/* =========================================
   FIZZHOMELAB — Main Stylesheet
   Aesthetic: Lab notebook meets craft soda bar
   Fonts: DM Serif Display + IBM Plex Mono
   Palette: Deep slate, amber gold, fizz teal
   ========================================= */

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

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

:root {
  --slate-950: #0c1118;
  --slate-900: #111827;
  --slate-800: #1e2736;
  --slate-700: #2d3a4a;
  --slate-600: #3f5068;
  --slate-400: #8da3bc;
  --slate-200: #c8d8e8;
  --slate-100: #e8f0f8;
  --slate-50:  #f4f8fc;

  --amber-400: #f59e0b;
  --amber-300: #fbbf24;
  --amber-200: #fde68a;
  --amber-100: #fef3c7;

  --teal-500:  #14b8a6;
  --teal-400:  #2dd4bf;
  --teal-300:  #5eead4;
  --teal-100:  #ccfbf1;

  --bubble:    #e0f2fe;
  --white:     #ffffff;

  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'Source Serif 4', Georgia, serif;
  --font-mono:    'IBM Plex Mono', 'Courier New', monospace;

  --radius-sm: 4px;
  --radius:    8px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,.12), 0 1px 2px rgba(0,0,0,.08);
  --shadow:    0 4px 12px rgba(0,0,0,.15), 0 2px 4px rgba(0,0,0,.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,.18), 0 4px 12px rgba(0,0,0,.1);
  --shadow-amber: 0 4px 20px rgba(245,158,11,.25);
  --shadow-teal:  0 4px 20px rgba(20,184,166,.2);

  --max-width: 1160px;
  --content-width: 780px;
}

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

body {
  font-family: var(--font-body);
  background: var(--slate-50);
  color: var(--slate-900);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* --- TYPOGRAPHY --- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.2;
  color: var(--slate-950);
}

h1 { font-size: clamp(2rem, 4vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); margin: 2.2rem 0 1rem; }
h3 { font-size: clamp(1.15rem, 2vw, 1.45rem); margin: 1.8rem 0 .7rem; }
h4 { font-size: 1.1rem; margin: 1.4rem 0 .5rem; }

p { margin-bottom: 1.2rem; color: var(--slate-800); }
p:last-child { margin-bottom: 0; }

a { color: var(--teal-500); text-decoration: none; transition: color .2s; }
a:hover { color: var(--amber-400); }

strong { font-weight: 600; color: var(--slate-950); }
em { font-style: italic; }

ul, ol { padding-left: 1.5rem; margin-bottom: 1.2rem; }
li { margin-bottom: .5rem; color: var(--slate-800); }

code {
  font-family: var(--font-mono);
  font-size: .88em;
  background: var(--slate-800);
  color: var(--teal-300);
  padding: .15em .45em;
  border-radius: var(--radius-sm);
}

blockquote {
  border-left: 4px solid var(--amber-400);
  padding: .8rem 1.2rem;
  margin: 1.5rem 0;
  background: var(--amber-100);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--slate-700);
}

hr {
  border: none;
  border-top: 1px solid var(--slate-200);
  margin: 2.5rem 0;
}

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

/* --- HEADER / NAV --- */
#site-header {
  background: var(--slate-950);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 2px solid var(--amber-400);
  box-shadow: 0 2px 20px rgba(0,0,0,.4);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: .55rem;
  text-decoration: none;
}
.logo-bubble {
  width: 32px; height: 32px;
  background: linear-gradient(135deg, var(--teal-400), var(--teal-500));
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px;
  box-shadow: 0 0 12px rgba(45,212,191,.4);
  animation: bubblePulse 3s ease-in-out infinite;
}
@keyframes bubblePulse {
  0%,100% { transform: scale(1); box-shadow: 0 0 12px rgba(45,212,191,.4); }
  50%      { transform: scale(1.06); box-shadow: 0 0 20px rgba(45,212,191,.6); }
}
.logo-text {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--white);
  letter-spacing: -.01em;
}
.logo-text span { color: var(--amber-400); }

