/* ============================================
   Aashish Poudel — Personal Website Theme
   Clean, simple design. No gradients.
   ============================================ */

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

:root {
    --color-bg: #ffffff;
    --color-surface: #f8f9fa;
    --color-border: #e2e5e9;
    --color-text: #1a1a2e;
    --color-text-secondary: #555b6e;
    --color-accent: #2563eb;
    --color-accent-hover: #1d4ed8;
    --color-code-bg: #f1f3f5;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --container-width: 780px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --radius: 6px;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

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

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

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

/* --- Header --- */
.site-header {
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 0;
    background: var(--color-bg);
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.site-logo:hover {
    color: var(--color-accent);
}

.site-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-xs);
}

.site-nav ul li a {
    display: block;
    padding: var(--spacing-xs) var(--spacing-sm);
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius);
    transition: color 0.2s ease, background-color 0.2s ease;
}

.site-nav ul li a:hover,
.site-nav ul li a.active {
    color: var(--color-accent);
    background-color: var(--color-surface);
}

/* Mobile toggle */
.mobile-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
    flex-direction: column;
    gap: 5px;
}

.mobile-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: transform 0.2s ease;
}

/* --- Main Content --- */
.site-main {
    flex: 1;
    padding: var(--spacing-3xl) 0;
}

/* --- Typography in content --- */
.site-main h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
}

.site-main h2 {
    font-size: 1.35rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-top: var(--spacing-2xl);
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--color-border);
}

.site-main h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.site-main p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.site-main ul, .site-main ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-xl);
}

.site-main li {
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-secondary);
}

.site-main code {
    font-family: var(--font-mono);
    font-size: 0.85em;
    background: var(--color-code-bg);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--color-text);
}

.site-main pre {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--spacing-md);
    overflow-x: auto;
    margin-bottom: var(--spacing-lg);
}

.site-main pre code {
    background: none;
    padding: 0;
    font-size: 0.85rem;
    line-height: 1.6;
}

/* --- Hero Section (Home) --- */
.hero-section {
    margin-bottom: var(--spacing-3xl);
}

.hero-section h1 {
    font-size: 2.4rem;
    margin-bottom: var(--spacing-sm);
}

.highlight {
    color: var(--color-accent);
}

.subtitle {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
}

.intro-text {
    font-size: 1.05rem;
    line-height: 1.8;
    max-width: 600px;
}

.quick-links {
    margin-top: var(--spacing-xl);
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 10px 22px;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius);
    transition: all 0.2s ease;
    background: var(--color-accent);
    color: #fff;
    border: 2px solid var(--color-accent);
}

.btn:hover {
    background: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
    color: #fff;
}

.btn-outline {
    background: transparent;
    color: var(--color-accent);
}

.btn-outline:hover {
    background: var(--color-accent);
    color: #fff;
}

/* --- About & Research Interests --- */
.about-section,
.research-interests {
    margin-bottom: var(--spacing-2xl);
}

.research-interests ul {
    list-style: none;
    padding-left: 0;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.research-interests li {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-secondary);
}

/* --- TIL Page --- */
.til-page .page-description {
    font-size: 1.05rem;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-text-secondary);
}

.til-entry {
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--color-border);
}

.til-entry:last-child {
    border-bottom: none;
}

.til-date {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

.til-entry h3 {
    margin-bottom: var(--spacing-sm);
}

.til-entry p {
    margin-bottom: var(--spacing-sm);
}

/* --- Publications Page --- */
.publications-page h1 {
    margin-bottom: var(--spacing-2xl);
}

.pub-section {
    margin-bottom: var(--spacing-2xl);
}

.pub-section h2 {
    font-size: 1.15rem;
    margin-top: 0;
    margin-bottom: var(--spacing-md);
}

.pub-entry {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
}

.pub-entry:last-child {
    border-bottom: none;
}

.pub-authors {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.pub-title {
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.pub-venue {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

/* --- Projects Page --- */
.projects-page .page-description {
    font-size: 1.05rem;
    margin-bottom: var(--spacing-2xl);
    color: var(--color-text-secondary);
}

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

.project-card {
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--spacing-lg);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
    border-color: var(--color-accent);
    box-shadow: 0 2px 12px rgba(37, 99, 235, 0.08);
}

.project-card h3 {
    margin-bottom: var(--spacing-sm);
}

.project-card h3 a {
    color: var(--color-text);
    font-weight: 600;
}

.project-card h3 a:hover {
    color: var(--color-accent);
}

.project-card p {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.project-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 500;
    padding: 3px 10px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    color: var(--color-text-secondary);
    margin-right: var(--spacing-xs);
    margin-bottom: var(--spacing-xs);
}

/* --- CV Page --- */
.cv-page h1 {
    margin-bottom: var(--spacing-2xl);
}

.cv-section {
    margin-bottom: var(--spacing-2xl);
}

.cv-section h2 {
    margin-top: 0;
    font-size: 1.15rem;
}

.cv-item {
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
}

.cv-item:last-child {
    border-bottom: none;
}

.cv-item h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.cv-meta {
    font-size: 0.88rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.cv-item ul {
    padding-left: var(--spacing-lg);
}

.cv-item li {
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.cv-section > p {
    font-size: 0.9rem;
}

/* --- 404 Page --- */
.not-found {
    text-align: center;
    padding: var(--spacing-3xl) 0;
}

.not-found h1 {
    font-size: 4rem;
    color: var(--color-border);
    margin-bottom: var(--spacing-md);
}

.not-found p {
    font-size: 1.05rem;
}

.not-found a {
    font-weight: 600;
}

/* --- Footer --- */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

.footer-links {
    display: flex;
    gap: var(--spacing-md);
}

.footer-links a {
    color: var(--color-text-secondary);
    font-weight: 500;
}

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

/* --- Responsive --- */
@media (max-width: 640px) {
    .site-header .container {
        flex-wrap: wrap;
    }

    .mobile-toggle {
        display: flex;
    }

    .site-nav {
        display: none;
        width: 100%;
        padding-top: var(--spacing-md);
    }

    .site-nav.open {
        display: block;
    }

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

    .site-nav ul li a {
        padding: var(--spacing-sm) 0;
    }

    .site-main {
        padding: var(--spacing-2xl) 0;
    }

    .site-main h1 {
        font-size: 1.6rem;
    }

    .hero-section h1 {
        font-size: 1.8rem;
    }

    .quick-links {
        flex-direction: column;
    }

    .quick-links .btn {
        text-align: center;
    }

    .footer-content {
        flex-direction: column;
        gap: var(--spacing-md);
        text-align: center;
    }

    .project-card {
        padding: var(--spacing-md);
    }
}

@media (min-width: 641px) {
    .project-grid {
        grid-template-columns: 1fr 1fr;
    }
}