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

:root {
    --bitcoin-orange: #F7931A;
    --text-primary: #1a1a1a;
    --text-secondary: #4a4a4a;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --border-color: #e0e0e0;
    --max-width: 800px;
    --spacing: 2rem;
}

/* Dark mode variables - automatic detection via prefers-color-scheme */
@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #e0e0e0;
        --text-secondary: #b0b0b0;
        --bg-primary: #1a1a1a;
        --bg-secondary: #2a2a2a;
        --border-color: #404040;
    }
}

body {
    font-family: Georgia, "Times New Roman", serif;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

h1, h2, h3, h4, h5, h6 {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-weight: 600;
    line-height: 1.3;
    margin-top: 0;
}

h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    margin-bottom: 1rem;
}

h2 {
    font-size: clamp(1.5rem, 4vw, 2.25rem);
    margin-bottom: 1rem;
    margin-top: 2rem;
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

h4 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    margin-top: 1.25rem;
}

h4.subheading {
    font-size: 1.125rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    padding: 4rem 0;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.hero .logo {
    width: 60%;
    max-width: 400px;
    height: auto;
    margin-bottom: 2rem;
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.hero a {
    display: block;
    text-decoration: none;
}

.hero h2 {
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1rem;
}

.hero .tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.btn {
    display: inline-block;
    padding: 0.875rem 1.75rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s ease;
    border: 2px solid transparent;
    font-size: 1rem;
    min-width: 160px;
    text-align: center;
}

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

.btn-primary:hover,
.btn-primary:focus {
    background-color: #e8840a;
    border-color: #e8840a;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(247, 147, 26, 0.3);
}

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

.btn-secondary:hover,
.btn-secondary:focus {
    background-color: var(--bitcoin-orange);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(247, 147, 26, 0.2);
}

/* Value Props */
.value-props {
    padding: 4rem 0;
    background-color: var(--bg-primary);
}

.value-props h2 {
    text-align: center;
    margin-bottom: 3rem;
}

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

.column {
    padding: 1.5rem;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

.column h3 {
    color: var(--bitcoin-orange);
    margin-bottom: 1rem;
}

.column p {
    color: var(--text-secondary);
}

/* Coming Soon */
.coming-soon {
    padding: 4rem 0;
    background-color: var(--bg-secondary);
    text-align: center;
}

.coming-soon h2 {
    margin-bottom: 1rem;
}

.coming-soon p {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.updates {
    margin-top: 1rem;
    font-style: italic;
    color: var(--text-secondary);
}

/* Footer */
footer {
    padding: 3rem 0;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    text-align: center;
}

footer nav {
    margin-bottom: 1rem;
}

footer nav a {
    color: var(--bitcoin-orange);
    text-decoration: none;
    margin: 0 1rem;
    font-weight: 500;
}

footer nav a:hover,
footer nav a:focus {
    text-decoration: underline;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0.5rem 0;
}

.copyright {
    margin-top: 1rem;
    font-size: 0.85rem;
}

/* Whitepaper Styles */
.whitepaper-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 2rem var(--spacing);
}

.whitepaper-header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.whitepaper-header .logo {
    width: 40%;
    max-width: 300px;
    margin-bottom: 1.5rem;
}

.whitepaper-header a {
    display: inline-block;
    text-decoration: none;
}

.whitepaper-header h2 {
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1rem;
    margin-top: 1rem;
}

.whitepaper-header .tagline {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.download-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

.toc {
    background-color: var(--bg-secondary);
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 3rem;
}

.toc h2 {
    margin-top: 0;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.toc ol {
    list-style: none;
    padding-left: 0;
}

.toc li {
    margin: 0.5rem 0;
}

.toc a {
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.2s;
}

.toc a:hover,
.toc a:focus {
    color: var(--bitcoin-orange);
    text-decoration: underline;
}

.whitepaper-content {
    font-size: 1.125rem;
    line-height: 1.8;
}

.whitepaper-content p {
    margin-bottom: 1.25rem;
}

.whitepaper-content ul,
.whitepaper-content ol {
    margin-bottom: 1.25rem;
    padding-left: 2rem;
}

.whitepaper-content li {
    margin-bottom: 0.5rem;
}

.whitepaper-content strong {
    font-weight: 600;
    color: var(--text-primary);
}

.whitepaper-content em {
    font-style: italic;
}

.whitepaper-content img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 2rem auto;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: filter 0.3s ease;
}

.whitepaper-content figure {
    margin: 2rem 0;
    text-align: center;
}

.whitepaper-content figure img {
    margin-bottom: 0.5rem;
}

/* Dark mode: Add white background to images and gray card background to figures */
@media (prefers-color-scheme: dark) {
    .whitepaper-content img {
        background-color: #ffffff;
        padding: 0.75rem;
        border-radius: 6px;
    }

    .whitepaper-content figure {
        background-color: rgba(255, 255, 255, 0.15);
        padding: 1.5rem;
        border-radius: 8px;
    }
}


.whitepaper-content figcaption {
    font-style: italic;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: 0.5rem;
}

.whitepaper-content code {
    font-family: "Courier New", Courier, monospace;
    font-size: 0.9em;
    background-color: var(--bg-secondary);
    padding: 0.2em 0.4em;
    border-radius: 3px;
}

.whitepaper-content pre {
    background-color: var(--bg-secondary);
    padding: 1rem;
    border-radius: 4px;
    overflow-x: auto;
    margin: 1.5rem 0;
}

.whitepaper-content pre code {
    background: none;
    padding: 0;
}

.whitepaper-content blockquote {
    border-left: 4px solid var(--bitcoin-orange);
    padding-left: 1.5rem;
    margin: 1.5rem 0;
    color: var(--text-secondary);
    font-style: italic;
}

.whitepaper-content hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 2rem 0;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background-color: var(--bitcoin-orange);
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
    z-index: 1000;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: #e8840a;
    transform: translateY(-2px);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    :root {
        --spacing: 1rem;
    }

    .hero {
        padding: 2rem 0;
    }

    .hero .logo {
        max-width: 250px;
    }

    .cta-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

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

    .toc {
        padding: 1.5rem;
    }

    .whitepaper-content {
        font-size: 1rem;
    }

    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 44px;
        height: 44px;
        font-size: 1.25rem;
    }

}

@media (max-width: 480px) {
    h1 {
        font-size: 1.75rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero {
        padding: 1.5rem 0;
    }

    .value-props,
    .coming-soon {
        padding: 2rem 0;
    }
}


/* Print Styles */
@media print {
    .cta-buttons,
    .download-buttons,
    .back-to-top {
        display: none;
    }

    .hero,
    footer {
        border: none;
    }

    .whitepaper-content img {
        max-width: 100%;
        page-break-inside: avoid;
    }
}