: 5rem 0;
    text-align: center;
}

.cta-banner h2 {
    color: var(--bg-dark);
    margin-bottom: 2rem;
}

.cta-banner .btn-outline {
    border-color: var(--bg-dark);
    color: var(--bg-dark);
}

.cta-banner .btn-outline:hover {
    background-color: var(--bg-dark);
    color: var(--primary);
}