/* =============================================================
   Vishwas Sathish — Academic Website Styles
   ============================================================= */

/* --- Variables --- */
:root {
  --primary:        #4b2e83;
  --primary-dark:   #3a2369;
  --primary-light:  #ede9f5;
  --gold:           #b7a57a;
  --text:           #1a1a1a;
  --text-muted:     #555565;
  --text-light:     #909099;
  --bg:             #ffffff;
  --bg-alt:         #f7f8fb;
  --border:         #e3e3ec;
  --radius:         6px;
  --shadow:         0 1px 4px rgba(0,0,0,0.06), 0 3px 14px rgba(0,0,0,0.04);
  --max-w:          960px;
  --nav-h:          56px;
  --font:           -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono:      "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --tr:             0.17s ease;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
img, video { max-width: 100%; height: auto; display: block; }
button, input, textarea, select { font: inherit; }

/* --- Base --- */
body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.72;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); text-decoration: underline; }
strong { font-weight: 600; }

h1 { font-size: 2rem;   font-weight: 700; line-height: 1.2; }
h2 { font-size: 1.45rem; font-weight: 700; line-height: 1.3; }
h3 { font-size: 1.1rem;  font-weight: 600; line-height: 1.4; }
h4 { font-size: 1rem;    font-weight: 600; }

p { margin-bottom: 1rem; }
p:last-child { margin-bottom: 0; }

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--bg-alt);
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid var(--border);
}
pre { background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--radius); padding: 1rem; overflow-x: auto; margin: 1rem 0; }
pre code { background: none; border: none; padding: 0; font-size: 0.85em; }

hr { border: none; border-top: 1px solid var(--border); margin: 2.5rem 0; }

/* --- Layout --- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.page-content {
  padding-top: calc(var(--nav-h) + 2.25rem);
  padding-bottom: 5rem;
  min-height: 100vh;
}

/* --- Navigation --- */
#site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 200;
  transition: box-shadow var(--tr);
}
#site-header.scrolled { box-shadow: 0 2px 18px rgba(0,0,0,0.06); }

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-h);
}

.nav-logo {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
  flex-shrink: 0;
}
.nav-logo:hover { color: var(--primary); text-decoration: none; }

.nav-links {
  list-style: none;
  display: flex;
  gap: 0.1rem;
}
.nav-links a {
  display: block;
  padding: 0.3rem 0.7rem;
  border-radius: 4px;
  font-size: 0.88rem;
  color: var(--text-muted);
  font-weight: 500;
  transition: color var(--tr), background var(--tr);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
  background: var(--primary-light);
  text-decoration: none;
}

/* Hamburger */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.45rem;
  color: var(--text);
  border-radius: 4px;
  transition: background var(--tr);
}
.nav-toggle:hover { background: var(--bg-alt); }
.nav-toggle svg { display: block; }

@media (max-width: 680px) {
  .nav-toggle { display: flex; align-items: center; }
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-h);
    left: 0; right: 0;
    background: white;
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 0.6rem 1.25rem 1rem;
    gap: 0;
    box-shadow: 0 6px 20px rgba(0,0,0,0.07);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: 0.6rem 0.25rem;
    border-radius: 0;
    border-bottom: 1px solid var(--border);
    font-size: 0.95rem;
  }
  .nav-links li:last-child a { border-bottom: none; }
}

/* --- Profile --- */
.profile-section { padding: 2.75rem 0 2.5rem; }

.profile-grid {
  display: grid;
  grid-template-columns: 1fr 195px;
  gap: 3rem;
  align-items: start;
}

.profile-name {
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.2rem;
  color: var(--text);
}

.profile-affil {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.25rem;
}
.profile-affil a { color: var(--text-muted); font-weight: 500; }
.profile-affil a:hover { color: var(--primary); }

.profile-bio p { font-size: 0.95rem; margin-bottom: 0.85rem; }

.interests {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 1rem 0 1.25rem;
}
.interest-chip {
  font-size: 0.77rem;
  padding: 0.22rem 0.65rem;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 100px;
  font-weight: 500;
  letter-spacing: 0.01em;
}

.profile-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.25rem;
}
.profile-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.35rem 0.8rem;
  border: 1.5px solid var(--border);
  border-radius: 100px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text);
  text-decoration: none;
  transition: border-color var(--tr), color var(--tr), background var(--tr);
}
.profile-link:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
  text-decoration: none;
}

.profile-photo-wrap { display: flex; justify-content: center; }
.profile-photo {
  width: 185px;
  height: 185px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
  box-shadow: 0 2px 14px rgba(0,0,0,0.08);
  transition: box-shadow var(--tr);
}
.profile-photo:hover { box-shadow: 0 4px 22px rgba(75,46,131,0.15); }

@media (max-width: 680px) {
  .profile-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .profile-photo-wrap { order: -1; }
  .profile-photo { width: 120px; height: 120px; }
}

