:root {
    --primary-blue: #2250ff;
    --accent-green: #00ed90;
    --dark-slate: #1e213a;
    --focus-yellow: #ffd400;
    --gray-light: #f5f5f5;
    --gray-medium: #666;
    --gray-dark: #333;
}

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

body {
    font-family: 'Inter', sans-serif;
    font-weight: 400;
    line-height: 1.6;
    color: var(--gray-dark);
}

h1,
h2,
h3 {
    font-weight: 600;
    line-height: 1.2;
}

h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    position: relative;
    top: 0;
    width: 100%;
    background: white;
    border-bottom: 1px solid #e5e5e5;
    z-index: 1000;
    display: flex;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
    flex: 1;
}

nav img {
    margin-top: 8px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-blue);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: var(--gray-dark);
    text-decoration: none;
    transition: color 0.2s;
}

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

/* Hero Section */
.hero {
    padding: 8rem 0 4rem;
    animation: fadeIn 0.08s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: center;
}

.hero-visual {
    position: relative;
}

.globe-icon {
    width: 100%;
    max-width: 300px;
    height: auto;
}

.edge-nodes {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.edge-node {
    position: absolute;
    width: 8px;
    height: 8px;
    background: var(--primary-blue);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }

    50% {
        transform: scale(1.5);
        opacity: 0.5;
    }

    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.hero-text h1 {
    color: var(--dark-slate);
}

.hero-text p {
    font-size: 1.25rem;
    color: var(--gray-medium);
    margin-bottom: 2rem;
}

.url-shortener {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    max-width: 480px;
}

.url-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid #e5e5e5;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

.url-input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(34, 80, 255, 0.1);
}

.btn {
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: inset 0 2px 0 rgba(255, 255, 255, 0.2);
}

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

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(34, 80, 255, 0.3);
}

.btn-cta {
    background: var(--accent-green);
    color: var(--dark-slate);
}

.btn-cta:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 237, 144, 0.3);
}

.hero-features {
    display: flex;
    gap: 1rem;
    font-size: 0.875rem;
    color: var(--gray-medium);
}

.hero-features span::before {
    content: '• ';
}

/* Why shrts section */
.why-shrts {
    padding: 4rem 0;
    background: var(--gray-light);
}

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

.feature-card {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
}

.feature-card p {
    font-size: 0.875rem;
    color: var(--gray-medium);
}

/* How it works */
.how-it-works {
    padding: 4rem 0;
}

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

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

.step::after {
    content: '→';
    position: absolute;
    right: -2rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 2rem;
    color: var(--gray-medium);
}

.step:last-child::after {
    display: none;
}

.step-number {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.step h3 {
    margin-bottom: 0.5rem;
}

.step p {
    color: var(--gray-medium);
}

/* Math section */
.math-section {
    padding: 4rem 0;
    background: var(--gray-light);
}

.math-table {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th,
td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e5e5e5;
}

th {
    font-weight: 600;
    color: var(--dark-slate);
}

.footnote {
    margin-top: 1rem;
    font-size: 0.875rem;
    color: var(--gray-medium);
}

/* Developer section */
.developer-section {
    padding: 4rem 0;
    background: var(--dark-slate);
    color: white;
}

.code-block {
    background: #0d0f1a;
    padding: 2rem;
    border-radius: 8px;
    position: relative;
    overflow-x: auto;
}

code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    color: #a8b2d1;
}

.copy-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    padding: 0.5rem 1rem;
    background: var(--primary-blue);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.75rem;
}

.response {
    margin-top: 1rem;
    color: #64d86b;
}

.dev-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.pill-btn {
    padding: 0.5rem 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    text-decoration: none;
    border-radius: 24px;
    font-size: 0.875rem;
    transition: background 0.2s;
}

.pill-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.pill-btn.disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* CTA section */
.cta-section {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary-blue), #1a3cbf);
    color: white;
    text-align: center;
}

.cta-section h2 {
    margin-bottom: 0.5rem;
}

.cta-section p {
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* Footer */
footer {
    padding: 2rem 0;
    background: var(--dark-slate);
    color: white;
}

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

.footer-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.footer-links a {
    color: white;
    text-decoration: none;
    font-size: 0.875rem;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-links a:hover {
    opacity: 1;
}

/* Mobile styles */
@media (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-visual {
        order: 2;
        max-width: 200px;
        margin: 0 auto;
    }

    .url-shortener {
        flex-direction: column;
        max-width: 100%;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .steps {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .step::after {
        display: none;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
    }

    .footer-links {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        text-align: center;
    }
}

/* Focus styles for accessibility */
*:focus {
    outline: 2px solid var(--focus-yellow);
    outline-offset: 2px;
}