/* ============================================
   RESPONSIVE HEADER - COMPLETE CSS
   Custom Font, Flexbox Layout, Mobile Menu
   ============================================ */

/* ============================================
   CUSTOM FONT LOADING
   ============================================ */
@font-face {
    font-family: 'CustomBrand';
    src: url('../fonts/VHASS-Font.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
    font-display: swap; /* Prevents invisible text during load */
}

/* ============================================
   CSS CUSTOM PROPERTIES
   ============================================ */
:root {
    /* Colors */
    --color-primary: #2563eb;
    --color-primary-dark: #1e40af;
    --color-text: #1f2937;
    --color-white: #ffffff;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-800: #1f2937;
    
    /* Spacing */
    --header-height: 70px;
    --container-padding: 1.5rem;
    
    /* Transitions */
    --transition-speed: 300ms;
    --transition-timing: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: var(--color-text);
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   HEADER STYLES
   ============================================ */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: var(--color-white);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    height: var(--header-height);
}

.header-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--container-padding);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

/* ============================================
   BRAND / LOGO SECTION
   ============================================ */
.brand {
    display: flex;
    align-items: center;
    z-index: 1001; /* Above mobile menu */
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: opacity var(--transition-speed) var(--transition-timing);
}

.brand-link:hover {
    opacity: 0.8;
}

.brand-link:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 4px;
    border-radius: 4px;
}

.logo {
    width: 40px;
    height: 40px;
    /* Placeholder background for demo */
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    border-radius: 4px;
}

.brand-text {
    font-family: 'CustomBrand', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

/* ============================================
   NAVIGATION - DESKTOP
   ============================================ */
.main-nav {
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link {
    display: block;
    padding: 0.625rem 1rem;
    color: var(--color-text);
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: 6px;
    transition: all var(--transition-speed) var(--transition-timing);
    position: relative;
}

/* Hover State */
.nav-link:hover {
    color: var(--color-primary);
    background-color: var(--color-gray-100);
}

/* Active State */
.nav-link.active {
    color: var(--color-primary);
    background-color: rgba(37, 99, 235, 0.1);
}

/* Focus State for Accessibility */
.nav-link:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Optional: Underline animation on hover */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0.25rem;
    left: 1rem;
    right: 1rem;
    height: 2px;
    background-color: var(--color-primary);
    transform: scaleX(0);
    transition: transform var(--transition-speed) var(--transition-timing);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: scaleX(1);
}

/* ============================================
   MOBILE MENU TOGGLE BUTTON
   ============================================ */
.menu-toggle {
    display: none; /* Hidden on desktop */
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 1001; /* Above mobile menu */
    width: 44px; /* Minimum touch target size */
    height: 44px;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: background-color var(--transition-speed) var(--transition-timing);
}

.menu-toggle:hover {
    background-color: var(--color-gray-100);
}

.menu-toggle:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.hamburger {
    display: flex;
    flex-direction: column;
    gap: 5px;
    width: 24px;
}

.hamburger-line {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--color-text);
    border-radius: 2px;
    transition: all var(--transition-speed) var(--transition-timing);
}

/* Hamburger Animation - Active State */
.menu-toggle.active .hamburger-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active .hamburger-line:nth-child(2) {
    opacity: 0;
    transform: translateX(-10px);
}

.menu-toggle.active .hamburger-line:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ============================================
   RESPONSIVE - MOBILE STYLES
   ============================================ */
@media (max-width: 768px) {
    
    /* Show mobile menu toggle */
    .menu-toggle {
        display: flex;
    }
    
    /* Mobile Navigation */
    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background-color: var(--color-white);
        padding: 2rem var(--container-padding);
        
        /* Hidden by default */
        transform: translateX(100%);
        opacity: 0;
        visibility: hidden;
        
        /* Smooth transition */
        transition: transform var(--transition-speed) var(--transition-timing),
                    opacity var(--transition-speed) var(--transition-timing),
                    visibility var(--transition-speed) var(--transition-timing);
        
        /* Add subtle shadow */
        box-shadow: -2px 0 8px rgba(0, 0, 0, 0.1);
    }
    
    /* Mobile Navigation - Active State */
    .main-nav.active {
        transform: translateX(0);
        opacity: 1;
        visibility: visible;
    }
    
    /* Mobile Nav List */
    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
    }
    
    /* Mobile Nav Links */
    .nav-link {
        padding: 1rem 1.25rem;
        font-size: 1.125rem;
        border-left: 3px solid transparent;
        border-radius: 0;
    }
    
    .nav-link:hover,
    .nav-link.active {
        border-left-color: var(--color-primary);
        background-color: var(--color-gray-100);
    }
    
    .nav-link::after {
        display: none; /* Remove underline on mobile */
    }
    
    /* Prevent body scroll when menu is open */
    body.menu-open {
        overflow: hidden;
    }
}

/* ============================================
   TABLET STYLES
   ============================================ */
@media (min-width: 769px) and (max-width: 1024px) {
    .nav-list {
        gap: 0.25rem;
    }
    
    .nav-link {
        padding: 0.5rem 0.75rem;
        font-size: 0.875rem;
    }
}

/* ============================================
   DEMO CONTENT STYLES (FOR DEMONSTRATION)
   ============================================ */
.demo-content {
    margin-top: var(--header-height);
    padding: 3rem var(--container-padding);
    min-height: 100vh;
}

.demo-container {
    max-width: 800px;
    margin: 0 auto;
}

.demo-content h1 {
    color: var(--color-text);
    margin-bottom: 1rem;
    font-size: 2.5rem;
}

.demo-content p {
    margin-bottom: 1rem;
    color: var(--color-gray-800);
    font-size: 1.125rem;
}

.demo-box {
    background-color: var(--color-gray-100);
    padding: 2rem;
    border-radius: 12px;
    margin: 2rem 0;
}

.demo-box h2 {
    margin-bottom: 1rem;
    color: var(--color-text);
}

.demo-box ul {
    list-style: none;
    padding: 0;
}

.demo-box li {
    padding: 0.5rem 0;
    font-size: 1rem;
    color: var(--color-gray-800);
}

/* ============================================
   ACCESSIBILITY IMPROVEMENTS
   ============================================ */

/* Skip to main content link (optional) */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* Reduced motion for accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .site-header {
        border-bottom: 2px solid var(--color-text);
    }
    
    .nav-link:hover,
    .nav-link.active {
        outline: 2px solid currentColor;
    }
}