html {
  scroll-behavior: smooth;
}


:root {
  --bg: #ffffff;
  --text: #222222;
  --muted: #3a3a3a;
  --code-bg: #f6f6f6;
  --code-border: #e1e1e1;

  /* FONTS */
  --font-serif: "source-serif-pro", serif;
--font-sans: "proxima-nova", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}


/* PAGE + BASE */
html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-serif);     /* SERIF BODY (YOUR REQUEST) */
  font-weight: 450;                   /* slightly heavier body */
  line-height: 1.74;                  /* article-like */
  overflow-x: hidden;
}

.sans {
  font-family: var(--font-sans) !important;
}

.serif {
  font-family: var(--font-serif) !important;
}


/* MAIN LAYOUT */
main {
  width: 900px;
  max-width: 100%;
  margin-left: auto;
  margin-right: auto;
  padding: 3rem 1.5rem 4rem;
  box-sizing: border-box;
  overflow-x: hidden;
}

/* PARAGRAPHS */
p {
  font-family: var(--font-serif);     /* ensure serif */
  font-size: 1.06rem;
  color: var(--muted);
  margin: 0 0 1.4rem;
  font-weight: 450;
}

/* HEADINGS (SANS-SERIF) */
h1, h2, h3, h4 {
  font-family: var(--font-sans);      /* SANS HEADINGS (your request) */
  font-weight: 700;                   /* slightly bolder */
  letter-spacing: -0.01em;
  color: #222;
  margin: 0 0 0.75rem;
}

/* CASE STUDY MAIN TITLE */
.cs-title h1 {
  margin: 0;
  padding: 0;
  font-size: 2.4rem;
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.01em;
}


/* SUBTITLE */
.case-study-header h2 {
  font-size: 1.36rem;
  font-weight: 700;        /* ← true bold */
  margin: 0.25rem 0 1.1rem;
  max-width: 60ch;
}

.case-study-header h1 {
  font-size: 1.86rem;
  font-weight: 700;        /* ← true bold */
  margin: 0.25rem 0 1.1rem;
  max-width: 60ch;
}

/* FIGURE + CAPTION STYLING */
.cs-figure {
  margin: 2.2rem auto;
  text-align: center;
}

.cs-figure img {
  display: block;
  margin: 0 auto 0.8rem;
  max-width: 100%;
  height: auto;
}

.cs-figure figcaption {
  font-family: var(--font-serif);     /* matches article body text */
  font-size: 0.92rem;
  color: #666;
  letter-spacing: 0.01em;
  margin-top: 0.3rem;
  line-height: 1.5;
}


/* SECTION HEADERS */
h2 {
  font-size: 1.32rem;
  margin-top: 3rem;
}

h3 {
  font-size: 1.12rem;
  margin-top: 2.1rem;
}

/* LISTS */
ul, ol {
  font-family: var(--font-serif);
  font-weight: 450;
}

/* INLINE CODE */
p code,
li code {
  font-family: var(--font-mono);
  background: #f0f0f0;
  border: 1px solid #e2e2e2;
  padding: 0.12em 0.35em;
  border-radius: 4px;
  font-size: 0.88em;
  color: #343434;
}

/* CODE BLOCKS */
pre {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  padding: 1rem 1.3rem;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.96rem;
  margin: 1.7rem 0;
}

pre code {
  font-family: var(--font-mono);
  background: none;
  padding: 0;
  border: none;
}

/* IMAGES */
img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 2rem auto;
}

/* KEEP CONTENT INSIDE COLUMN */
main * {
  max-width: 100%;
  box-sizing: border-box;
}

/* GRID FOR DATA FIELDS */


.field {
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--muted);
  line-height: 1.45;
}

.field strong {
  font-family: var(--font-sans);
  font-weight: 650;
  color: #222;
  display: block;
  margin-bottom: 0.15rem;
}

.fields-grid {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 1.3rem 1.5rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.2rem 1rem;
  width: 100%;
  margin: 1.5rem 0 2rem;
  box-sizing: border-box;
  font-size: 0.9rem;  /* optional: if you still want smaller text */
}




