/* ============================================
   Manil Shrestha Portfolio - CSS Stylesheet
   Clean + Dark Mode Design
   ============================================ */

/* CSS Variables for Theme Support */
:root {
    /* Light Theme (Default) */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f1f3f4;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a68;
    --text-muted: #6c6c8a;
    --accent-primary: #2563eb;
    --accent-secondary: #3b82f6;
    --accent-hover: #1d4ed8;
    --border-color: #e5e7eb;
    --card-bg: #ffffff;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
    --card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.1);
    --nav-bg: rgba(255, 255, 255, 0.95);
    --code-bg: #f1f3f4;
    --success: #10b981;
    --warning: #f59e0b;
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #252542;
    --text-primary: #f1f1f4;
    --text-secondary: #b4b4c8;
    --text-muted: #8888a4;
    --accent-primary: #3b82f6;
    --accent-secondary: #60a5fa;
    --accent-hover: #2563eb;
    --border-color: #2d2d4a;
    --card-bg: #1a1a2e;
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
    --card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.4);
    --nav-bg: rgba(15, 15, 26, 0.95);
    --code-bg: #252542;
}

/* Reset & Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.25rem; }

p {
    color: var(--text-secondary);
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--accent-hover);
}

strong {
    color: var(--text-primary);
    font-weight: 600;
}

em {
    font-style: italic;
}

/* ============================================
   Navigation
   ============================================ */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Theme Toggle */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    color: var(--text-secondary);
    transition: background-color 0.2s ease, color 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.sun-icon { display: none; }
.moon-icon { display: block; }

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: all 0.3s ease;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 64px;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 80px 24px;
    text-align: center;
}

.hero-greeting {
    font-size: 1.125rem;
    color: var(--accent-primary);
    font-weight: 500;
    margin-bottom: 8px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.hero-tagline {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.hero-quote {
    font-size: 1rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 32px;
    padding: 16px 24px;
    background: var(--bg-secondary);
    border-radius: 8px;
    border-left: 3px solid var(--accent-primary);
}

.hero-buttons {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-primary {
    background: var(--accent-primary);
    color: #ffffff;
}

.btn-primary:hover {
    background: var(--accent-hover);
    color: #ffffff;
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

/* ============================================
   Intro Section
   ============================================ */
.intro {
    padding: 80px 0;
    background: var(--bg-secondary);
}

.intro-text {
    font-size: 1.25rem;
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto 24px;
    text-align: center;
}

.intro-text:last-child {
    margin-bottom: 0;
}

/* ============================================
   Highlights / Features Grid
   ============================================ */
.highlights {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 48px;
    font-size: 2rem;
}

.highlights-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.highlight-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
    transition: all 0.3s ease;
}

.highlight-card:hover {
    box-shadow: var(--card-shadow-hover);
    transform: translateY(-4px);
}

.highlight-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: var(--accent-primary);
}

.highlight-card h3 {
    margin-bottom: 8px;
}

.highlight-card p {
    font-size: 0.9375rem;
}

/* ============================================
   Recent Work / Publications Preview
   ============================================ */
.recent-work {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.publications-preview {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 32px;
}

.pub-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 24px;
    display: flex;
    align-items: flex-start;
    gap: 20px;
    transition: all 0.2s ease;
}

.pub-card:hover {
    border-color: var(--accent-primary);
}

.pub-year {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.875rem;
    color: var(--accent-primary);
    font-weight: 500;
    flex-shrink: 0;
}

.pub-card h3 {
    font-size: 1rem;
    margin-bottom: 4px;
}

.pub-venue {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.view-all-link {
    display: inline-flex;
    align-items: center;
    font-weight: 500;
}

/* ============================================
   Page Headers
   ============================================ */
.page-header {
    padding: 140px 0 60px;
    background: var(--bg-secondary);
    text-align: center;
}

.page-header h1 {
    margin-bottom: 16px;
}

.page-subtitle {
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

.scholar-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-top: 24px;
    padding: 10px 20px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.scholar-link:hover {
    border-color: var(--accent-primary);
    background: var(--bg-tertiary);
}

/* ============================================
   About Page
   ============================================ */
.about-content {
    padding: 80px 0;
}

.about-intro {
    max-width: 800px;
    margin-bottom: 64px;
}

.about-intro .lead {
    font-size: 1.375rem;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.about-intro p {
    font-size: 1.0625rem;
    margin-bottom: 16px;
}

.about-section {
    margin-bottom: 64px;
}

.about-section h2 {
    margin-bottom: 32px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 32px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    padding-bottom: 32px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: -32px;
    top: 4px;
    width: 16px;
    height: 16px;
    background: var(--accent-primary);
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
}

.timeline-content h3 {
    color: var(--accent-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9375rem;
    margin-bottom: 4px;
}

