/* ===================================
   FlowAnalyzer.io Stylesheet
   Professional Water Network Analysis
   =================================== */

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

:root {
    /* Colors */
    --primary: #1976D2;
    --primary-dark: #1565C0;
    --secondary: #00695C;
    --accent: #FF9800;
    --text-dark: #1a1a1a;
    --text-light: #666;
    --bg-light: #f8f9fa;
    --white: #ffffff;
    --gradient: linear-gradient(135deg, #1976D2 0%, #00695C 100%);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-light);
}

.lead {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--text-dark);
}

.small {
    font-size: 0.875rem;
}

/* Gradient Text */
.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-download {
    background: var(--text-dark);
    color: var(--white);
    width: 100%;
    justify-content: center;
}

.btn-download:hover {
    background: var(--primary);
}

.btn-arrow {
    transition: transform 0.3s ease;
}

.btn:hover .btn-arrow {
    transform: translateX(4px);
}

/* Navigation */
.navbar {
    background: var(--white);
    padding: 1.5rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
}

.logo {
    font-size: 2rem;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-light);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.nav-mobile {
    display: none;
}

.menu-toggle {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-dark);
}

.mobile-menu {
    display: none;
    background: var(--white);
    padding: 1rem;
    box-shadow: var(--shadow-md);
    position: fixed;
    top: 80px;
    left: 0;
    right: 0;
    z-index: 999;
}

.mobile-menu a {
    display: block;
    padding: 1rem;
    text-decoration: none;
    color: var(--text-dark);
    border-bottom: 1px solid var(--bg-light);
}

.mobile-menu.active {
    display: block;
}

/* Hero Section */
.hero {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #e8f4f8 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.hero-title {
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.hero-badges {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.badge {
    padding: 0.5rem 1rem;
    background: var(--white);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.app-mockup {
    position: relative;
}

.mockup-placeholder {
    background: var(--gradient);
    color: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    font-size: 4rem;
    box-shadow: var(--shadow-lg);
}

.mockup-placeholder p {
    font-size: 1rem;
    margin-top: var(--spacing-sm);
    color: var(--white);
}

/* Features Section */
.features {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-header h2 {
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.25rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.feature-card {
    background: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

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

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.feature-card h3 {
    color: var(--text-dark);
    margin-bottom: var(--spacing-xs);
}

.feature-card p {
    color: var(--text-light);
}

/* About Section */
.about {
    padding: var(--spacing-xl) 0;
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.about-text h2 {
    margin-bottom: var(--spacing-md);
}

.stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.stat {
    text-align: center;
    padding: var(--spacing-sm);
    background: var(--white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-light);
}

.image-placeholder {
    background: var(--gradient);
    color: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    font-size: 4rem;
    box-shadow: var(--shadow-lg);
}

.image-placeholder p {
    font-size: 1rem;
    margin-top: var(--spacing-sm);
    color: var(--white);
}

/* Download Section */
.download {
    padding: var(--spacing-xl) 0;
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.download-card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    text-align: center;
}

.download-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-sm);
}

.download-card h3 {
    margin-bottom: var(--spacing-xs);
}

.download-card .version {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.coming-soon {
    margin-top: var(--spacing-sm);
    color: var(--accent);
    font-weight: 600;
}

.compatibility {
    background: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    text-align: center;
}

.compatibility h4 {
    margin-bottom: var(--spacing-sm);
}

.compatibility ul {
    list-style: none;
    display: inline-block;
    text-align: left;
}

.compatibility li {
    padding: 0.25rem 0;
    color: var(--text-light);
}

/* Contact Section */
.contact {
    padding: var(--spacing-xl) 0;
    background: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.contact-item {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
}

.contact-icon {
    font-size: 2rem;
}

.contact-item h4 {
    margin-bottom: 0.25rem;
}

.contact-item a {
    color: var(--primary);
    text-decoration: none;
}

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

.contact-form {
    background: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: var(--spacing-sm);
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: var(--radius-sm);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: var(--white);
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: rgba(255,255,255,0.7);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
}

.footer-column h4 {
    margin-bottom: var(--spacing-sm);
    color: var(--white);
}

.footer-column a {
    display: block;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    margin-bottom: 0.5rem;
    transition: color 0.3s ease;
}

.footer-column a:hover {
    color: var(--white);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.footer-credits p {
    color: rgba(255,255,255,0.7);
    margin-bottom: 0.25rem;
}

.footer-credits .disclaimer {
    font-size: 0.875rem;
    max-width: 600px;
}

.footer-copyright p {
    color: rgba(255,255,255,0.5);
    font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 968px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }

    .nav-links {
        display: none;
    }

    .nav-mobile {
        display: block;
    }

    .hero .container {
        grid-template-columns: 1fr;
    }

    .hero-image {
        order: -1;
    }

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

    .download-cards {
        grid-template-columns: 1fr;
    }

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

    .footer-content {
        grid-template-columns: 1fr;
    }

    .footer-links {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

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

@media (max-width: 640px) {
    :root {
        --spacing-lg: 3rem;
        --spacing-xl: 4rem;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }

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

    .btn {
        width: 100%;
        justify-content: center;
    }

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