:root {
    --color-black: #000000;
    --color-white: #ffffff;
    --color-grey: #878787;
    --color-light-grey: #f3f4f6;
    
    --border-standard: 1px solid var(--color-black);
    --border-radius: 0px; /* Sharp corners */
    
    --font-primary: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--color-white);
    color: var(--color-black);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 900;
    line-height: 1.1;
    letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); margin-bottom: var(--spacing-sm); }
h2 { font-size: clamp(1.25rem, 3vw, 1.75rem); font-weight: 400; color: var(--color-grey); margin-bottom: var(--spacing-md); }
h3 { font-size: clamp(2rem, 4vw, 3rem); margin-bottom: var(--spacing-md); }
h4 { font-size: 1.25rem; margin-bottom: var(--spacing-sm); }
p { font-size: 1.125rem; }

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

.border-top { border-top: var(--border-standard); }
.border-bottom { border-bottom: var(--border-standard); }

/* Components */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-weight: 700;
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: all 0.1s linear; /* Very fast, linear transitions as per guidelines */
    cursor: pointer;
    font-size: 1rem;
}

.btn-solid {
    background-color: var(--color-black);
    color: var(--color-white);
    border: var(--border-standard);
}

.btn-solid:hover {
    background-color: var(--color-white);
    color: var(--color-black);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-black);
    border: var(--border-standard);
}

.btn-outline:hover {
    background-color: var(--color-black);
    color: var(--color-white);
}

.btn-link {
    background-color: transparent;
    color: var(--color-black);
    text-decoration: underline;
    text-underline-offset: 4px;
    padding: 0.75rem 0;
}

.btn-link:hover {
    color: var(--color-grey);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.25rem;
}

/* Header & Nav */
header {
    border-bottom: var(--border-standard);
    position: sticky;
    top: 0;
    background-color: var(--color-white);
    z-index: 100;
}

.nav-container {
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 900;
    font-size: 1.5rem;
    letter-spacing: -0.05em;
    text-transform: uppercase;
}

.logo-icon {
    height: 1.5rem;
    width: auto;
}

nav {
    display: flex;
    gap: var(--spacing-md);
}

nav a {
    color: var(--color-black);
    text-decoration: none;
    font-weight: 700;
    transition: color 0.1s linear;
}

nav a:hover {
    color: var(--color-grey);
}

/* Hero Section */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    align-items: center;
    padding-top: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    align-items: center;
    margin-top: var(--spacing-lg);
}

.hero-visual {
    width: 100%;
    aspect-ratio: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-visual img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    mix-blend-mode: multiply;
}

/* Social Proof Marquee */
.social-proof {
    overflow: hidden;
    background-color: var(--color-light-grey);
}

.marquee-container {
    padding-top: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.marquee-container p {
    font-weight: 700;
    font-size: 0.875rem;
    color: var(--color-grey);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.marquee {
    width: 100%;
    overflow: hidden;
    position: relative;
    white-space: nowrap;
}

.marquee-content {
    display: inline-block;
    animation: marquee 20s linear infinite;
}

.marquee-content span {
    font-weight: 900;
    font-size: 1.5rem;
    margin: 0 var(--spacing-md);
    color: var(--color-black);
    opacity: 0.8;
}

@keyframes marquee {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* Solo Dev Banner */
.solo-dev-banner {
    background-color: var(--color-light-grey);
    text-align: center;
}

.solo-dev-banner .container {
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
}

.solo-dev-banner p {
    font-weight: 700;
    font-size: 0.875rem;
    color: var(--color-grey);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Problem vs Solution */
.split-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
}

.border-left {
    border-left: var(--border-standard);
}

.column {
    padding: var(--spacing-xl) var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.img-wrapper {
    width: 100%;
    max-width: 400px;
    margin-top: var(--spacing-md);
}

.img-wrapper img {
    width: 100%;
    height: auto;
    border: var(--border-standard);
}

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

.card {
    border: var(--border-standard);
    padding: var(--spacing-md);
    transition: transform 0.1s linear, box-shadow 0.1s linear;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 4px 4px 0 var(--color-black);
}

/* How It Works */
.steps-list {
    display: flex;
    flex-direction: column;
}

.step {
    padding: var(--spacing-md) 0;
    display: grid;
    grid-template-columns: 300px 1fr;
    align-items: baseline;
    gap: var(--spacing-md);
}

.step-num {
    font-size: 2rem;
    font-weight: 900;
}

.step p {
    font-size: 1.5rem;
}

/* Testimonials */
.testimonials {
    display: flex;
    justify-content: center;
}

.testimonial-card {
    border: var(--border-standard);
    padding: var(--spacing-lg);
    max-width: 800px;
    text-align: center;
}

.testimonial-card p {
    font-size: 2rem;
    font-weight: 700;
    font-style: italic;
    margin-bottom: var(--spacing-md);
}

.testimonial-card cite {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-grey);
    font-style: normal;
}

/* Final CTA */
.final-cta {
    text-align: center;
    padding-top: var(--spacing-xl);
    padding-bottom: var(--spacing-xl);
}

.final-cta-content {
    max-width: 600px;
    margin: 0 auto;
}

.final-cta p {
    margin-bottom: var(--spacing-lg);
    color: var(--color-grey);
}

/* Footer */
footer {
    background-color: var(--color-white);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-md);
    padding-bottom: var(--spacing-md);
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
}

.footer-links a {
    color: var(--color-grey);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 700;
}

.footer-links a:hover {
    color: var(--color-black);
}

footer p {
    font-size: 0.875rem;
    color: var(--color-grey);
}

/* Responsive */
@media (max-width: 900px) {
    .container {
        padding-top: var(--spacing-md);
        padding-bottom: var(--spacing-md);
    }
    
    .nav-container {
        padding-top: var(--spacing-sm);
        padding-bottom: var(--spacing-sm);
    }

    .solo-dev-banner .container {
        padding-top: var(--spacing-sm);
        padding-bottom: var(--spacing-sm);
    }

    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        gap: var(--spacing-md);
    }
    
    .hero-cta {
        justify-content: center;
    }

    .hero-visual {
        max-width: 500px;
        margin: 0 auto;
    }

    .split-layout {
        grid-template-columns: 1fr;
    }
    
    .border-left {
        border-left: none;
        border-top: var(--border-standard);
    }

    .column {
        padding: var(--spacing-md);
    }
    
    .grid-3 {
        grid-template-columns: 1fr;
    }

    .step {
        grid-template-columns: 1fr;
        gap: var(--spacing-xs);
    }
    
    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }
    
    nav {
        display: none; /* simple mobile nav hide for now */
    }
}

@media (max-width: 600px) {
    .container {
        padding-left: var(--spacing-sm);
        padding-right: var(--spacing-sm);
    }

    .nav-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .hero-cta {
        flex-direction: column;
        width: 100%;
        gap: var(--spacing-sm);
    }

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

    .step-num {
        font-size: 1.5rem;
    }

    .step p {
        font-size: 1.125rem;
    }

    .logo {
        font-size: 1.25rem;
    }
    
    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }
}