/* ======================================================
   DESIGN SYSTEM / TOKENS
====================================================== */
:root {
  --bg-root: #282828;
  --bg-surface: #373737;
  --bg-surface-muted: rgba(25,25,25,0.6);
  --bg-glass: rgba(55,55,55,0.65);

  --accent-primary: #E0BEF9;
  --accent-contrast: #390C5B;
  --accent-warm: #FFE500;

  --text-primary: #ffffff;
  --text-secondary: rgba(255,255,255,0.78);
  --text-muted: rgba(255,255,255,0.55);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-pill: 999px;

  --shadow-soft: 0 8px 28px rgba(0,0,0,0.28);
  --shadow-medium: 0 18px 60px rgba(0,0,0,0.4);

  --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-emphasized: cubic-bezier(0.2, 0, 0, 1);

  --motion-fast: 150ms;
  --motion-medium: 300ms;
  --motion-slow: 700ms;

  --section-gap: 96px;
}
/* ======================================================
   GLOBAL
====================================================== */
* {
  box-sizing: border-box;
}

body {
  font-family: "Funnel Sans", sans-serif;
  background: var(--bg-root);
  color: var(--text-primary);
  font-weight: 300;
  font-size: 16px;
  margin: 0;
  overflow-x: hidden;
  perspective: 1400px;
}

section {
  margin-bottom: var(--section-gap);
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
}

/* ======================================================
   BACKGROUND DECORATION
====================================================== */
.site-background {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.bg-vector-wrapper {
  position: absolute;
  top: -140px;
  right: -260px;
  width: 900px;
  opacity: 0.22;
  animation: float 14s ease-in-out infinite;
}

@keyframes float {
  0% { transform: translateY(0); }
  50% { transform: translateY(-28px); }
  100% { transform: translateY(0); }
}

/* ======================================================
   NAVBAR
====================================================== */

.custom-navbar {
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  padding: 14px 0;
  transition: all var(--motion-medium) var(--ease-standard);
  display: flex;          
  align-items: center;    
  gap: 10px;              
}

.navbar-brand {
  font-weight: 700;
}

.custom-navbar .nav-link {
  color: var(--text-primary);
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-right: 10px;
  position: relative;
  transition: color var(--motion-fast) var(--ease-standard);
}

.custom-navbar .nav-link:hover,
.custom-navbar .nav-link.active {
  color: var(--accent-primary);
}

.custom-navbar .nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 50%;
  width: 18px;
  height: 2px;
  background: var(--accent-primary);
  transform: translateX(-50%);
  border-radius: 2px;
}

.nav-cta {
  height: 40px;                   
  padding: 0 28px;                
  display: flex;                
  align-items: center;   
  justify-content: center;
  border-radius: var(--radius-pill);
  background: linear-gradient(135deg, var(--accent-primary), #c8a4f1);
  color: var(--accent-contrast);
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
  transition: transform var(--motion-fast) var(--ease-emphasized),
              box-shadow var(--motion-fast) var(--ease-emphasized);
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
}

.navbar-toggler-icon {
  filter: invert(100%);
}

/* Mobile / tablet only */
@media (max-width: 991px) {
  /* Only target the expanded menu */
  .navbar-collapse.collapse.show {
    display: flex !important;
    flex-direction: column;
    align-items: center;
    text-align: center;
    width: 100%;
  }

  /* Remove left auto margin from links */
  .navbar-nav.ms-auto {
    margin-left: 0 !important;
  }

  .navbar-collapse .nav-link,
  .navbar-collapse .nav-cta {
    margin: 8px 0; /* spacing */
  }
}

/* ======================================================
   HERO / CHAT
====================================================== */

.chat-wrapper {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

/* Profile image */
.chat-avatar {
  width: 54px;
  transition: transform 0.3s ease;
}

.chat-avatar img {
  width: 54px;
  height: 54px;
  border-radius: 50%;
  object-fit: cover;
}

/* Messages column */
.chat-messages {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Chat bubble */
.chat-bubble {
  background-color: #414141;
  color: white;
  padding: 10px 14px;
  border-radius: 4px;
  width: fit-content;
  max-width: 480px;
  font-size: 16px;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

/* Visible state */
.chat-bubble.show {
  opacity: 1;
  transform: translateY(0);
}

.hidden {
  display: block; /* or inline-block */
}

/* --------------------
   FITNESS APP SECTION
-------------------- */
.fitness-app-section {
  position: relative;
  background: #373737;
  border-radius: 24px;
  overflow: visible;