/* --- Section headers --- */
.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--primary-light);
}

.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
}
.section-title::before {
  content: '';
  display: inline-block;
  width: 3.5px;
  height: 0.95em;
  background: var(--primary);
  border-radius: 2px;
  margin-right: 0.55rem;
  vertical-align: middle;
  transform: translateY(-1px);
}

.section-link {
  font-size: 0.83rem;
  color: var(--text-muted);
  transition: color var(--tr);
}
.section-link:hover { color: var(--primary); text-decoration: none; }

.page-section { margin-bottom: 3rem; }

/* --- Page intro --- */
.page-intro {
  font-size: 0.97rem;
  color: var(--text-muted);
  max-width: 680px;
  margin-bottom: 2rem;
  line-height: 1.75;
}

/* --- News --- */
.news-list { list-style: none; }
.news-item {
  display: grid;
  grid-template-columns: 95px 1fr;
  gap: 1rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.91rem;
  line-height: 1.6;
}
.news-item:last-child { border-bottom: none; }
.news-date {
  color: var(--text-light);
  font-size: 0.79rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding-top: 0.15rem;
  flex-shrink: 0;
}
.news-text a { color: var(--primary); }

/* --- Publications --- */
.pub-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.pub-card {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 1.25rem;
  padding: 1.25rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: box-shadow var(--tr), border-color var(--tr);
}
.pub-card:hover { box-shadow: var(--shadow); border-color: #cccce0; }

.pub-thumb {
  width: 130px;
  height: 90px;
  object-fit: cover;
  border-radius: 4px;
  flex-shrink: 0;
}
.pub-thumb-placeholder {
  width: 130px;
  height: 90px;
  background: linear-gradient(135deg, var(--primary-light) 0%, #ddd8f0 100%);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.6rem;
  flex-shrink: 0;
}

.pub-content { min-width: 0; }

.pub-title {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.4;
  margin-bottom: 0.3rem;
}
.pub-title a { color: var(--text); }
.pub-title a:hover { color: var(--primary); text-decoration: none; }

.pub-authors {
  font-size: 0.84rem;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}
.pub-venue {
  font-size: 0.84rem;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 0.45rem;
}
.pub-summary {
  font-size: 0.84rem;
  color: var(--text-muted);
  line-height: 1.57;
  margin-bottom: 0.6rem;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.4rem;
}
.pub-link {
  display: inline-block;
  padding: 0.18rem 0.6rem;
  font-size: 0.76rem;
  font-weight: 600;
  border-radius: 3px;
  background: var(--primary-light);
  color: var(--primary);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background var(--tr), color var(--tr);
}
.pub-link:hover {
  background: var(--primary);
  color: white;
  text-decoration: none;
}

/* Badges */
.pub-badge {
  display: inline-block;
  padding: 0.08rem 0.5rem;
  font-size: 0.7rem;
  font-weight: 700;
  border-radius: 3px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-left: 0.5rem;
  vertical-align: middle;
}
.badge-selected    { background: #fdf0cf; color: #7a5910; border: 1px solid #e8d080; }
.badge-workshop    { background: #d4edda; color: #155724; border: 1px solid #b8dfc5; }
.badge-preprint    { background: #d1ecf1; color: #0c5460; border: 1px solid #a0d6df; }
.badge-patent      { background: #e9ecef; color: #495057; border: 1px solid #ced4da; }
.badge-in-submission { background: #fff3cd; color: #856404; border: 1px solid #f0d060; }
.badge-report      { background: #e8f4f8; color: #2c5f7a; border: 1px solid #b0d8ec; }

@media (max-width: 580px) {
  .pub-card { grid-template-columns: 1fr; }
  .pub-thumb, .pub-thumb-placeholder { width: 100%; height: 160px; }
}

/* --- Publication filter tabs --- */
.pub-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 2rem;
}
.pub-tab {
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 100px;
  padding: 0.3rem 0.9rem;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-muted);
  transition: all var(--tr);
}
.pub-tab:hover,
.pub-tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

/* --- Projects --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 1.2rem;
}

.project-card {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  transition: box-shadow var(--tr), border-color var(--tr), transform 0.2s ease;
}
.project-card:hover {
  box-shadow: var(--shadow);
  border-color: #c8c8e0;
  transform: translateY(-2px);
}
.project-thumb {
  width: 100%;
  height: 155px;
  object-fit: cover;
  border-radius: 4px;
  margin-bottom: 0.5rem;
  background: var(--border);
}
.project-type {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--primary);
}
.project-title {
  font-size: 0.97rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}
.project-desc {
  font-size: 0.86rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex: 1;
}
.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.5rem;
}
.project-link {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  font-size: 0.76rem;
  font-weight: 600;
  border-radius: 3px;
  background: var(--primary-light);
  color: var(--primary);
  text-decoration: none;
  border: 1px solid transparent;
  transition: background var(--tr), color var(--tr);
}
.project-link:hover {
  background: var(--primary);
  color: white;
  text-decoration: none;
}

