/* 5G Infrastructure Informational Website - Main Stylesheet */

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

:root {
    --color-bg: #F8F8F6;
    --color-bg-white: #FFFFFF;
    --color-text-primary: #2C2C2C;
    --color-text-secondary: #4A4A4A;
    --color-text-muted: #6B6B6B;
    --color-accent-red: #B85C38;
    --color-accent-red-light: #D47454;
    --color-separator: #B0B0B0;
    --color-border: #D0D0D0;
    --color-link: #1a5490;
    --color-link-hover: #2a64a8;
    
    --font-primary: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-size-base: 16px;
    --line-height-body: 1.7;
    --line-height-heading: 1.3;
    
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-xxl: 4rem;
    
    --max-width-content: 900px;
    --max-width-wide: 1200px;
}

body {
    font-family: var(--font-primary);
    font-size: var(--font-size-base);
    line-height: var(--line-height-body);
    color: var(--color-text-primary);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: var(--line-height-heading);
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
}

h2 {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-separator);
}

h3 {
    font-size: 1.4rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

h4 {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

p {
    margin-bottom: var(--spacing-md);
    max-width: 75ch;
}

a {
    color: var(--color-link);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--color-link-hover);
    text-decoration-thickness: 2px;
}

/* Layout Structure */
.container {
    max-width: var(--max-width-content);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

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

/* Header & Navigation */
header {
    background-color: var(--color-bg-white);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    margin-bottom: var(--spacing-xl);
}

.site-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.site-subtitle {
    font-size: 1rem;
    color: var(--color-text-muted);
    font-weight: 400;
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

nav a {
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: var(--spacing-xs) 0;
    border-bottom: 2px solid transparent;
    transition: all 0.2s ease;
}

nav a:hover,
nav a.active {
    color: var(--color-accent-red);
    border-bottom-color: var(--color-accent-red);
}

/* Main Content */
main {
    min-height: 60vh;
}

.page-header {
    margin-bottom: var(--spacing-xl);
}

.page-header h1 {
    margin-bottom: var(--spacing-md);
}

.disclaimer-block {
    background-color: var(--color-bg-white);
    border-left: 4px solid var(--color-accent-red);
    padding: var(--spacing-md);
    margin: var(--spacing-lg) 0;
    font-size: 0.95rem;
    color: var(--color-text-secondary);
}

.disclaimer-block p {
    margin-bottom: 0;
}

/* Content Sections */
section {
    margin-bottom: var(--spacing-xxl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid var(--color-border);
}

section:last-child {
    border-bottom: none;
}

/* Lists */
ul, ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

li {
    margin-bottom: var(--spacing-sm);
}

/* Glossary Items */
.glossary-item {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background-color: var(--color-bg-white);
    border: 1px solid var(--color-border);
}

.glossary-term {
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
}

.glossary-definition {
    color: var(--color-text-secondary);
    margin-bottom: 0;
}

/* Q&A Blocks */
.qa-block {
    margin-bottom: var(--spacing-lg);
}

.qa-question {
    font-weight: 600;
    color: var(--color-accent-red);
    margin-bottom: var(--spacing-sm);
    font-size: 1.1rem;
}

.qa-answer {
    color: var(--color-text-secondary);
    margin-bottom: 0;
    padding-left: var(--spacing-md);
}

/* Technical Diagrams */
.diagram-container {
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-lg);
    background-color: var(--color-bg-white);
    border: 1px solid var(--color-border);
    text-align: center;
}

.diagram-container svg {
    max-width: 100%;
    height: auto;
}

.diagram-caption {
    margin-top: var(--spacing-md);
    font-size: 0.9rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* Contact Form */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-sm);
    font-size: 1rem;
    font-family: var(--font-primary);
    border: 1px solid var(--color-border);
    background-color: var(--color-bg-white);
    color: var(--color-text-primary);
    border-radius: 4px;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--color-accent-red);
    box-shadow: 0 0 0 3px rgba(184, 92, 56, 0.1);
}

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

button[type="submit"] {
    background-color: var(--color-accent-red);
    color: white;
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

button[type="submit"]:hover {
    background-color: var(--color-accent-red-light);
}

/* Footer */
footer {
    background-color: var(--color-bg-white);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-xxl);
}

.footer-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.footer-disclaimer {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    padding: var(--spacing-md);
    background-color: var(--color-bg);
    border-left: 3px solid var(--color-accent-red);
}

.footer-disclaimer p {
    margin-bottom: var(--spacing-sm);
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    font-size: 0.9rem;
}

.footer-links a {
    color: var(--color-text-secondary);
    text-decoration: none;
}

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

.copyright {
    margin-top: var(--spacing-lg);
    font-size: 0.85rem;
    color: var(--color-text-muted);
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --font-size-base: 15px;
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
        --spacing-xxl: 3rem;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    nav ul {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .container,
    .container-wide {
        padding: 0 var(--spacing-md);
    }
}

@media (max-width: 480px) {
    :root {
        --font-size-base: 14px;
    }
    
    h1 {
        font-size: 1.75rem;
    }
    
    .container,
    .container-wide {
        padding: 0 var(--spacing-sm);
    }
}

/* Print Styles */
@media print {
    body {
        background-color: white;
        color: black;
    }
    
    header,
    footer,
    nav {
        display: none;
    }
    
    section {
        page-break-inside: avoid;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
}