  /* Responsive width/margins like Earlier Work Section */
  margin-left: 80px;
  margin-right: 80px;
  padding-left: 32px;
  padding-right: 32px;
}

/* Gradient background shape */


.fitness-app-section {
  position: relative;
  background-color: #373737; /* solid background */
  background-image: url("images/bg-fitness.svg"); /* SVG on top */
  background-repeat: no-repeat;
  background-position: left top;
  background-size: 700px auto;
  border-radius: 24px;
  overflow: hidden;
}

/* Section header */
.fitness-title {
  color: white;
  font-family: "Funnel Sans", sans-serif;
  font-size: 24px;
  font-weight: 600;
}

.selected-work {
  background: #DED4E8;
  border-radius: 24px;
  padding: 4px 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.selected-work span {
  color: #390C5B;
  font-family: "Funnel Sans", sans-serif;
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
}

/* Main image — desktop scaling only */
.main-image {
  width: clamp(320px, 36vw, 480px);
  filter: drop-shadow(0 24px 60px rgba(0,0,0,0.45));
}

/* Main description */
.fitness-description p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Chapters */
.chapter-card {
  background: var(--bg-surface-muted);
  border-radius: var(--radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  text-decoration: none;
  transition: transform var(--motion-medium) var(--ease-emphasized),
              box-shadow var(--motion-medium) var(--ease-emphasized);
}

a.chapter-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}

/* Hover affordance / overlay */
.chapter-card::after {
  content: "Read Chapter →";
  position: absolute;
  inset: 0; /* cover entire card */
  background: linear-gradient(rgba(0,0,0,0.6), rgba(0,0,0,0.95));
  display: flex;
  align-items: flex-end;     /* align content to bottom */
  justify-content: flex-end; /* align content to right */
  font-size: 16px;
  font-weight: 600;
  color: #E0BEF9;
  opacity: 0;
  transform: translateY(6px); /* subtle slide-up effect */
  transition: opacity var(--motion-medium) var(--ease-standard),
              transform var(--motion-medium) var(--ease-standard);
  pointer-events: none; /* allow clicks through overlay */
  text-align: right;
  padding: 16px 24px; /* space from bottom & right edges */
  border-radius: inherit; /* match card rounding */
}

/* Show overlay on hover */
.chapter-card:hover::after {
  opacity: 1;
  transform: translateY(0); /* slide to final position */
}

/* Show overlay on hover */
.chapter-card:hover::after {
  opacity: 1;
  transform: scale(1);
}

.chapter-card .chapter-subtitle {
  font-family: "Funnel Sans", sans-serif;
  font-size: 16px;
  color: white;
}

.chapter-card .chapter-label {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.chapter-card .chapter-title {
  font-family: "Funnel Sans", sans-serif;
  font-size: 18px;
  color: #ede0f6;
  font-weight: 700;
}

.chapter-card .chapter-link {
  font-family: "Funnel Sans", sans-serif;
  font-size: 16px;
  color: white;
  text-align: right;
}

/* Main content fade-in */
#main-content {
  display: none;
  opacity: 0;
  transition: opacity 1.6s ease-in-out;
}
#main-content.show {
  display: block;
  opacity: 1;
}

/* --------------------
   RESPONSIVE / MOBILE
-------------------- */
@media (max-width: 767px) {

  /* Reduce section padding */
  .fitness-app-section {
    padding: 20px 15px; /* horizontal padding matches Earlier Work Section */
    margin-left: 20px;
    margin-right: 20px;
  }

  /* Stack main content vertically */
  .fitness-app-section .d-flex.align-items-center {
    flex-direction: column;
    gap: 24px;
  }

  /* Stack chapters vertically */
  .fitness-app-section .d-flex.mt-4 {
    flex-direction: column;
    gap: 16px;
  }

  /* Smaller title and description */
  .fitness-title {
    font-size: 20px;
  }

  .fitness-description p {
    font-size: 14px;
  }

  /* Smaller "Selected Work" box */
  .selected-work {
    padding: 6px 12px;
  }
}

.site-background {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
  perspective: 1000px;
}

/* Wrapper = floating */
.bg-vector-wrapper {
  position: absolute;
  top: -100px;
  right: -200px;
  width: 900px;
  opacity: 0.25;
  transform-style: preserve-3d;
  animation: float 12s ease-in-out infinite;
}


/* Inner = rotation */
.bg-vector {
  width: 100%;
  transform-style: preserve-3d;
  transform-origin: center;
  will-change: transform;
}