/* NAV */
#main-nav { display: flex; align-items: center; gap: .15rem; }
#main-nav a {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 500;
  color: var(--slate-200);
  padding: .45rem .8rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background .2s, color .2s;
  letter-spacing: .02em;
  text-transform: uppercase;
}
#main-nav a:hover,
#main-nav a.active {
  background: var(--slate-800);
  color: var(--amber-400);
}
.nav-cta {
  background: var(--amber-400) !important;
  color: var(--slate-950) !important;
  margin-left: .5rem;
  font-weight: 600 !important;
}
.nav-cta:hover { background: var(--amber-300) !important; color: var(--slate-950) !important; }

/* Hamburger */
#nav-toggle {
  display: none;
  background: none; border: none; cursor: pointer;
  color: var(--white); font-size: 1.4rem; padding: .4rem;
}
@media (max-width: 820px) {
  #nav-toggle { display: block; }
  #main-nav {
    display: none; flex-direction: column;
    position: absolute; top: 64px; left: 0; right: 0;
    background: var(--slate-950);
    border-bottom: 2px solid var(--amber-400);
    padding: 1rem 1.5rem;
    gap: .3rem;
  }
  #main-nav.open { display: flex; }
  #main-nav a { width: 100%; }
}

/* --- BREADCRUMB --- */
.breadcrumb {
  background: var(--slate-100);
  border-bottom: 1px solid var(--slate-200);
  padding: .6rem 0;
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--slate-400);
}
.breadcrumb a { color: var(--teal-500); }
.breadcrumb a:hover { color: var(--amber-400); }
.breadcrumb span { margin: 0 .4rem; }

/* --- HERO --- */
.hero {
  background: var(--slate-950);
  color: var(--white);
  padding: 4rem 0 3.5rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 70% 60% at 80% 50%, rgba(20,184,166,.12), transparent),
              radial-gradient(ellipse 50% 40% at 20% 80%, rgba(245,158,11,.08), transparent);
}
.hero-inner {
  position: relative; z-index: 1;
  max-width: var(--max-width);
  margin: 0 auto; padding: 0 1.5rem;
}
.hero-label {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--teal-400);
  margin-bottom: .8rem;
}
.hero h1 {
  color: var(--white);
  margin-bottom: 1.2rem;
  max-width: 680px;
}
.hero h1 em { color: var(--amber-400); font-style: normal; }
.hero-desc {
  font-size: 1.1rem;
  color: var(--slate-200);
  max-width: 560px;
  margin-bottom: 2rem;
  line-height: 1.65;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* --- BUTTONS --- */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .75rem 1.5rem;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .88rem;
  font-weight: 600;
  text-decoration: none;
  transition: all .2s;
  cursor: pointer;
  border: none;
}
.btn-primary {
  background: var(--amber-400);
  color: var(--slate-950);
  box-shadow: var(--shadow-amber);
}
.btn-primary:hover { background: var(--amber-300); transform: translateY(-1px); color: var(--slate-950); }
.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 1.5px solid var(--slate-600);
}
.btn-secondary:hover { border-color: var(--teal-400); color: var(--teal-400); }
.btn-teal {
  background: var(--teal-500);
  color: var(--white);
  box-shadow: var(--shadow-teal);
}
.btn-teal:hover { background: var(--teal-400); transform: translateY(-1px); color: var(--white); }
.btn-sm { padding: .5rem 1rem; font-size: .8rem; }
.btn-lg { padding: .9rem 2rem; font-size: .95rem; }

/* --- CARDS --- */
.card {
  background: var(--white);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s, transform .2s;
}
.card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}
.card-label {
  font-family: var(--font-mono);
  font-size: .72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--teal-500);
  margin-bottom: .5rem;
}
.card h3 { margin-top: 0; font-size: 1.1rem; }
.card p { font-size: .93rem; color: var(--slate-600); }
.card-link {
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 600;
  color: var(--amber-400);
  text-decoration: none;
  display: inline-flex; align-items: center; gap: .3rem;
  margin-top: .8rem;
}
.card-link:hover { color: var(--teal-500); }

/* --- ARTICLE LAYOUT --- */
.article-header {
  background: var(--slate-950);
  color: var(--white);
  padding: 3rem 0 2.5rem;
  position: relative;
  overflow: hidden;
}
.article-header::after {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--teal-500), var(--amber-400), var(--teal-500));
}
.article-meta {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  margin-bottom: 1rem;
  font-family: var(--font-mono); font-size: .78rem;
  color: var(--slate-400);
}
.article-tag {
  background: var(--teal-500);
  color: var(--white);
  padding: .2rem .6rem;
  border-radius: 100px;
  font-size: .7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
}
.article-header h1 {
  color: var(--white);
  margin-bottom: 1rem;
  max-width: 760px;
}
.article-header .lead {
  font-size: 1.1rem;
  color: var(--slate-200);
  max-width: 680px;
  line-height: 1.65;
}

