/* ═══════════════════════════════════════════
   Sahyadri — Shared Stylesheet
   ═══════════════════════════════════════════ */

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

:root {
  --bg:            #faf9f6;
  --bg-card:       #ffffff;
  --bg-code:       #f3f1ed;
  --bg-nav:        rgba(250, 249, 246, 0.92);
  --accent:        #1a5f7a;
  --accent-light:  #e8f1f5;
  --accent-hover:  #134a5f;
  --text:          #1c1f26;
  --text-secondary:#4a4f5c;
  --text-muted:    #838894;
  --border:        #e2e0db;
  --border-light:  #eceae5;
  --green:         #2d7a4f;
  --green-bg:      #ecf5f0;
  --orange:        #b37318;
  --orange-bg:     #fdf3e3;
  --serif:  'Source Serif 4', Georgia, serif;
  --sans:   'IBM Plex Sans', -apple-system, sans-serif;
  --mono:   'IBM Plex Mono', 'Menlo', monospace;
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--accent-light); color: var(--accent); }
img { max-width: 100%; height: auto; display: block; }


.path-block{
  font-family:'IBM Plex Mono', monospace;
  font-size:.85rem;
  color:#2e3a8c;
  background:#eef0fb;
  border:1px solid #e4e7f0;
  border-radius:8px;
  padding:10px 14px;
  margin:8px 0 12px;
  overflow-x:auto;
  white-space:nowrap;   /* keep the path on one line; scroll on narrow screens */
}

/* ═══════ Navigation ═══════ */

.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: box-shadow 0.3s;
}
.nav.scrolled { box-shadow: 0 1px 12px rgba(0, 0, 0, 0.04); }

.nav-inner {
  max-width: 1100px; margin: 0 auto;
  padding: 0 28px; height: 56px;
  display: flex; align-items: center; justify-content: space-between;
}

.nav-logo {
  font-family: var(--serif); font-size: 18px; font-weight: 700;
  color: var(--text); text-decoration: none; letter-spacing: 0.5px;
}
.nav-logo span { color: var(--accent); }

.nav-links { display: flex; gap: 2px; align-items: center; }
.nav-links a {
  font-size: 13px; font-weight: 500; color: var(--text-muted);
  text-decoration: none; padding: 6px 12px; border-radius: 6px;
  transition: all 0.2s; white-space: nowrap;
}
.nav-links a:hover { color: var(--text); background: rgba(0, 0, 0, 0.03); }
.nav-links a.active { color: var(--accent); background: var(--accent-light); }

.nav-hamburger {
  display: none; background: none; border: none;
  font-size: 20px; color: var(--text); cursor: pointer;
  width: 40px; height: 40px;
  align-items: center; justify-content: center;
}

.mobile-menu {
  display: none;
  position: fixed; top: 56px; left: 0; right: 0;
  background: var(--bg); border-bottom: 1px solid var(--border);
  padding: 12px 20px 20px; z-index: 99;
}
.mobile-menu.open { display: block; }
.mobile-menu a {
  display: block; padding: 10px 12px; font-size: 15px;
  color: var(--text-secondary); text-decoration: none; border-radius: 6px;
}
.mobile-menu a:hover,
.mobile-menu a.active { color: var(--accent); background: var(--accent-light); }

@media (max-width: 860px) {
  .nav-links  { display: none !important; }
  .nav-hamburger { display: flex !important; }
}


/* ═══════ Layout ═══════ */
    .contact-grid{ display:grid; grid-template-columns:repeat(auto-fit,minmax(220px,1fr)); gap:18px; }
    .contact-grid .card{ display:flex; flex-direction:column; gap:6px; }
    .contact-aff{ color:#5c6376; font-size:.9rem; margin:0; }
    .contact-mail{ font-family:'IBM Plex Mono',monospace; font-size:.82rem; color:#5c6376; margin-top:auto; padding-top:8px; }
    .contact-link{ font-family:'IBM Plex Mono',monospace; font-size:.82rem; color:#2e3a8c;
                   text-decoration:none; word-break:break-all; margin-top:auto; padding-top:8px; }
    .contact-link:hover{ text-decoration:underline; }



.page-wrapper { padding-top: 56px; }

.section {
  max-width: 960px; margin: 0 auto;
  padding: 56px 28px;
}

.section-title {
  font-family: var(--serif);
  font-size: clamp(24px, 3.5vw, 34px);
  font-weight: 700; color: var(--text);
  line-height: 1.25; margin-bottom: 6px;
}

.section-sub {
  font-size: 15px; color: var(--text-secondary);
  max-width: 640px; line-height: 1.7; margin-bottom: 32px;
}