/* Float animation (translate ONLY) */
@keyframes float {
  0% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
  100% {
    transform: translateY(0);
  }
}

/* Perspective */
body {
  perspective: 1000px;
}

nav,
section {
  position: relative;
  z-index: 1;
}   

/* --------------------
   EARLIER WORK SECTION
-------------------- */
.earlier-work-section {
  position: relative;
  padding-left: 0px;
  padding-right: 0px;
  padding-top: 60px;
  margin-left: 40px;
  margin-right: 40px;
}

.earlier-work-section .section-title {
  color: white;
  font-family: "Funnel Sans", sans-serif;
  font-size: 24px;
  font-weight: 700;
}

.custom-container-2 {
  max-width: 1440px;
  margin: 0 0px;
  padding: 0 40px;
}

@media (max-width: 768px) {
  .custom-container-2 {
    padding: 0px; /* reduced padding on smaller screens */
  }
}

/* Work cards container — GRID */
.work-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  width: 100%;
}

/* Base card styles */
.work-card {
  min-width: 0; /* allow grid items to shrink */
  border-radius: 24px;
  padding: 20px;
  display: flex;
  background: var(--bg-surface);
  border-radius: var(--radius-lg);
  flex-direction: column;
  gap: 16px;
  overflow: hidden;
  position: relative;
  color: white;
  text-decoration: none;
  transition: transform var(--motion-medium) var(--ease-emphasized),
              box-shadow var(--motion-medium) var(--ease-emphasized);
}

a.work-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}

/* Hover affordance / overlay */
.work-card::after {
  content: "View project ↗";
  position: absolute;
  inset: 0; /* cover entire card */
  background: linear-gradient(rgba(0,0,0,0.6), rgba(0, 0, 0, 0.951));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 600;
  color: #E0BEF9; 
  opacity: 0;
  transform: scale(0.95); /* subtle zoom-in effect */
  transition: opacity var(--motion-medium) var(--ease-standard),
              transform var(--motion-medium) var(--ease-standard);
  pointer-events: none; /* allow clicks through overlay */
  text-align: center;
  padding: 0 12px; /* prevent text from touching edges */
  border-radius: inherit; /* match card rounding */
}

/* Show overlay on hover */
.work-card:hover::after {
  opacity: 1;
  transform: scale(1);
}

/* Header inside card */
.work-header {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

/* Title inside card */
.work-title {
  font-family: "Funnel Sans", sans-serif;
  font-size: 20px;
  font-weight: 300;
  color: white;
  text-align: center;
}

.work-title .work-main {
  font-weight: 600;
}

/* Image inside card */
.work-image {
  width: 100%;
  height: auto;
  display: block;
}

/* Mobile responsiveness */
@media (max-width: 767px) {
  .earlier-work-section {
    padding: 40px 0px;
    margin-left: 16px;
    margin-right: 16px;
  }

  .section-title {
    font-size: 20px;
  }

  .work-cards {
    /* Make cards stack vertically */
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .work-card {
    max-width: 100%; /* keeps cards from shrinking horizontally */
  }

  .work-title {
    font-size: 20px;
  }
}


/* --------------------
   CHAPTER PAGE
-------------------- */

.chapter-breadcrumb {
  padding: 24px 0;
  color: rgba(255,255,255,0.6);
  font-size: 14px;
}

.breadcrumb-separator {
  margin: 0 8px;
}

.breadcrumb-current {
  color: white;
  font-weight: 600;
}

.breadcrumb-link {
  color: rgba(255,255,255,0.6);
  text-decoration: none;
}

.breadcrumb-link:hover {
  color: white;
  text-decoration: underline;
}

.chapter-section {
  padding: 0px;
  margin-bottom: 0px;
}

.chapter-container {
  max-width: 880px; /* adjust based on your taste */
  margin: 0 auto;
  padding: 0 0px;
}

.chapter-header,
.chapter-content {
  text-align: left;
}


.chapter-title {
  color: white;
  font-size: 32px;
  font-weight: 700;
}

.chapter-subtitle {
  color: rgba(255,255,255,0.7);
  font-size: 18px;
}

.chapter-content {
  padding: 40px 0;
  margin: 0px;
}

/* Tablet (e.g., max-width: 1024px) */
@media (max-width: 1024px) {
  .chapter-content {
    padding-left: 24px;
    padding-right: 24px;
  }
}