/* ARTICLE BODY */
.article-body {
  padding: 3rem 0;
}
.article-body p { font-size: 1rem; line-height: 1.8; }
.article-body h2 {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--slate-200);
}
.article-body h2:first-child { margin-top: 0; padding-top: 0; border-top: none; }

/* TOC */
.toc {
  background: var(--slate-100);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 2rem 0;
}
.toc-title {
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--slate-400);
  margin-bottom: 1rem;
}
.toc ol { padding-left: 1.2rem; }
.toc li { margin-bottom: .4rem; }
.toc a { color: var(--teal-500); font-size: .93rem; }

/* CALLOUT BOXES */
.callout {
  padding: 1.2rem 1.5rem;
  border-radius: var(--radius);
  margin: 1.8rem 0;
  border-left: 4px solid;
}
.callout-tip   { background: var(--teal-100);  border-color: var(--teal-500); }
.callout-warn  { background: var(--amber-100); border-color: var(--amber-400); }
.callout-info  { background: var(--bubble);    border-color: #0ea5e9; }
.callout-title {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: .4rem;
  color: var(--slate-700);
}

/* FAQ */
.faq { margin: 2.5rem 0; }
.faq-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  margin-bottom: 1.5rem;
  color: var(--slate-950);
}
details {
  border: 1px solid var(--slate-200);
  border-radius: var(--radius);
  margin-bottom: .75rem;
  background: var(--white);
  overflow: hidden;
}
details summary {
  padding: 1rem 1.2rem;
  cursor: pointer;
  font-weight: 600;
  font-size: .97rem;
  color: var(--slate-900);
  list-style: none;
  display: flex; justify-content: space-between; align-items: center;
  user-select: none;
}
details summary::-webkit-details-marker { display: none; }
details summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--teal-500);
  transition: transform .2s;
}
details[open] summary::after { transform: rotate(45deg); }
details[open] summary { border-bottom: 1px solid var(--slate-200); }
details > div {
  padding: 1rem 1.2rem;
  font-size: .95rem;
  color: var(--slate-700);
  line-height: 1.75;
}

/* DATA TABLES */
.data-table-wrap { overflow-x: auto; margin: 1.5rem 0; }
table {
  width: 100%; border-collapse: collapse;
  font-size: .9rem;
}
thead tr { background: var(--slate-900); color: var(--white); }
thead th {
  padding: .8rem 1rem; text-align: left;
  font-family: var(--font-mono); font-size: .78rem;
  font-weight: 600; text-transform: uppercase; letter-spacing: .06em;
}
tbody tr { border-bottom: 1px solid var(--slate-200); }
tbody tr:hover { background: var(--slate-100); }
tbody td { padding: .75rem 1rem; color: var(--slate-800); }
.td-highlight { font-weight: 600; color: var(--teal-500); }

/* --- TOOL / CALCULATOR --- */
.tool-section {
  background: var(--slate-900);
  color: var(--white);
  border-radius: var(--radius-xl);
  padding: 2.5rem;
  margin: 2.5rem 0;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}
.tool-section::before {
  content: '';
  position: absolute; top: -40%; right: -10%;
  width: 400px; height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(45,212,191,.08), transparent 70%);
  pointer-events: none;
}
.tool-header {
  display: flex; align-items: flex-start; gap: 1rem;
  margin-bottom: 2rem;
}
.tool-icon {
  width: 48px; height: 48px;
  background: linear-gradient(135deg, var(--teal-500), var(--teal-400));
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; flex-shrink: 0;
}
.tool-title { font-family: var(--font-display); font-size: 1.5rem; color: var(--white); }
.tool-desc  { font-size: .9rem; color: var(--slate-400); margin-top: .25rem; }
.tool-grid  { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }
@media (max-width: 640px) { .tool-grid { grid-template-columns: 1fr; } }
.form-group { display: flex; flex-direction: column; gap: .5rem; }
.form-label {
  font-family: var(--font-mono);
  font-size: .78rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: .08em;
  color: var(--slate-400);
}
.form-control {
  background: var(--slate-800);
  border: 1.5px solid var(--slate-700);
  color: var(--white);
  padding: .65rem .9rem;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: .9rem;
  width: 100%;
  transition: border-color .2s;
}
.form-control:focus { outline: none; border-color: var(--teal-500); }
.form-control option { background: var(--slate-800); }
.tool-result {
  background: var(--slate-950);
  border: 1.5px solid var(--teal-500);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  margin-top: 1.5rem;
  display: none;
}
.tool-result.visible { display: block; }
.result-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 1.2rem; }
.result-item {}
.result-label {
  font-family: var(--font-mono); font-size: .72rem;
  font-weight: 600; text-transform: uppercase; letter-spacing: .1em;
  color: var(--slate-400); margin-bottom: .3rem;
}
.result-value {
  font-family: var(--font-display); font-size: 1.9rem;
  color: var(--teal-400); line-height: 1;
}
.result-unit {
  font-family: var(--font-mono); font-size: .8rem;
  color: var(--slate-400); margin-top: .2rem;
}
.result-note {
  font-size: .88rem; color: var(--slate-300);
  margin-top: 1rem; line-height: 1.6;
  border-top: 1px solid var(--slate-800); padding-top: 1rem;
}