.json-block {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 1rem 1.3rem;
  max-height: 380px;
  overflow-x: auto;
  overflow-y: auto;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  white-space: pre;
  margin: 1.5rem 0 2rem;
}

/* Python comment color */
.token.comment,
.token.prolog,
.token.doctype,
.token.cdata {
  color: #949393 !important;   /* deep maroon/burgundy */
  font-style: normal;
}

.code-output-table {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 6px;
  padding: 0.3rem 0.9rem;   /* small top padding */
  font-family: var(--font-mono);
  font-size: 0.9rem;
   margin: 0.3rem 0.6rem 0.25rem 0; 

  display: inline-block;
}


.code-output-table table {
  border-collapse: collapse;
}

.code-output-table th,
.code-output-table td {
  padding: 2px 12px;
  text-align: left;
  white-space: pre;                            /* keeps monospace alignment */
  border: none;                                /* no borders */
}

.table-caption {
  font-family: var(--font-serif);
  font-size: 0.92rem;
  color: #666;
  margin: 0.2rem 0 0.6rem;  /* small gap above & below */
  line-height: 1.2;         /* no tall vertical gap */
}



.case-summary-grid {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  padding: 1rem 1.5rem;
  border-radius: 6px;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(4, 1fr);
  font-size: 0.95rem;
  margin-bottom: 2rem;
}

.download-data a {
  font-family: var(--font-sans);
  font-size: 1rem;
  text-decoration: underline;
  color: #222;               /* neutral dark text */
  text-underline-offset: 3px;
  text-decoration-thickness: 1.5px;
  cursor: pointer;
}

.download-data a:hover {
  color: #000;               /* slightly darker on hover */
  text-decoration-thickness: 2px;
}

#reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 0;
  background: #ffe601;
  z-index: 9999;
  transition: width 0.1s linear;
}

.section-divider {
  width: 100%;
  height: 1px;
  background: #e8e8e8;
  margin: 3.5rem 0 2.5rem;
}

.toc {
  position: fixed;
  top: 120px;
  right: 40px;
  width: 180px;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  line-height: 1.5;
}
.toc h4 {
  font-weight: 700;
  margin-bottom: 0.5rem;
}
.toc ul {
  list-style: none;
  padding-left: 0;
}
.toc li {
  margin-bottom: 0.4rem;
}
.toc a {
  color: #666;
  text-decoration: none;
}
.toc a:hover {
  color: #000;
}
@media (max-width: 1100px) {
  .toc { display: none; }
}

/* Add spacing when jumping to sections via #anchor links */
h1[id], h2[id], h3[id], h4[id] {
  scroll-margin-top: 120px;   /* adjust number for more/less space */
}

pre code,
code[class*="language-"] {
  font-family: "JetBrains Mono", "Fira Code", monospace !important;
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0;
}

.token.operator {
  background: none !important;
}

.summary-card {
  background: #fafafa;
  border: 1px solid #e5e5e5;
  padding: 2rem;
  border-radius: 8px;
  margin-top: 3rem;
  font-size: 1rem;
  line-height: 1.6;
}
.summary-card strong {
  font-family: var(--font-sans);
  font-weight: 700;
  color: #222;
}

/* ===== SIMPLE HEADER FOR CASE STUDY (MATCH WIDTH) ===== */

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

  /* MATCH MAIN SITE WIDTH */
  max-width: 1300px;
  width: 100%;
  margin: 0 auto;
  padding: 16px 16px 0;

  background: transparent;
  border: none;
  box-shadow: none;
  position: static;
  box-sizing: border-box;
}

.left-header {
  display: flex;
  align-items: center;
}

.head-name {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* inline links, no header bar */
.top-nav {
  display: flex;
  gap: 1.75rem;
}

.top-nav a {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  text-decoration: none;
  color: #333;
  padding-bottom: 4px;
}

.top-nav a:hover,
.top-nav a:focus {
  color: #1a73e8;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 2px;
}

