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

:root {
    --primary-color: #4CAF50;
    --primary-dark: #388e3c;
    --text-primary: #1a1a1a;
    --text-secondary: #595959;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --link-color: #1976d2;
    --link-hover: #1565c0;
    --callout-info-bg: #e3f2fd;
    --callout-info-border: #2196f3;
    --callout-warning-bg: #fff3e0;
    --callout-warning-border: #ff9800;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Top Navigation */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.nav-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 16px 24px;
}

.back-button {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s ease;
}

    .back-button:hover {
        color: var(--primary-color);
    }

    .back-button svg {
        width: 20px;
        height: 20px;
    }

/* Container Layout */
.container {
    max-width: 1400px;
    margin: 80px auto 0;
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 40px;
    padding: 0 24px 80px;
}

/* Sidebar */
.sidebar {
    position: relative;
}

.sidebar-sticky {
    position: sticky;
    top: 100px;
    background: var(--bg-white);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    max-height: calc(100vh - 120px);
    overflow-y: auto;
}

.sidebar h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
}

.toc {
    display: flex;
    flex-direction: column;
}

    .toc a {
        color: var(--text-secondary);
        text-decoration: none;
        font-size: 14px;
        padding: 8px 12px;
        border-radius: 6px;
        transition: all 0.2s ease;
        margin-bottom: 2px;
    }

        .toc a:hover {
            background: var(--bg-light);
            color: var(--primary-color);
        }

/* Main Content */
.content {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 48px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    min-height: 100vh;
}

/* Header */
.header {
    margin-bottom: 48px;
    padding-bottom: 24px;
    border-bottom: 3px solid var(--primary-color);
}

    .header h1 {
        font-size: 36px;
        font-weight: 700;
        color: var(--text-primary);
        margin-bottom: 8px;
    }

.last-updated {
    color: var(--text-secondary);
    font-size: 14px;
}

    .last-updated strong {
        color: var(--text-primary);
    }

/* Sections */
.section {
    margin-bottom: 48px;
}

    .section:last-child {
        margin-bottom: 0;
    }

h2 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding-top: 24px;
    scroll-margin-top: 100px;
}

h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-top: 24px;
    margin-bottom: 16px;
}

p {
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.7;
    margin-bottom: 16px;
}

/* Lists */
ul, ol {
    margin-left: 24px;
    margin-bottom: 20px;
    color: var(--text-secondary);
}

    ul li, ol li {
        margin-bottom: 12px;
        padding-left: 8px;
        line-height: 1.7;
    }

    ul.payment-methods {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 12px;
        list-style: none;
        margin-left: 0;
    }

        ul.payment-methods li {
            background: var(--bg-light);
            padding: 12px 16px;
            border-radius: 8px;
            text-align: center;
            font-weight: 500;
        }

    ul.prohibited-list li {
        background: var(--bg-light);
        padding: 12px 16px;
        border-radius: 8px;
        margin-bottom: 8px;
        border-left: 3px solid var(--callout-warning-border);
    }

/* Links */
a.link {
    color: var(--link-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

    a.link:hover {
        color: var(--link-hover);
        text-decoration: underline;
    }

/* Callouts */
.callout {
    padding: 20px 24px;
    border-radius: 8px;
    margin: 24px 0;
    border-left: 4px solid;
}

    .callout p {
        margin-bottom: 0;
    }

        .callout p:not(:last-child) {
            margin-bottom: 12px;
        }

.callout-info {
    background: var(--callout-info-bg);
    border-left-color: var(--callout-info-border);
}

    .callout-info strong {
        color: var(--callout-info-border);
    }

.callout-warning {
    background: var(--callout-warning-bg);
    border-left-color: var(--callout-warning-border);
}

    .callout-warning strong {
        color: var(--callout-warning-border);
    }

/* Contact Info */
.contact-info {
    background: var(--bg-light);
    padding: 24px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

    .contact-info p {
        margin-bottom: 8px;
    }

        .contact-info p:last-child {
            margin-bottom: 0;
        }

/* Scrollbar Styling */
.sidebar-sticky::-webkit-scrollbar {
    width: 6px;
}

.sidebar-sticky::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar-sticky::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

    .sidebar-sticky::-webkit-scrollbar-thumb:hover {
        background: #999;
    }

/* Tablet Styles */
@media (max-width: 1024px) {
    .container {
        grid-template-columns: 240px 1fr;
        gap: 24px;
        padding: 0 16px 60px;
    }

    .sidebar-sticky {
        padding: 20px;
    }

    .content {
        padding: 32px 24px;
    }

    .header h1 {
        font-size: 32px;
    }

    h2 {
        font-size: 24px;
    }

    h3 {
        font-size: 18px;
    }
}

/* Mobile Styles */
@media (max-width: 768px) {
    .container {
        grid-template-columns: 1fr;
        margin-top: 70px;
        padding: 0 12px 40px;
    }

    .sidebar {
        display: none;
    }

    .content {
        padding: 24px 20px;
    }

    .header {
        margin-bottom: 32px;
    }

        .header h1 {
            font-size: 28px;
        }

    h2 {
        font-size: 22px;
        padding-top: 16px;
    }

    h3 {
        font-size: 18px;
        margin-top: 20px;
    }

    p {
        font-size: 15px;
    }

    .section {
        margin-bottom: 36px;
    }

    .callout {
        padding: 16px 20px;
        margin: 20px 0;
    }

    ul, ol {
        margin-left: 20px;
    }

        ul.payment-methods {
            grid-template-columns: 1fr;
        }
}

/* Small Mobile */
@media (max-width: 480px) {
    .nav-content {
        padding: 12px 16px;
    }

    .back-button {
        font-size: 13px;
    }

    .content {
        padding: 20px 16px;
        border-radius: 8px;
    }

    .header h1 {
        font-size: 24px;
    }

    h2 {
        font-size: 20px;
    }

    h3 {
        font-size: 17px;
    }

    p, ul li, ol li {
        font-size: 14px;
    }

    .contact-info {
        padding: 20px;
    }
}

/* Print Styles */
@media print {
    body {
        background: white;
    }

    .top-nav,
    .sidebar,
    .back-button {
        display: none;
    }

    .container {
        display: block;
        margin: 0;
        padding: 0;
    }

    .content {
        box-shadow: none;
        padding: 0;
    }

    .section {
        page-break-inside: avoid;
    }

    h2 {
        page-break-after: avoid;
    }
}

/* Focus Styles for Accessibility */
a:focus-visible,
.toc a:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Selection Color */
::selection {
    background: var(--primary-color);
    color: white;
}

::-moz-selection {
    background: var(--primary-color);
    color: white;
}