/* --- Writing list --- */
.writing-list { list-style: none; }
.writing-item {
  padding: 1.2rem 0;
  border-bottom: 1px solid var(--border);
}
.writing-item:first-child { border-top: 1px solid var(--border); }
.writing-meta {
  font-size: 0.8rem;
  color: var(--text-light);
  margin-bottom: 0.2rem;
  display: flex;
  gap: 0.6rem;
  align-items: center;
  flex-wrap: wrap;
}
.writing-tag {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 0.04rem 0.5rem;
  font-size: 0.72rem;
  color: var(--text-muted);
}
.writing-title { font-size: 1.02rem; font-weight: 600; }
.writing-title a { color: var(--text); }
.writing-title a:hover { color: var(--primary); }
.writing-summary { font-size: 0.87rem; color: var(--text-muted); margin-top: 0.25rem; }

/* --- Post / Writing page --- */
.post-header { margin-bottom: 2.5rem; }
.post-title {
  font-size: 1.85rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.55rem;
}
.post-meta {
  font-size: 0.84rem;
  color: var(--text-light);
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.post-body { max-width: 680px; }
.post-body h2 { font-size: 1.3rem; margin: 2rem 0 0.7rem; }
.post-body h3 { font-size: 1.07rem; margin: 1.5rem 0 0.5rem; }
.post-body p { margin-bottom: 1.05rem; }
.post-body ul, .post-body ol { padding-left: 1.5rem; margin-bottom: 1rem; }
.post-body li { margin-bottom: 0.3rem; }
.post-body blockquote {
  border-left: 3px solid var(--primary);
  padding: 0.5rem 1rem;
  color: var(--text-muted);
  background: var(--bg-alt);
  border-radius: 0 4px 4px 0;
  margin: 1.25rem 0;
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.87rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}
.back-link:hover { color: var(--primary); text-decoration: none; }

/* --- CV page --- */
.cv-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.15rem;
  background: var(--primary);
  color: white;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.88rem;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: background var(--tr);
}
.btn-primary:hover { background: var(--primary-dark); color: white; text-decoration: none; }
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.53rem 1.1rem;
  background: none;
  color: var(--primary);
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.88rem;
  text-decoration: none;
  border: 1.5px solid var(--primary);
  transition: all var(--tr);
}
.btn-secondary:hover { background: var(--primary-light); text-decoration: none; }

.cv-embed-wrapper {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 2.5rem;
  background: var(--bg-alt);
}
.cv-embed {
  display: block;
  width: 100%;
  min-height: 820px;
  border: none;
}
.cv-fallback {
  padding: 3rem 2rem;
  text-align: center;
  display: none;
}
.cv-fallback p { color: var(--text-muted); margin-bottom: 1rem; }

.experience-list { list-style: none; }
.experience-item {
  display: grid;
  grid-template-columns: 135px 1fr;
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.9rem;
}
.experience-item:last-child { border-bottom: none; }
.exp-years {
  font-size: 0.8rem;
  color: var(--text-light);
  font-weight: 600;
  letter-spacing: 0.02em;
  padding-top: 0.1rem;
}
.exp-role { font-weight: 600; margin-bottom: 0.1rem; }
.exp-org { color: var(--text-muted); font-size: 0.85rem; }

@media (max-width: 580px) {
  .experience-item { grid-template-columns: 1fr; gap: 0.2rem; }
  .exp-years { padding-top: 0; }
}

/* --- Art --- */
.art-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}
.art-item {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: box-shadow var(--tr);
}
.art-item:hover { box-shadow: var(--shadow); }
.art-item img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  display: block;
  transition: opacity 0.2s;
}
.art-item:hover img { opacity: 0.88; }
.art-caption {
  padding: 0.6rem 0.8rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
}

/* --- Page header (for interior pages) --- */
.page-header { margin-bottom: 2.25rem; }
.page-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 0.5rem;
}

/* --- Show more button --- */
.show-more-btn {
  background: none;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 0.5rem 1.25rem;
  font-size: 0.87rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-muted);
  display: block;
  margin: 1.5rem auto 0;
  transition: all var(--tr);
}
.show-more-btn:hover { border-color: var(--primary); color: var(--primary); }

/* --- Utilities --- */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  margin: -1px; padding: 0; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.75rem; }

/* --- Footer --- */
#site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-light);
}
#site-footer a { color: var(--text-muted); }
#site-footer a:hover { color: var(--primary); }

/* --- Loading placeholder --- */
.loading-placeholder { color: var(--text-light); font-size: 0.9rem; font-style: italic; }

/* --- Print --- */
@media print {
  #site-header, #site-footer { display: none; }
  .page-content { padding-top: 0; }
  a { color: var(--text); text-decoration: underline; }
}