.note-block{
  background:#fdf4e0;
  border:1px solid #f0dcae;
  border-left:3px solid #9a6b12;
  border-radius:8px;
  padding:14px 16px;
  margin:16px 0;
}
.note-block .note-title{
  font-weight:600;
  font-size:.9rem;
  color:#9a6b12;
  margin:0 0 6px;
}
.note-block p{
  margin:0;
  font-size:.9rem;
  color:#5c6376;
}
.note-block code{
  font-family:'IBM Plex Mono', monospace;
  font-size:.85em;
}

.section-rule {
  display: block; width: 40px; height: 2px;
  background: var(--accent); border: none;
  margin: 14px 0 32px; border-radius: 1px;
}


/* ═══════ Cards ═══════ */

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 10px; padding: 24px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.card:hover {
  border-color: var(--border);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.03);
}
.card-flat { box-shadow: none; }
.card-flat:hover { box-shadow: none; border-color: var(--border-light); }

.card-accent {
  background: var(--accent-light);
  border-color: #c8dde6;
}
.card-warn {
  background: var(--orange-bg);
  border-color: #e8d5b4;
}

.card-title {
  font-family: var(--serif); font-size: 17px;
  font-weight: 600; color: var(--text);
  margin-bottom: 8px; line-height: 1.3;
}

.card-text {
  font-size: 14px; color: var(--text-secondary); line-height: 1.7;
}


/* ═══════ Grids ═══════ */

.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; }
.grid-6 { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 14px; }


/* ═══════ Tables ═══════ */

.spec-table { width: 100%; border-collapse: collapse; }
.spec-table td {
  padding: 10px 0; font-size: 14px;
  border-bottom: 1px solid var(--border-light);
}
.spec-table td:first-child { color: var(--text-secondary); }
.spec-table td:last-child {
  font-family: var(--mono); font-size: 13px;
  text-align: right; color: var(--text);
}


/* ═══════ Badges & Tags ═══════ */

.badge {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 10px; border-radius: 20px;
  font-size: 11px; font-weight: 600;
}
.badge-complete { background: var(--green-bg); color: var(--green); }
.badge-progress { background: var(--orange-bg); color: var(--orange); }
.badge-dot {
  width: 6px; height: 6px; border-radius: 50%; display: inline-block;
}
.badge-complete .badge-dot { background: var(--green); }
.badge-progress .badge-dot { background: var(--orange); }

.tag {
  display: inline-block; padding: 2px 8px; border-radius: 4px;
  background: var(--bg-code); color: var(--text-muted);
  font-size: 11px; font-family: var(--mono);
}


/* ═══════ Stat Row ═══════ */

.stats-row {
  display: flex; flex-wrap: wrap; justify-content: center;
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: 10px;
}
.stat-item { text-align: center; padding: 20px 24px; flex: 1; min-width: 130px; }
.stat-value {
  font-family: var(--mono);
  font-size: clamp(20px, 2.5vw, 28px);
  font-weight: 500; color: var(--accent);
}
.stat-value small { font-size: 0.55em; color: var(--text-muted); margin-left: 3px; }
.stat-label {
  font-size: 11px; color: var(--text-muted); margin-top: 4px;
  text-transform: uppercase; letter-spacing: 1.5px;
}


/* ═══════ Resolution Bars ═══════ */

.res-bar-wrap { margin-bottom: 14px; }
.res-bar-label {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 13px; margin-bottom: 4px;
}
.res-bar-label span:first-child { color: var(--text); }
.res-bar-label span:last-child  { font-family: var(--mono); font-size: 11px; color: var(--text-muted); }
.res-bar-track { height: 6px; background: var(--border-light); border-radius: 3px; overflow: hidden; }
.res-bar-fill  { height: 100%; border-radius: 3px; transition: width 0.8s ease; }


/* ═══════ Accordion ═══════ */

.accordion-item { margin-bottom: 4px; }

.accordion-btn {
  width: 100%; text-align: left;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px; padding: 14px 18px;
  cursor: pointer; font-size: 15px;
  font-family: var(--sans); font-weight: 500; color: var(--text);
  display: flex; justify-content: space-between; align-items: center;
  transition: all 0.2s;
}
.accordion-btn:hover { border-color: var(--border); }
.accordion-btn.open {
  border-color: var(--accent); color: var(--accent);
  border-radius: 8px 8px 0 0;
  border-bottom-color: var(--border-light);
}

.accordion-icon {
  font-size: 18px; transition: transform 0.2s; color: var(--text-muted);
}
.accordion-btn.open .accordion-icon {
  transform: rotate(45deg); color: var(--accent);
}

.accordion-body {
  display: none; background: var(--bg-card);
  border: 1px solid var(--border-light); border-top: none;
  border-radius: 0 0 8px 8px; padding: 18px 18px 22px;
}
.accordion-body.open { display: block; }
.accordion-body p {
  font-size: 14px; color: var(--text-secondary);
  line-height: 1.8; margin-bottom: 12px;
}
.accordion-body p:last-child { margin-bottom: 0; }


