/* Modern professional CSS for KC4YDX website */

/* CSS Custom Properties for consistent theming */
:root {
    --primary-color: #1a202c;
    --secondary-color: #2d3748;
    --accent-color: #3182ce;
    --accent-hover: #2b77cb;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    --background-light: #ffffff;
    --background-gray: #f7fafc;
    --background-darker: #edf2f7;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-attachment: fixed;
    min-height: 100vh;
    letter-spacing: -0.01em;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Modern Header */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 16px 0;
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.header h1 {
    text-align: center;
    color: var(--primary-color);
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.profile-images {
    text-align: center;
    margin: 16px 0;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.profile-images img {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    max-width: 100%;
    height: auto;
    transition: all 0.3s ease;
}

.profile-images img:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

/* Modern Navigation */
.nav-toggle {
    display: none;
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 12px 16px;
    cursor: pointer;
    border-radius: var(--radius-md);
    margin: 16px auto;
    font-size: 16px;
    font-weight: 600;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-sm);
}

.nav-toggle:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.navigation {
    background: var(--background-light);
    padding: 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}

.nav-menu {
    list-style: none;
}

.nav-menu li {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
}

.nav-menu li img {
    margin-right: 12px;
    vertical-align: middle;
    opacity: 0.7;
}

.nav-menu a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    padding: 12px 16px;
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
    flex: 1;
    font-size: 15px;
    letter-spacing: -0.01em;
}

.nav-menu a:hover {
    background: var(--background-gray);
    color: var(--accent-color);
    transform: translateX(4px);
}

.nav-menu a.current {
    background: var(--accent-color);
    color: white;
    font-weight: 600;
}

/* Modern Layout */
.layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 32px;
    align-items: start;
}

.sidebar {
    background: var(--background-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    position: sticky;
    top: 120px;
}

.content {
    background: var(--background-light);
    padding: 40px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    min-height: 600px;
    border: 1px solid var(--border-color);
}

/* Welcome Content */
.welcome-content {
    text-align: center;
    padding: 48px 24px;
}

.welcome-content h2 {
    color: var(--primary-color);
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.welcome-content p {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 32px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.welcome-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    margin-top: 24px;
}

/* Modern Footer */
.footer {
    background: var(--background-light);
    padding: 32px;
    text-align: center;
    margin-top: 48px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.external-links {
    margin: 24px 0;
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

.external-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    padding: 12px 20px;
    background: var(--background-gray);
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
    border: 1px solid var(--border-color);
}

.external-links a:hover {
    background: var(--accent-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.external-links p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

/* Page Headers */
.page-header {
    text-align: center;
    margin-bottom: 40px;
    padding-bottom: 24px;
    border-bottom: 2px solid var(--border-color);
}

.page-header h1 {
    color: var(--primary-color);
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 12px;
    letter-spacing: -0.02em;
}

.page-header h2 {
    color: var(--text-secondary);
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.page-header p {
    color: var(--text-tertiary);
    font-size: 1.1rem;
}

.page-nav {
    text-align: center;
    margin: 32px 0;
    padding: 20px;
    background: var(--background-gray);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.page-nav a {
    color: var(--accent-color);
    text-decoration: none;
    margin: 0 16px;
    font-weight: 600;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
}

.page-nav a:hover {
    background: var(--accent-color);
    color: white;
}

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

.content-section h2 {
    color: var(--primary-color);
    border-bottom: 3px solid var(--accent-color);
    padding-bottom: 12px;
    margin-bottom: 24px;
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.content-section h3 {
    color: var(--secondary-color);
    margin-top: 32px;
    margin-bottom: 16px;
    font-size: 1.35rem;
    font-weight: 600;
}

.content-section h4 {
    color: var(--text-primary);
    margin-top: 24px;
    margin-bottom: 12px;
    font-size: 1.1rem;
    font-weight: 600;
}