/* Mobile (e.g., max-width: 767px) */
@media (max-width: 767px) {
  .chapter-content {
    padding-left: 16px;
    padding-right: 16px;
  }
}

/* Tablet (e.g., max-width: 1024px) */
@media (max-width: 1024px) {
  .chapter-container {
    padding-left: 24px;
    padding-right: 24px;
  }
}

/* Mobile (e.g., max-width: 767px) */
@media (max-width: 767px) {
  .chapter-container {
    padding-left: 16px;
    padding-right: 16px;
  }
}

.content-block {
  max-width: 880px;
  margin: 0 auto 48px;
}

.content-block h3 {
  color: #E0BEF9;
  font-size: 20px;
  margin-bottom: 16px;
}

.content-block h2 {
  color: #BDC0ED;
  font-size: 18px;
  margin-bottom: 16px;
}

.content-block p {
  color: white;
  line-height: 1.6;
}

.insight-list {
  list-style: none;
  padding: 0;
  margin: 24px 0;
}

.insight-list li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 16px;
  color: white;
  line-height: 1.6;
}

.insight-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 8px;
  height: 8px;
  background-color: #E0BEF9;
  border-radius: 50%;
}

.image-block {
  margin: 60px auto;
  text-align: center;
  max-width: 640px;
}

.image-block img {
  max-width: 100%;
  border-radius: 16px;
}

.image-caption {
  color: rgba(255,255,255,0.6);
  font-size: 14px;
  margin-top: 12px;
}

/* Insight table */
.insight-table {
  border-radius: 16px;
  overflow: hidden;
  background: rgba(25,25,25,0.6);
  margin-top: 32px;
}

.table-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 14px 20px;
  color: white;
}

.table-header {
  font-weight: 700;
  background: #1B1B1B;
}

.chapter-hero {
  margin: 40px 0 64px;
}

.chapter-hero img {
  width: 100%;
  height: auto;
  border-radius: 24px;
  display: block;
}

.chapter-hero {
  background: #1f1f1f;
  padding: 24px;
  border-radius: 28px;
}


/* Next chapter */
.chapter-navigation {
  padding: 80px 0;
  border-top: 1px solid rgba(255,255,255,0.1);
  max-width: 880px;
  margin: 0 auto;
}

.chapter-nav-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  max-width: 900px;
}

.next-chapter-link {
  display: flex;
  align-items: center;
  gap: 24px;
  text-decoration: none;
  color: white;
  max-width: 720px;
}

.next-icon {
  font-size: 28px;
  color: #E0BEF9;
  flex-shrink: 0;
}

.next-text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.next-label {
  font-size: 14px;
  color: rgba(255,255,255,0.6);
}

.next-title {
  font-size: 20px;
  font-weight: 700;
}

.next-subtitle {
  font-size: 16px;
  color: rgba(255,255,255,0.75);
}

.next-chapter-link:hover .next-icon {
  transform: translateX(4px);
  transition: transform 0.2s ease;
}

.custom-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 40px;
}

@media (max-width: 768px) {
  .custom-container {
    padding: 0 16px; /* reduced padding on smaller screens */
  }
}

.chapter-navigation .custom-container {
  display: flex;
  width: 100%
}

.chapter-navigation.only-next .custom-container {
  justify-content: flex-end;
}

.chapter-navigation.both .custom-container {
  justify-content: space-between;
  max-width: 1100px;
}

.chapter-navigation.only-prev .custom-container {
  justify-content: flex-start;
}

/* ======================================================
   FOOTER — PRODUCT DESIGNER SIGNATURE
====================================================== */

.portfolio-footer {
  padding: 120px 40px 100px;
  background:
    radial-gradient(
      800px 400px at 20% -20%,
      rgba(118, 118, 118, 0.15),
      transparent 60%
    ),
    #1d1d1d;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 64px;
  align-items: center;
}

/* Intro */
.footer-eyebrow {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.footer-name {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 12px;
}

.footer-description {
  max-width: 420px;
  font-size: 17px;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

/* CTA */
.footer-cta {
  display: inline-block;
  padding: 14px 36px;
  border-radius: var(--radius-pill);
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    #c7a1ef
  );
  color: var(--accent-contrast);
  font-weight: 800;
  text-decoration: none;
  box-shadow: var(--shadow-soft);
  transition: transform var(--motion-fast) var(--ease-emphasized),
              box-shadow var(--motion-fast) var(--ease-emphasized);
}