.timeline-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.skill-category {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
}

.skill-category h3 {
    font-size: 1rem;
    margin-bottom: 16px;
    color: var(--accent-primary);
}

.skill-list {
    list-style: none;
}

.skill-list li {
    padding: 6px 0;
    font-size: 0.9375rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.skill-list li:last-child {
    border-bottom: none;
}

/* Focus Cards */
.focus-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.focus-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
    transition: all 0.3s ease;
}

.focus-card:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--card-shadow-hover);
}

.focus-card h3 {
    margin-bottom: 12px;
}

/* ============================================
   Projects Page
   ============================================ */
.projects-content {
    padding: 80px 0;
}

.projects-grid {
    display: grid;
    gap: 32px;
}

.project-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 32px;
    transition: all 0.3s ease;
}

.project-card:hover {
    box-shadow: var(--card-shadow-hover);
}

.project-card {
    border-left: 4px solid var(--accent-primary);
}

.project-card.upcoming {
    border-left: 4px solid var(--warning);
    opacity: 0.9;
}

.project-header {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.project-tag {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 4px 10px;
    background: var(--bg-secondary);
    color: var(--text-muted);
    border-radius: 4px;
}

.project-card h2 {
    font-size: 1.375rem;
    margin-bottom: 8px;
}

.project-tldr {
    font-size: 1.0625rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.project-details {
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.project-details h3 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin: 16px 0 8px;
}

.project-details h3:first-child {
    margin-top: 0;
}

.project-details ul {
    list-style: none;
    padding-left: 0;
}

.project-details li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 6px;
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.project-details li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
}

.tech-stack {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8125rem;
    color: var(--text-muted);
    background: var(--bg-secondary);
    padding: 8px 12px;
    border-radius: 6px;
}

.project-links {
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.project-link {
    font-weight: 500;
    font-size: 0.9375rem;
}

/* ============================================
   Publications Page
   ============================================ */
.publications-content {
    padding: 80px 0;
}

.pub-year-section {
    margin-bottom: 48px;
}

.pub-year-header {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    color: var(--accent-primary);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
}

.publication-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 28px;
    margin-bottom: 16px;
    transition: all 0.2s ease;
}

.publication-link {
    display: block;
    text-decoration: none;
    color: inherit;
    margin-bottom: 16px;
}

.publication-link:hover .publication-card {
    border-color: var(--accent-primary);
    box-shadow: var(--card-shadow-hover);
    transform: translateY(-2px);
}

.publication-link .publication-card {
    margin-bottom: 0;
}

.publication-card {
    border-left: 4px solid var(--accent-primary);
    cursor: pointer;
}

.pub-meta {
    display: flex;
    gap: 12px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.pub-type {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 4px 10px;
    background: var(--bg-secondary);
    color: var(--text-muted);
    border-radius: 4px;
}

.pub-citations {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    background: var(--success);
    color: #ffffff;
    border-radius: 4px;
}

.publication-card h3 {
    font-size: 1.125rem;
    margin-bottom: 8px;
    line-height: 1.4;
}

.pub-authors {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.publication-card .pub-venue {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-style: italic;
    margin-bottom: 12px;
}

.pub-abstract {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.pub-links {
    margin-top: 16px;
    display: flex;
    gap: 12px;
}

.pub-link {
    font-size: 0.875rem;
    font-weight: 500;
    padding: 6px 12px;
    background: var(--bg-secondary);
    border-radius: 6px;
    transition: all 0.2s ease;
}

.pub-link:hover {
    background: var(--accent-primary);
    color: #ffffff;
}

/* ============================================
   Contact Page
   ============================================ */
.contact-content {
    padding: 80px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
}

.contact-info h2,
.contact-form-section h2 {
    margin-bottom: 24px;
}

.contact-info > p {
    font-size: 1.0625rem;
    margin-bottom: 32px;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: all 0.2s ease;
}

.contact-method:hover {
    border-color: var(--accent-primary);
    background: var(--bg-secondary);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent-primary);
    flex-shrink: 0;
}

.contact-details h3 {
    font-size: 0.9375rem;
    margin-bottom: 2px;
}

.contact-details p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Contact Form */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 12px 16px;
    font-size: 1rem;
    font-family: inherit;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    transition: border-color 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-note {
    font-size: 0.8125rem;
    color: var(--text-muted);
    margin-top: 16px;
}

/* ============================================
   Footer
   ============================================ */
.footer {
    padding: 48px 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-content p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 24px;
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

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

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--nav-bg);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border-color);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 280px;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }

    .pub-card {
        flex-direction: column;
        gap: 8px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-content {
        padding: 60px 16px;
    }

    .hero-title {
        font-size: 2rem;
    }

    .highlight-card,
    .project-card,
    .publication-card {
        padding: 24px;
    }
}