/* Fonts */
@font-face {
    font-family: 'Suisse Intl';
    src: url('assets/fonts/SuisseIntl-Regular.otf') format('opentype');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Suisse Intl';
    src: url('assets/fonts/SuisseIntl-Medium.otf') format('opentype');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Suisse Intl';
    src: url('assets/fonts/SuisseIntl-SemiBold.otf') format('opentype');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

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

:root {
    --black: #000000;
    --white: #ffffff;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-300: #d4d4d4;
    --gray-400: #a3a3a3;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;

    --font-sans: 'Suisse Intl', 'SuisseIntl', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;
    --space-5xl: 8rem;

    --max-width: 1200px;
    --content-width: 720px;
}

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

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--gray-800);
    background: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--black);
}

h1 { font-size: clamp(2.5rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.125rem; }

p {
    color: var(--gray-600);
}

a {
    color: inherit;
    text-decoration: none;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--gray-100);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--space-md) var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 600;
    font-size: 1.125rem;
}

.logo-img {
    width: 32px;
    height: 32px;
    border-radius: 50%;
}

.nav-links {
    display: flex;
    gap: var(--space-xl);
}

.nav-links a {
    font-size: 0.875rem;
    color: var(--gray-600);
    transition: color 0.2s;
}

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

/* Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-5xl) var(--space-xl);
    text-align: center;
}

.hero-content {
    max-width: var(--content-width);
}

.hero-badge {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: var(--gray-100);
    border-radius: 100px;
    font-size: 0.875rem;
    color: var(--gray-600);
    margin-bottom: var(--space-xl);
}

.hero-title {
    margin-bottom: var(--space-lg);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--gray-500);
    margin-bottom: var(--space-2xl);
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    margin-bottom: var(--space-lg);
}

.hero-form {
    display: flex;
    gap: var(--space-sm);
    max-width: 400px;
    margin: 0 auto var(--space-md);
}

.hero-lightpaper {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.9375rem;
    color: var(--gray-500);
    transition: color 0.2s;
}

.hero-lightpaper:hover {
    color: var(--black);
}

.hero-form input {
    flex: 1;
    padding: var(--space-md) var(--space-lg);
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    outline: none;
    transition: border-color 0.2s;
}

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

.hero-form button {
    padding: var(--space-md) var(--space-xl);
    background: var(--black);
    color: var(--white);
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: opacity 0.2s;
}

.hero-form button:hover {
    opacity: 0.85;
}

.hero-note {
    font-size: 0.875rem;
    color: var(--gray-400);
}

/* Sections */
.section {
    padding: var(--space-5xl) var(--space-xl);
}

.section-alt {
    background: var(--gray-50);
}

.section-inner {
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.section-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--gray-400);
    margin-bottom: var(--space-md);
}

.section-header h2 {
    margin-bottom: var(--space-md);
}

.section-desc {
    max-width: 600px;
    margin: 0 auto;
    font-size: 1.125rem;
    color: var(--gray-500);
}

/* Problem Grid */
.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.problem-card {
    padding: var(--space-xl);
    background: var(--white);
    border-radius: 12px;
    border: 1px solid var(--gray-200);
}

.problem-card h3 {
    margin-bottom: var(--space-sm);
}

.problem-card p {
    font-size: 0.9375rem;
}

/* Stack Visual */
.stack-visual {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    max-width: 500px;
    margin: 0 auto;
}

.stack-item {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    padding: var(--space-lg) var(--space-xl);
    background: var(--gray-50);
    border-radius: 12px;
    border: 1px solid var(--gray-200);
}

.stack-item-highlight {
    background: var(--black);
    border-color: var(--black);
}

.stack-item-highlight .stack-icon,
.stack-item-highlight h4,
.stack-item-highlight p {
    color: var(--white);
}

.stack-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--white);
    border-radius: 10px;
    color: var(--black);
    flex-shrink: 0;
}

.stack-item-highlight .stack-icon {
    background: var(--gray-800);
}

.stack-content h4 {
    margin-bottom: var(--space-xs);
}

.stack-content p {
    font-size: 0.875rem;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.feature-card {
    padding: var(--space-xl);
    background: var(--white);
    border-radius: 12px;
    border: 1px solid var(--gray-200);
}

.feature-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--gray-100);
    border-radius: 12px;
    margin-bottom: var(--space-lg);
    color: var(--black);
}

.feature-card h3 {
    margin-bottom: var(--space-sm);
}

.feature-card p {
    font-size: 0.9375rem;
    line-height: 1.7;
}

/* Vision */
.vision-layout {
    max-width: 640px;
    margin: 0 auto;
}

.vision-content h2 {
    margin-bottom: var(--space-2xl);
}

.vision-points {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.vision-point {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
}