/* --- SIDEBAR LAYOUT --- */
.two-col {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 2.5rem;
  align-items: start;
}
@media (max-width: 900px) { .two-col { grid-template-columns: 1fr; } }
.sidebar { position: sticky; top: 84px; }
.sidebar-card {
  background: var(--white);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
}
.sidebar-title {
  font-family: var(--font-mono); font-size: .78rem;
  font-weight: 600; text-transform: uppercase; letter-spacing: .1em;
  color: var(--slate-400); margin-bottom: 1rem;
  padding-bottom: .75rem; border-bottom: 1px solid var(--slate-200);
}
.sidebar-links { list-style: none; padding: 0; }
.sidebar-links li { margin-bottom: .5rem; }
.sidebar-links a { font-size: .9rem; color: var(--teal-500); }
.sidebar-links a:hover { color: var(--amber-400); }

/* PSI BADGE */
.psi-badge {
  display: inline-flex; align-items: baseline; gap: .2rem;
  background: var(--slate-900); color: var(--teal-400);
  font-family: var(--font-mono); padding: .2rem .6rem;
  border-radius: var(--radius-sm); font-size: .88rem; font-weight: 600;
}

/* STEP LIST */
.step-list { list-style: none; padding: 0; counter-reset: steps; }
.step-list li {
  counter-increment: steps;
  display: flex; gap: 1rem; margin-bottom: 1.5rem;
  align-items: flex-start;
}
.step-list li::before {
  content: counter(steps);
  min-width: 32px; height: 32px;
  background: var(--slate-900); color: var(--amber-400);
  font-family: var(--font-mono); font-weight: 600; font-size: .85rem;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}

/* STAT STRIP */
.stat-strip {
  background: var(--slate-900);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  display: flex; gap: 2rem; flex-wrap: wrap;
  margin: 2rem 0;
}
.stat-item { text-align: center; }
.stat-num {
  font-family: var(--font-display); font-size: 2rem;
  color: var(--teal-400); line-height: 1;
  display: block;
}
.stat-label {
  font-family: var(--font-mono); font-size: .72rem;
  text-transform: uppercase; letter-spacing: .08em;
  color: var(--slate-400); margin-top: .25rem;
  display: block;
}

/* --- SECTION WRAPPERS --- */
.section { padding: 3.5rem 0; }
.section-alt { background: var(--slate-100); }
.section-dark { background: var(--slate-950); color: var(--white); }
.section-label {
  font-family: var(--font-mono); font-size: .78rem;
  font-weight: 600; text-transform: uppercase; letter-spacing: .12em;
  color: var(--teal-500); margin-bottom: .6rem;
}
.section-title { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: .75rem; }
.section-desc { font-size: 1rem; color: var(--slate-600); max-width: 560px; margin-bottom: 2rem; }
.section-dark .section-title { color: var(--white); }
.section-dark .section-desc  { color: var(--slate-300); }
.section-dark .section-label { color: var(--teal-400); }

