/* ===================================
   CSS Variables & Reset
   =================================== */

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --background: #ffffff;
    --background-light: #f9fafb;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --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);
    --transition: all 0.3s ease;
}

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

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--background);
}

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

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

ul {
    list-style: none;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h2 {
    font-size: 2.5rem;
    color: var(--text-dark);
}

h3 {
    font-size: 1.75rem;
}

p {
    margin-bottom: 1rem;
    color: var(--text-light);
    font-size: 1.125rem;
}

/* ===================================
   Utility Classes
   =================================== */

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

.section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-top: -0.5rem;
}

/* ===================================
   Buttons
   =================================== */

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 0.5rem;
    border: 2px solid transparent;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* ===================================
   Navigation
   =================================== */

.navbar {
    background-color: var(--background);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.logo {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
}

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

.btn-nav {
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: white !important;
    border-radius: 0.5rem;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 0.25rem;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 8rem 0 6rem;
    position: relative;
    overflow: hidden;
}

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

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.375rem;
    margin-bottom: 2.5rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    color: rgba(255, 255, 255, 0.95);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-buttons .btn-primary {
    background-color: white;
    color: var(--primary-color);
}

.hero-buttons .btn-primary:hover {
    background-color: rgba(255, 255, 255, 0.9);
}

.hero-buttons .btn-secondary {
    border-color: white;
    color: white;
}

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

.hero-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    line-height: 0;
}

.hero-wave svg {
    position: relative;
    display: block;
    width: calc(100% + 1.3px);
    height: 60px;
}

.hero-wave path {
    fill: var(--background);
}

/* ===================================
   About Section
   =================================== */

.about {
    background-color: var(--background);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature {
    text-align: center;
    padding: 2rem;
    background-color: var(--background-light);
    border-radius: 1rem;
    transition: var(--transition);
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature h3 {
    font-size: 1.375rem;
    color: var(--text-dark);
    margin-bottom: 0.75rem;
}

.feature p {
    font-size: 1rem;
    color: var(--text-light);
}

/* ===================================
   How It Works Section
   =================================== */

.how-it-works {
    background-color: var(--background-light);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.step {
    text-align: center;
    position: relative;
}

.step-number {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    margin: 0 auto 1.5rem;
}

.step h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.step p {
    font-size: 1rem;
    color: var(--text-light);
}

/* ===================================
   Join Section
   =================================== */

.join {
    background-color: var(--background);
}

.join-groups {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.join-card {
    background-color: var(--background-light);
    padding: 3rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.join-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.join-card h3 {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
}

.join-card p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    line-height: 1.7;
}

/* ===================================
   Contact Section
   =================================== */

.contact {
    background-color: var(--background-light);
}

.contact-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.contact-info h3 {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.contact-details {
    margin-top: 2rem;
}

.contact-item {
    margin-bottom: 1.5rem;
}

.contact-item strong {
    display: block;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.contact-item p {
    color: var(--text-light);
    margin: 0;
}

.contact-item a {
    color: var(--primary-color);
}

.contact-item a:hover {
    text-decoration: underline;
}

.contact-form-container {
    background-color: var(--background);
    padding: 2.5rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-md);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.875rem;
    border: 2px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
}

.form-status {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 0.5rem;
    display: none;
}

.form-status.success {
    background-color: #d1fae5;
    color: #065f46;
    display: block;
}

.form-status.error {
    background-color: #fee2e2;
    color: #991b1b;
    display: block;
}

/* ===================================
   Footer
   =================================== */

.footer {
    background-color: var(--text-dark);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    color: white;
    margin-bottom: 1rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1rem;
}

.footer-section ul {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
    margin: 0;
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--background);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 2rem 0;
        gap: 1rem;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.125rem;
    }

    h2 {
        font-size: 2rem;
    }

    .section {
        padding: 3rem 0;
    }

    .features,
    .steps,
    .join-groups {
        gap: 1.5rem;
    }

    .join-card {
        padding: 2rem;
    }

    .contact-form-container {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero {
        padding: 5rem 0 4rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

    .hero-buttons .btn {
        width: 100%;
    }

    .btn {
        padding: 0.75rem 1.5rem;
    }
}

/* ===================================
   Accessibility
   =================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

:focus-visible {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}