/* ========================================
   Sarthak Joshi — Academic Website
   sarthakjoshi.net
   ======================================== */

@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,300;0,8..60,400;0,8..60,600;1,8..60,400&family=DM+Sans:wght@400;500;600&display=swap');

:root {
  --color-bg: #faf9f7;
  --color-text: #2c2c2c;
  --color-text-secondary: #5a5a5a;
  --color-accent: #1a4a6e;
  --color-accent-hover: #0d3450;
  --color-border: #e0ddd8;
  --color-surface: #f0eee9;
  --color-tag-bg: #e8e4de;
  --font-serif: 'Source Serif 4', Georgia, serif;
  --font-sans: 'DM Sans', system-ui, sans-serif;
  --max-width: 740px;
  --spacing-page: 2rem;
}

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

html {
  font-size: 17px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}
a:hover {
  border-bottom-color: var(--color-accent);
}

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

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.2rem var(--spacing-page);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 2rem;
}

.site-name {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--color-text);
  letter-spacing: -0.01em;
  border-bottom: none;
  white-space: nowrap;
}
.site-name:hover { border-bottom: none; }

nav { display: flex; gap: 1.6rem; flex-wrap: wrap; }

nav a {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-bottom: 2px solid transparent;
  padding-bottom: 2px;
  transition: color 0.2s, border-color 0.2s;
}
nav a:hover,
nav a.active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

/* --- Main content --- */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem var(--spacing-page) 4rem;
  flex: 1;
  width: 100%;
}

/* --- Page title --- */
h1 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 2rem;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 1.5rem;
  color: var(--color-text);
}

h2 {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  margin-top: 2.8rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
}

h3 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 1.05rem;
  line-height: 1.4;
  margin-bottom: 0.3rem;
}

p { margin-bottom: 1rem; }

/* --- Home page layout --- */
.home-intro {
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
}

.home-photo {
  width: 180px;
  min-width: 180px;
  border-radius: 6px;
  object-fit: cover;
  filter: grayscale(10%);
}

.home-text p {
  font-family: var(--font-serif);
  font-size: 1.08rem;
  color: var(--color-text);
}

.home-text a {
  font-weight: 500;
}

.contact-line {
  margin-top: 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.92rem;
  color: var(--color-text-secondary);
}

/* --- Research items --- */
.paper {
  margin-bottom: 2.2rem;
}

.paper h3 {
  margin-bottom: 0.25rem;
}

.paper-coauthors {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.35rem;
}

.paper-links {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.paper-links a {
  font-size: 0.82rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-accent);
  background: var(--color-surface);
  padding: 0.2em 0.6em;
  border-radius: 3px;
  border-bottom: none;
  transition: background 0.2s;
}
.paper-links a:hover {
  background: var(--color-tag-bg);
  border-bottom: none;
}

.paper-status {
  font-size: 0.85rem;
  font-style: italic;
  color: var(--color-text-secondary);
  margin-bottom: 0.4rem;
}

.paper-abstract {
  font-size: 0.92rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* --- Teaching --- */
.course {
  margin-bottom: 1.8rem;
}

.course h3 {
  margin-bottom: 0.15rem;
}

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

.testimonial {
  margin: 1.2rem 0;
  padding-left: 1.2rem;
  border-left: 3px solid var(--color-border);
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.testimonial cite {
  display: block;
  margin-top: 0.4rem;
  font-style: normal;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--color-text-secondary);
}

/* --- CV page --- */
.cv-download {
  font-family: var(--font-serif);
  font-size: 1.05rem;
}

/* --- Footer --- */
footer {
  border-top: 1px solid var(--color-border);
  padding: 1.5rem var(--spacing-page);
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  letter-spacing: 0.02em;
}

/* --- Responsive --- */
@media (max-width: 600px) {
  html { font-size: 16px; }

  .header-inner {
    flex-direction: column;
    gap: 0.8rem;
    padding: 1rem var(--spacing-page);
  }

  nav { gap: 1.2rem; }

  .home-intro {
    flex-direction: column;
    gap: 1.5rem;
  }

  .home-photo {
    width: 140px;
    min-width: auto;
  }

  main { padding: 1.8rem var(--spacing-page) 3rem; }
}