/* --- FOOTER --- */
#site-footer {
  background: var(--slate-950);
  color: var(--slate-400);
  padding: 3rem 0 1.5rem;
  border-top: 2px solid var(--amber-400);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  max-width: var(--max-width);
  margin: 0 auto; padding: 0 1.5rem;
  margin-bottom: 2.5rem;
}
@media (max-width: 760px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 480px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-brand .logo-text { color: var(--white); }
.footer-desc { font-size: .9rem; margin-top: .75rem; line-height: 1.65; }
.footer-col-title {
  font-family: var(--font-mono); font-size: .78rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: .1em; color: var(--slate-200);
  margin-bottom: .9rem;
}
.footer-col ul { list-style: none; padding: 0; }
.footer-col li { margin-bottom: .45rem; }
.footer-col a { color: var(--slate-400); font-size: .88rem; }
.footer-col a:hover { color: var(--amber-400); }
.footer-bottom {
  max-width: var(--max-width); margin: 0 auto;
  padding: 1.5rem 1.5rem 0;
  border-top: 1px solid var(--slate-800);
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: .75rem;
  font-family: var(--font-mono); font-size: .75rem;
}
.footer-bottom a { color: var(--slate-400); }
.footer-bottom a:hover { color: var(--teal-400); }

/* --- DISCLAIMER BOX --- */
.disclaimer {
  background: var(--slate-100); border: 1px solid var(--slate-200);
  border-radius: var(--radius); padding: 1rem 1.2rem;
  font-size: .82rem; color: var(--slate-600); margin: 2rem 0;
  font-family: var(--font-mono); line-height: 1.6;
}
.disclaimer strong { color: var(--slate-700); }

/* PDF CTA */
.pdf-cta {
  background: linear-gradient(135deg, var(--slate-900), var(--slate-800));
  border: 1.5px solid var(--amber-400);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  display: flex; align-items: center; gap: 1.5rem;
  margin: 2.5rem 0;
}
.pdf-icon { font-size: 2.2rem; flex-shrink: 0; }
.pdf-cta h4 { color: var(--white); margin: 0 0 .3rem; font-size: 1rem; }
.pdf-cta p  { color: var(--slate-300); font-size: .88rem; margin: 0; }

/* RELATED ARTICLES */
.related { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--slate-200); }
.related-title {
  font-family: var(--font-mono); font-size: .78rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: .1em; color: var(--slate-400);
  margin-bottom: 1rem;
}
.related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 1rem; }
.related-card {
  border: 1px solid var(--slate-200); border-radius: var(--radius);
  padding: 1rem; background: var(--white);
  transition: border-color .2s;
}
.related-card:hover { border-color: var(--teal-400); }
.related-card .card-label { margin-bottom: .3rem; }
.related-card h4 { margin: 0; font-size: .95rem; }
.related-card a { color: var(--slate-900); font-size: .93rem; }
.related-card a:hover { color: var(--teal-500); }

/* ADSENSE PLACEHOLDER */
.ad-slot {
  background: var(--slate-100); border: 1px dashed var(--slate-300);
  border-radius: var(--radius); padding: 1.5rem;
  text-align: center; color: var(--slate-400);
  font-family: var(--font-mono); font-size: .75rem;
  margin: 2rem 0;
}

/* INLINE HIGHLIGHTS */
.highlight-box {
  background: linear-gradient(135deg, var(--teal-100), var(--bubble));
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: 1.8rem 0;
}
.highlight-box h3 { margin-top: 0; font-size: 1.05rem; }
.highlight-box p  { margin-bottom: 0; font-size: .93rem; }

/* --- ANIMATIONS --- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp .6s ease both; }
.fade-up-2 { animation: fadeUp .6s .15s ease both; }
.fade-up-3 { animation: fadeUp .6s .3s ease both; }

/* --- UTILITIES --- */
.text-center { text-align: center; }
.text-mono { font-family: var(--font-mono); }
.text-teal   { color: var(--teal-500); }
.text-amber  { color: var(--amber-400); }
.text-muted  { color: var(--slate-400); }
.mt-1 { margin-top: .5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: 1rem; }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: .5rem; }
.gap-2 { gap: 1rem; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.w-full { width: 100%; }

/* --- RESPONSIVE --- */
@media (max-width: 640px) {
  .hero { padding: 2.5rem 0 2rem; }
  .section { padding: 2.5rem 0; }
  .tool-section { padding: 1.5rem; }
  .pdf-cta { flex-direction: column; }
  .stat-strip { flex-direction: column; gap: 1rem; }
}