/* ═══════ Code Block ═══════ */

.code-block {
  background: var(--bg-code);
  border: 1px solid var(--border-light);
  border-radius: 8px; padding: 20px;
  overflow-x: auto;
  font-family: var(--mono); font-size: 13px;
  line-height: 2; color: var(--text-secondary);
  white-space: pre;
}
.code-block .comment { color: var(--text-muted); }
.code-block .kw      { color: #7c3aed; }
.code-block .str     { color: var(--green); }
.code-block .num     { color: var(--orange); }
.code-block .fn      { color: var(--accent); }


/* ═══════ Image Slider ═══════ */

.viz-slider-wrap { max-width: 520px; margin: 0 auto; }

.viz-img-container {
  width: 100%; aspect-ratio: 1;
  border-radius: 8px; border: 1px solid var(--border-light);
  overflow: hidden; background: #f5f4f0;
  position: relative;
}
.viz-img-container img {
  width: 100%; height: 100%; object-fit: cover;
  position: absolute; top: 0; left: 0;
  opacity: 0; transition: opacity 0.35s ease;
}
.viz-img-container img.active { opacity: 1; }

.viz-controls {
  display: flex; align-items: center; gap: 12px;
  margin-top: 12px;
}
.viz-controls input[type=range] {
  flex: 1; -webkit-appearance: none; height: 3px;
  background: var(--border); border-radius: 2px; outline: none;
}
.viz-controls input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 14px; height: 14px;
  border-radius: 50%; background: var(--accent); cursor: pointer;
}
.viz-label {
  font-family: var(--mono); font-size: 12px;
  color: var(--text-muted); white-space: nowrap;
}


/* ═══════ Schematic Charts ═══════ */

.chart-img {
  width: 100%; border-radius: 8px;
  border: 1px solid var(--border-light);
}
.chart-caption {
  font-size: 12px; color: var(--text-muted);
  margin-top: 8px; line-height: 1.6;
}


/* ═══════ Publications ═══════ */

.pub-card { padding: 18px 22px; }
.pub-title {
  font-family: var(--sans); font-size: 15px;
  font-weight: 600; color: var(--text);
  line-height: 1.4; margin-bottom: 4px;
}
.pub-authors { font-size: 13px; color: var(--text-secondary); margin-bottom: 6px; }
.pub-meta { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.pub-meta span { font-size: 12px; }
.pub-year    { font-family: var(--mono); color: var(--text-muted); }
.pub-journal { color: var(--accent); }
.pub-arxiv {
  font-family: var(--mono); font-size: 11px;
  padding: 2px 8px; background: var(--accent-light);
  color: var(--accent); border-radius: 4px;
}


/* ═══════ Category Labels ═══════ */

.cat-label { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.cat-bar   { width: 4px; height: 22px; border-radius: 2px; }
.cat-heading {
  font-family: var(--serif); font-size: 19px;
  font-weight: 600; color: var(--text);
}


/* ═══════ Highlight Icons ═══════ */

.highlight-icon {
  width: 36px; height: 36px; border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 600; margin-bottom: 12px;
  background: var(--accent-light); color: var(--accent);
  font-family: var(--mono);
}


/* ═══════ Science List ═══════ */

.science-list { list-style: none; padding: 0; }
.science-list li {
  font-size: 14px; color: var(--text-secondary);
  line-height: 2; padding-left: 16px; position: relative;
}
.science-list li::before {
  content: ''; position: absolute; left: 0; top: 11px;
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--border);
}


/* ═══════ Hero ═══════ */

.hero {
  min-height: calc(100vh - 56px);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  text-align: center; padding: 60px 28px;
}
.hero-kicker {
  font-size: 12px; letter-spacing: 4px; text-transform: uppercase;
  color: var(--text-muted); margin-bottom: 16px; font-weight: 500;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(48px, 8vw, 84px);
  font-weight: 700; color: var(--text);
  line-height: 1.05; letter-spacing: -1px;
}
.hero h1 span { color: var(--accent); }
.hero-desc {
  font-size: clamp(15px, 2vw, 18px); color: var(--text-secondary);
  max-width: 580px; line-height: 1.7; margin-top: 20px;
}
.hero-actions {
  display: flex; gap: 12px; margin-top: 32px;
  flex-wrap: wrap; justify-content: center;
}


/* ═══════ Buttons ═══════ */

.btn-primary {
  display: inline-block;
  background: var(--accent); color: #fff; border: none;
  padding: 11px 26px; border-radius: 7px;
  font-size: 14px; font-weight: 600; cursor: pointer;
  font-family: var(--sans); text-decoration: none;
  transition: background 0.2s;
}
.btn-primary:hover { background: var(--accent-hover); }