.footer-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-medium);
}

/* Social icons */
.footer-socials {
  display: flex;
  gap: 24px;
}

.footer-socials a {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255,255,255,0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--motion-fast) var(--ease-standard),
              transform var(--motion-fast) var(--ease-emphasized);
}

.footer-socials a:hover {
  background: rgba(224,190,249,0.18);
  transform: translateY(-3px);
}

.footer-socials svg {
  width: 20px;
  height: 20px;
  fill: var(--text-primary);
}

/* Mobile */
@media (max-width: 768px) {
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 48px;
    text-align: center;
  }

  .footer-description {
    margin-left: auto;
    margin-right: auto;
  }

  .footer-socials {
    justify-content: center;
  }
}

.thinking-note {
  background:
    radial-gradient(
      800px 400px at 20% -20%,
      rgba(118, 118, 118, 0.1),
      transparent 40%
    ),
    #1d1d1d;
  border-radius: 24px;
  padding: 24px 28px;
}

.thinking-note p {
  margin: 0;
  color: rgba(255, 255, 255, 0.85);
  font-size: 16px;
  line-height: 1.5;
}

/* Main construction section */
.construction {
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.construction-inner {
  max-width: 480px;
  padding: 40px 20px;
}

/* Heading + text */
.construction h2 {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: #E0BEF9;
}

.construction p {
  font-size: 1rem;
  color: #c7c7c7;
  line-height: 1.6;
}

/* Building animation */
.building-animation {
  display: flex;
  justify-content: center;
  gap: 6px;
  margin-bottom: 24px;
  height: 40px;
}

.building-animation span {
  width: 10px;
  background-color: #453846;
  border-radius: 2px;
  animation: build 1.2s ease-in-out infinite;
}

/* Stagger animation */
.building-animation span:nth-child(1) { animation-delay: 0s; }
.building-animation span:nth-child(2) { animation-delay: 0.15s; }
.building-animation span:nth-child(3) { animation-delay: 0.3s; }
.building-animation span:nth-child(4) { animation-delay: 0.45s; }

@keyframes build {
  0% {
    height: 8px;
    opacity: 0.4;
  }
  50% {
    height: 40px;
    opacity: 1;
  }
  100% {
    height: 8px;
    opacity: 0.4;
  }
}

.tabs-section {
  background: rgba(25,25,25,0.6);
  padding: 24px;             /* inner spacing */
  border-radius: 12px;       /* optional rounded corners */
  box-shadow: var(--shadow-soft); /* subtle shadow if you like */
  margin-bottom: 32px;       /* spacing from other sections */
  margin-top: 32px;
}

.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  
  position: sticky; /* makes it stick */
  top: 100px; 
  z-index: 100;     /* ensures it stays above content */
  background-color: #3D3A40; /* same as tab container or dark bg */
  padding: 8px 8px;  /* optional: padding inside sticky bar */
  border-radius: var(--radius-pill); /* optional rounding */
}


/* Tabs buttons */
.tab {
  flex: 1;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-pill);
  background: #3D3A40; /* new background color */
  color: #ffffff;       /* text color white */
  font-weight: 700;
  font-size: 15px;
  cursor: pointer;
  box-shadow: none;     /* remove shadow/border effect */
  border: none;         /* ensure no border */
  transition: transform 0.2s, background 0.3s;
}

/* Hover effect (optional, slightly lighter) */
.tab:hover {
  background: #504b52;
}

.tab.active {
  background: linear-gradient(135deg, var(--accent-primary), #c8a4f1);
  color: var(--accent-contrast);
}

/* Tab content */
.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  margin-top: 16px;
}

.chapter-layout {
  display: flex;
  gap: 40px; /* space between content and sidebar */
  align-items: flex-start;
}

.chapter-content {
  flex: 1; /* take remaining space */
}

.chapter-sidebar {
  width: 250px; /* fixed width for sidebar */
  position: sticky;
  top: 100px; /* sticks while scrolling */
  align-self: flex-start;
}

.chapter-sidebar .chapter-nav ul {
  list-style: none;
  padding: 0;
}

.chapter-sidebar .chapter-nav li {
  margin-bottom: 12px;
}

.chapter-sidebar .chapter-nav a {
  color: #333;
  text-decoration: none;
}

.chapter-sidebar .chapter-nav a:hover {
  text-decoration: underline;
}

/* Responsive: move sidebar below content on smaller screens */
@media (max-width: 991px) {
  .chapter-layout {
    flex-direction: column;
  }

  .chapter-sidebar {
    width: 100%;
    position: static;
    margin-top: 20px;
  }
}