/* ===================================
   Responsive Design - Mobile First
   Base styles are for mobile, progressively enhanced
   =================================== */

/* ===================================
   Mobile Styles (< 640px) - Base
   =================================== */

/* Mobile Navigation */
@media screen and (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 400px;
        height: 100vh;
        background: var(--bg-primary);
        box-shadow: var(--shadow-xl);
        padding: var(--spacing-lg) var(--spacing-md);
        transition: right var(--transition-base);
        z-index: 1001;
    }

    .nav-menu.show-menu {
        right: 0;
    }

    .nav-list {
        flex-direction: column;
        gap: 0;
    }

    .nav-item {
        border-bottom: 1px solid var(--border-light);
    }

    .nav-link {
        display: block;
        padding: var(--spacing-sm);
    }

    .nav-toggle {
        display: flex;
    }

    .nav-close {
        display: block;
    }

    /* Hero Section Mobile */
    .hero {
        padding-top: calc(var(--header-height) + var(--spacing-md));
        padding-bottom: var(--spacing-md);
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

    .hero-content {
        order: 2;
        text-align: center;
    }

    .hero-image {
        order: 1;
    }

    .hero-image-wrapper {
        max-width: 250px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .button {
        width: 100%;
        max-width: 300px;
    }

    /* Section Spacing Mobile */
    .section {
        padding: var(--spacing-md) 0;
    }

    /* Stats Grid Mobile */
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
    }

    /* Education Grid Mobile */
    .education-grid {
        grid-template-columns: 1fr;
    }

    /* Timeline Mobile */
    .timeline {
        padding-left: var(--spacing-sm);
    }

    .timeline-marker {
        left: -26px;
        width: 10px;
        height: 10px;
    }

    .timeline-content {
        padding: var(--spacing-sm);
    }

    .timeline-header {
        flex-direction: column;
        align-items: flex-start;
    }

    /* Skills Grid Mobile */
    .skills-grid {
        grid-template-columns: 1fr;
    }

    /* Publications Grid Mobile */
    .publications-grid {
        grid-template-columns: 1fr;
    }

    /* Contact Content Mobile */
    .contact-content {
        grid-template-columns: 1fr;
    }

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

    /* Footer Mobile */
    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-sm);
    }

    .footer-links {
        justify-content: center;
    }

    /* Back to Top Button Mobile */
    .back-to-top {
        bottom: 1rem;
        right: 1rem;
        width: 45px;
        height: 45px;
    }
}

/* ===================================
   Small Mobile (< 480px)
   =================================== */
@media screen and (max-width: 480px) {
    /* Adjust font sizes for very small screens */
    :root {
        --fs-5xl: 2rem;
        --fs-4xl: 1.75rem;
        --fs-3xl: 1.5rem;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    .nav-logo {
        font-size: var(--fs-base);
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: var(--fs-base);
    }

    .hero-description {
        font-size: var(--fs-base);
    }

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

    .stat-number {
        font-size: var(--fs-3xl);
    }

    .button {
        padding: 0.75rem 1.5rem;
        font-size: var(--fs-sm);
    }

    .section-title {
        font-size: 1.5rem;
    }

    .subsection-title {
        font-size: 1.25rem;
    }
}

/* ===================================
   Tablet Styles (640px - 1024px)
   =================================== */
@media screen and (min-width: 640px) and (max-width: 1024px) {
    /* Hero Section Tablet */
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }

    .hero-content {
        order: 2;
        text-align: center;
    }

    .hero-image {
        order: 1;
    }

    .hero-image-wrapper {
        max-width: 300px;
    }

    .hero-buttons {
        justify-content: center;
    }

    /* Stats Grid Tablet */
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Skills Grid Tablet */
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Publications Grid Tablet */
    .publications-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Social Grid Tablet */
    .social-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ===================================
   Desktop Styles (> 1024px)
   =================================== */
@media screen and (min-width: 1024px) {
    /* Container Wider */
    .container {
        padding: 0 var(--spacing-md);
    }

    /* Hero Grid Enhanced */
    .hero-container {
        gap: var(--spacing-xl);
    }

    /* Stats Grid Desktop */
    .stats-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    /* Skills Grid Desktop */
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    /* Publications Grid Desktop */
    .publications-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    /* Timeline Enhanced */
    .timeline {
        padding-left: var(--spacing-lg);
    }

    .timeline-marker {
        left: -42px;
        width: 14px;
        height: 14px;
    }
}

/* ===================================
   Large Desktop (> 1440px)
   =================================== */
@media screen and (min-width: 1440px) {
    :root {
        --max-width: 1400px;
    }

    .section {
        padding: var(--spacing-xl) 0;
    }

    .hero {
        padding-top: calc(var(--header-height) + var(--spacing-xl) + var(--spacing-md));
    }

    .hero-image-wrapper {
        max-width: 450px;
    }
}

/* ===================================
   Print Styles
   =================================== */
@media print {
    .header,
    .nav,
    .hero-buttons,
    .back-to-top,
    .footer {
        display: none;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
        color: #000;
        background: #fff;
    }

    .section {
        page-break-inside: avoid;
        padding: 1rem 0;
    }

    .hero {
        background: none;
        padding-top: 0;
    }

    .publication-card,
    .timeline-item,
    .skill-card {
        page-break-inside: avoid;
    }

    a {
        text-decoration: underline;
    }

    a[href]::after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
    }
}

/* ===================================
   Landscape Mobile Specific
   =================================== */
@media screen and (max-width: 768px) and (orientation: landscape) {
    .hero {
        padding-top: calc(var(--header-height) + var(--spacing-sm));
        padding-bottom: var(--spacing-sm);
    }

    .hero-container {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-md);
    }

    .hero-content {
        order: 1;
        text-align: left;
    }

    .hero-image {
        order: 2;
    }

    .hero-image-wrapper {
        max-width: 200px;
    }

    .hero-buttons {
        justify-content: flex-start;
    }

    .button {
        width: auto;
    }
}

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

/* ===================================
   Dark Mode Support (Future Enhancement)
   =================================== */
@media (prefers-color-scheme: dark) {
    /* Uncomment to enable automatic dark mode based on system preference
    :root {
        --text-primary: #ecf0f1;
        --text-secondary: #bdc3c7;
        --bg-primary: #1a1a1a;
        --bg-secondary: #2c2c2c;
        --bg-tertiary: #3a3a3a;
        --border-color: #4a4a4a;
    }
    */
}

/* ===================================
   High Contrast Mode
   =================================== */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #1e4464;
        --text-primary: #000000;
        --border-color: #000000;
    }

    .button {
        border-width: 3px;
    }

    .nav-link {
        font-weight: 600;
    }
}

/* ===================================
   Hover Support Detection
   =================================== */
@media (hover: none) {
    /* Remove hover effects for touch devices */
    .button-primary:hover,
    .button-secondary:hover,
    .stat-card:hover,
    .skill-card:hover,
    .publication-card:hover,
    .contact-item:hover,
    .timeline-content:hover {
        transform: none;
        box-shadow: var(--shadow-sm);
    }

    .social-link:hover {
        transform: none;
    }

    .back-to-top:hover {
        transform: none;
    }
}

/* ===================================
   Touch Device Optimizations
   =================================== */
@media (pointer: coarse) {
    /* Increase touch targets for better accessibility */
    .nav-link,
    .button,
    .social-link,
    .contact-value {
        min-height: 44px;
        display: inline-flex;
        align-items: center;
    }

    .back-to-top {
        width: 55px;
        height: 55px;
    }
}