.btn-secondary {
  display: inline-block;
  background: transparent; border: 1px solid var(--border);
  color: var(--text); padding: 11px 26px; border-radius: 7px;
  font-size: 14px; font-weight: 500; cursor: pointer;
  font-family: var(--sans); text-decoration: none;
  transition: all 0.2s;
}
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }


/* ═══════ Cite Box ═══════ */

.cite-box {
  background: var(--accent-light); border: 1px solid #c8dde6;
  border-radius: 10px; padding: 24px;
}
.cite-box .code-block {
  background: rgba(255, 255, 255, 0.5);
  border-color: #c8dde6;
}


/* ═══════ Footer ═══════ */

.footer {
  border-top: 1px solid var(--border-light);
  padding: 36px 28px; text-align: center;
}
.footer-name {
  font-family: var(--serif); font-size: 16px;
  color: var(--text-secondary); margin-bottom: 6px;
}
.footer-desc {
  font-size: 12px; color: var(--text-muted);
  max-width: 440px; margin: 0 auto 12px; line-height: 1.6;
}
.footer-copy {
  font-family: var(--mono); font-size: 11px; color: var(--text-muted);
}


/* ═══════ Utility ═══════ */

.mt-16 { margin-top: 16px; }
.mt-20 { margin-top: 20px; }
.mt-32 { margin-top: 32px; }
.mt-40 { margin-top: 40px; }
.mt-48 { margin-top: 48px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }

.gap-stack > * + * { margin-top: 12px; }

.accent-text { color: var(--accent); }
.green-text  { color: var(--green); }
.orange-text { color: var(--orange); }
.muted-text  { color: var(--text-muted); }
.mono        { font-family: var(--mono); }
.text-strong { color: var(--text); font-weight: 600; }

.numbered-icon {
  width: 28px; height: 28px; border-radius: 6px; flex-shrink: 0;
  background: var(--accent-light);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--mono); font-size: 13px; color: var(--accent);
}

.param-symbol {
  font-family: var(--mono); font-size: 22px;
  font-weight: 500; color: var(--accent);
}

.mono-info {
  font-family: var(--mono); font-size: 13px;
  color: var(--text-secondary); line-height: 2.2;
}


/* ═══════ Animations ═══════ */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
.section { animation: fadeUp 0.4s ease both; }
.section:nth-child(2) { animation-delay: 0.05s; }
.section:nth-child(3) { animation-delay: 0.1s; }


/* ═══════ Print ═══════ */

@media print {
  .nav, .mobile-menu { display: none !important; }
  .page-wrapper { padding-top: 0 !important; }
}

/* ------------------------------------------------------------------
   Notebook call-to-action buttons ("Download notebook" / "Open in Colab")
   Used on data-products.html and the learning/getting-started page.

   Scoped under .nb-cta so it can't collide with other page styles.
   Drop this block into shared css/style.css once, or paste the whole
   <style> tag inline wherever you use .nb-cta if you'd rather keep pages
   self-contained.
------------------------------------------------------------------- */

.nb-cta {
  --nb-radius: 10px;
  --nb-border: #dfe3e8;
  --nb-github: #24292f;
  --nb-github-hover: #000000;
  --nb-colab-a: #f9ab00;
  --nb-colab-b: #e8710a;
  margin: 1.75rem 0;
  padding: 1.25rem 1.5rem;
  border: 1px solid var(--nb-border);
  border-radius: var(--nb-radius);
  background: #fafbfc;
}

.nb-cta-text {
  margin: 0 0 1rem 0;
  font-size: 0.97rem;
  line-height: 1.55;
  color: #3a3f47;
}

.nb-cta-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.nb-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1.05rem;
  border-radius: 999px;
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  line-height: 1;
  border: 1px solid transparent;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
  box-shadow: 0 1px 2px rgba(16, 24, 40, 0.06);
}

.nb-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 10px rgba(16, 24, 40, 0.12);
}

.nb-btn svg {
  width: 1.1em;
  height: 1.1em;
  flex: none;
}

/* "Download notebook" — GitHub-flavored, outlined */
.nb-btn-github {
  background: #ffffff;
  border-color: var(--nb-border);
  color: var(--nb-github);
}

.nb-btn-github:hover {
  background: var(--nb-github);
  color: #ffffff;
  border-color: var(--nb-github);
}

/* "Open in Colab" — filled, Colab-orange gradient */
.nb-btn-colab {
  background: linear-gradient(135deg, var(--nb-colab-a), var(--nb-colab-b));
  color: #ffffff;
}

.nb-btn-colab:hover {
  filter: brightness(1.05);
}

@media (max-width: 480px) {
  .nb-cta-buttons {
    flex-direction: column;
    align-items: stretch;
  }
  .nb-btn {
    justify-content: center;
  }
}