.vision-check {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--gray-100);
    border-radius: 50%;
    flex-shrink: 0;
    color: var(--black);
}

.vision-point p {
    font-size: 1.0625rem;
    color: var(--gray-700);
    padding-top: 2px;
}

/* Developer Benefits */
.dev-benefits {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-2xl);
    margin-bottom: var(--space-3xl);
}

.dev-benefit {
    position: relative;
}

.dev-benefit-number {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--gray-300);
    margin-bottom: var(--space-sm);
}

.dev-benefit h4 {
    margin-bottom: var(--space-sm);
}

.dev-benefit p {
    font-size: 0.9375rem;
}

/* Code Example */
.code-example {
    background: var(--gray-900);
    border-radius: 12px;
    overflow: hidden;
    max-width: 640px;
    margin: 0 auto;
}

.code-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    background: var(--gray-800);
}

.code-dot {
    width: 12px;
    height: 12px;
    background: var(--gray-600);
    border-radius: 50%;
}

.code-title {
    margin-left: auto;
    font-size: 0.75rem;
    color: var(--gray-500);
}

.code-example pre {
    padding: var(--space-xl);
    overflow-x: auto;
}

.code-example code {
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
    font-size: 0.875rem;
    line-height: 1.8;
    color: var(--gray-300);
}

.code-comment { color: var(--gray-500); }
.code-keyword { color: #93c5fd; }
.code-string { color: #86efac; }
.code-prop { color: #fcd34d; }
.code-number { color: #f9a8d4; }

/* Timeline */
.timeline {
    max-width: 500px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 11px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gray-200);
}

.timeline-item {
    display: flex;
    gap: var(--space-lg);
    position: relative;
}

.timeline-marker {
    width: 24px;
    height: 24px;
    background: var(--white);
    border: 2px solid var(--gray-300);
    border-radius: 50%;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
}

.timeline-marker-done {
    background: var(--black);
    border-color: var(--black);
}

.timeline-date {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-400);
    margin-bottom: var(--space-xs);
}

.timeline-content h4 {
    margin-bottom: var(--space-xs);
}

.timeline-content p {
    font-size: 0.9375rem;
}

/* CTA Section */
.section-cta {
    background: var(--black);
    text-align: center;
}

.cta-content h2 {
    color: var(--white);
    margin-bottom: var(--space-md);
}

.cta-content > p {
    color: var(--gray-400);
    margin-bottom: var(--space-2xl);
}

.cta-form {
    display: flex;
    gap: var(--space-sm);
    max-width: 400px;
    margin: 0 auto;
}

.cta-form input {
    flex: 1;
    padding: var(--space-md) var(--space-lg);
    background: var(--gray-800);
    border: 1px solid var(--gray-700);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    color: var(--white);
    outline: none;
    transition: border-color 0.2s;
}

.cta-form input::placeholder {
    color: var(--gray-500);
}

.cta-form input:focus {
    border-color: var(--gray-500);
}

.cta-form button {
    padding: var(--space-md) var(--space-xl);
    background: var(--white);
    color: var(--black);
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: opacity 0.2s;
}

.cta-form button:hover {
    opacity: 0.9;
}

/* Footer */
.footer {
    padding: var(--space-3xl) var(--space-xl);
    border-top: 1px solid var(--gray-200);
}

.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-xl);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 600;
}

.footer-logo {
    width: 24px;
    height: 24px;
    border-radius: 50%;
}

.footer-links {
    display: flex;
    gap: var(--space-xl);
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--gray-500);
    transition: color 0.2s;
}

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

.footer-copy p {
    font-size: 0.875rem;
    color: var(--gray-400);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero {
        padding: var(--space-4xl) var(--space-lg);
    }

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

    .section {
        padding: var(--space-3xl) var(--space-lg);
    }

    .cta-form {
        flex-direction: column;
    }

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

/* Animation */
@media (prefers-reduced-motion: no-preference) {
    .hero-content,
    .section-header,
    .problem-card,
    .feature-card,
    .vision-point,
    .dev-benefit,
    .timeline-item {
        animation: fadeInUp 0.6s ease-out both;
    }

    .problem-card:nth-child(1) { animation-delay: 0.1s; }
    .problem-card:nth-child(2) { animation-delay: 0.2s; }
    .problem-card:nth-child(3) { animation-delay: 0.3s; }

    .feature-card:nth-child(1) { animation-delay: 0.1s; }
    .feature-card:nth-child(2) { animation-delay: 0.2s; }
    .feature-card:nth-child(3) { animation-delay: 0.3s; }
    .feature-card:nth-child(4) { animation-delay: 0.4s; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}