.top-nav a[aria-current="page"] {
  color: #1a73e8;
}

/* ===== MOBILE ===== */

.hamburger {
  display: none;
  width: 40px;
  height: 36px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 0;
}

.hamburger span {
  display: block;
  height: 4px;
  width: 27px;
  background: #333;
  margin: 4px 0;
  border-radius: 2px;
  transition: 0.3s;
}

@media (max-width: 760px) {
  .hamburger { display: block; }

  .header {
    padding: 12px 16px;
  }

  .top-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    max-width: 900px;                 /* ⭐ matches width on mobile drop */
    width: 100%;
    margin: 0 auto;

    background: #fff;
    border-top: 1px solid #eee;
    display: flex;
    flex-direction: column;
    gap: 10px;

    padding: 16px;
    max-height: 0;
    opacity: 0;
    pointer-events: none;
    overflow: hidden;

    transition: max-height 260ms ease, opacity 180ms ease;
  }

  .top-nav.open {
    max-height: 240px;
    opacity: 1;
    pointer-events: auto;
  }
}

/* ===== DESKTOP ENSURE NO BAR ===== */
@media (min-width: 761px) {
  .header {
    background: transparent;
    box-shadow: none;
    position: static;
  }
}

.toc a.active {
  color: #000 !important;
}

/* =========================
   HAMBURGER NAVIGATION
   ========================= */

.hamburger {
  display: none;            /* hidden on desktop */
  width: 40px;
  height: 36px;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

.hamburger span {
  display: block;
  height: 4px;      /* thickness */
  width: 27px;      /* length */
  background: #333; /* color of bars */
  margin: 4px 0;
  border-radius: 2px;
  transition: 0.4s;
}

/* mobile nav animation hook */
.top-nav {
  transition: max-height 240ms ease, opacity 180ms ease;
  will-change: max-height, opacity;
}

/* =====================================
   MOBILE LAYOUT (≤ 760px)
   ===================================== */
@media (max-width: 760px) {

  .hamburger { display: inline-block; }

  .header {
    position: relative;
    padding: 16px 20px;
  }

  /* collapsed by default */
  .top-nav {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;

    background: #fff;
    border-top: 1px solid #eee;
    display: flex;
    flex-direction: column;
    gap: 8px;

    padding: 12px 16px;

    max-height: 0;
    opacity: 0;
    overflow: hidden;
    pointer-events: none;
  }

  .top-nav.open {
    max-height: 240px;
    opacity: 1;
    pointer-events: auto;
  }

  .top-nav a {
    padding: 10px 6px;
    font-size: 16px;
  }
}

@media (max-width: 760px) {
  h1, h2, h3, .cs-heading, .pf-lefttitle, .section-title {
    line-height: 1.05 !important;
  }
}

/* CENTER ALL CASE-STUDY PAGES ON MOBILE */
@media (max-width: 760px) {
  .case-study-page {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .case-study-page .cs1-container,
  .case-study-page main,
  .case-study-page section,
  .case-study-page .container {
    width: 100%;
    max-width: 800px;   /* or 1000px if your desktop width is bigger */
    padding-left: 16px;
    padding-right: 16px;
    margin-left: auto;
    margin-right: auto;
    box-sizing: border-box;
  }
}

/* Dataset fields grid – make it scroll nicely on small screens */
.data-fields {
  margin-top: 1.5rem;
}

/* desktop / normal */
.data-fields .fields-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(140px, 1fr));
  gap: 12px 24px;
}

/* horizontal scroll on mobile */
@media (max-width: 760px) {
  .data-fields {
    overflow-x: auto;
  }

  .data-fields .fields-grid {
    display: inline-flex;
    flex-wrap: nowrap;
    gap: 12px;
    min-width: max-content;   /* makes the content wider than the box */
  }

  .data-fields .field {
    min-width: 140px;
  }
}

.cs-video {
  max-width: 900px;
  margin: 60px auto;
  text-align: center;
}

.cs-video video {
  width: 100%;
  border-radius: 12px;
  display: block;
  object-fit: cover;
}