.content-section p {
    margin-bottom: 16px;
    color: var(--text-secondary);
    line-height: 1.7;
}

.content-section ul {
    margin-left: 24px;
    margin-bottom: 16px;
    color: var(--text-secondary);
}

/* Job/Experience Cards */
.job {
    background: var(--background-gray);
    padding: 24px;
    border-radius: var(--radius-md);
    margin-bottom: 24px;
    border-left: 4px solid var(--accent-color);
    transition: all 0.2s ease;
    border: 1px solid var(--border-color);
}

.job:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.job h3 {
    color: var(--primary-color);
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 1.2rem;
}

/* Skills and Training sections */
.skills, .training {
    background: var(--background-gray);
    padding: 24px;
    border-radius: var(--radius-md);
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}

.degree {
    background: var(--background-gray);
    padding: 20px;
    border-radius: var(--radius-md);
    margin-bottom: 20px;
    border-left: 4px solid var(--accent-color);
    border: 1px solid var(--border-color);
}

/* Modern Digital Counter */
.visitor-counter-display {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-family: 'Inter', sans-serif;
    margin: 16px 0;
    background: var(--background-gray);
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.counter-label {
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
}

.counter-digits {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: var(--radius-sm);
    padding: 6px 10px;
    display: inline-flex;
    gap: 2px;
    box-shadow: var(--shadow-sm);
}

.digit {
    background: var(--accent-color);
    color: white;
    font-family: 'Courier New', monospace;
    font-size: 16px;
    font-weight: bold;
    padding: 4px 6px;
    border-radius: 3px;
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
    min-width: 16px;
    text-align: center;
    box-shadow: inset 0 1px 2px rgba(255,255,255,0.2);
}

/* Patents Table Styling */
.patents-table {
    width: 100%;
    border-collapse: collapse;
    margin: 24px 0;
    background: var(--background-light);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.patents-table th,
.patents-table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.patents-table th {
    background: linear-gradient(135deg, var(--background-gray) 0%, var(--background-darker) 100%);
    font-weight: 600;
    color: var(--primary-color);
    font-size: 15px;
    letter-spacing: -0.01em;
}

.patents-table tr:nth-child(even) {
    background: var(--background-gray);
}

.patents-table tr:hover {
    background: #e6f3ff;
    transform: scale(1.01);
    transition: all 0.2s ease;
}

.patents-table a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
}

.patents-table a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

.patent-number {
    white-space: nowrap;
    font-weight: 600;
    color: var(--primary-color);
    font-family: 'Courier New', monospace;
    background: var(--background-gray);
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-size: 14px;
}

.filed-date {
    text-align: center;
    white-space: nowrap;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
    
    .layout {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .patents-table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
        border-radius: var(--radius-sm);
    }
    
    .patents-table th,
    .patents-table td {
        padding: 12px 10px;
        font-size: 14px;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .navigation {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--background-light);
        z-index: 1000;
        padding: 80px 24px 24px;
        overflow-y: auto;
    }
    
    .navigation.active {
        display: block;
    }
    
    .nav-close {
        position: absolute;
        top: 20px;
        right: 20px;
        background: var(--accent-color);
        color: white;
        border: none;
        padding: 12px 16px;
        cursor: pointer;
        border-radius: var(--radius-md);
        font-size: 16px;
        font-weight: 600;
    }
    
    .header h1 {
        font-size: 2rem;
    }
    
    .profile-images {
        flex-direction: column;
        align-items: center;
    }
    
    .profile-images img {
        max-width: 140px;
    }
    
    .content {
        padding: 24px;
    }
    
    .sidebar {
        position: static;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.75rem;
    }
    
    .profile-images img {
        max-width: 120px;
    }
    
    .nav-menu a {
        font-size: 14px;
        padding: 10px 14px;
    }
    
    .page-header h1 {
        font-size: 2.5rem;
    }
    
    .external-links {
        flex-direction: column;
    }
}