/* ===============================
   GLOBAL RESET
================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Nunito", sans-serif;
  background: #f6f7fb;
  color: #333;
  height: 100vh;
}

/* ===============================
   HEADER
================================ */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 30px;
  background: #ffffff;
  border-bottom: 1px solid #e6e6e6;
}

#heading h2 {
  font-family: "Jersey 10", cursive;
  font-size: 32px;
}

#heading h2 span {
  color: #7b3fe4;
}

#heading p {
  font-size: 13px;
  color: #777;
}

#navbar a {
  text-decoration: none;
  margin-left: 18px;
  font-weight: 600;
  color: #333;
}

#navbar a:hover {
  color: #7b3fe4;
}

/* ===============================
   MAIN CONTAINER
================================ */
.container {
  display: grid;
  grid-template-columns: 280px 1fr;
  height: calc(100vh - 70px);
  gap: 18px;
  padding: 18px;
}

/* ===============================
   SIDEBAR
================================ */
.sidebar {
  background: #ffffff;
  border-radius: 16px;
  padding: 14px;
  overflow-y: auto;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

/* Topic title */
.topic-title {
  font-weight: 700;
  padding: 12px 14px;
  margin-bottom: 6px;
  border-radius: 10px;
  cursor: pointer;
  background: #f2f2f8;
}

.topic-title:hover {
  background: #e8e4ff;
}

/* Subtopics */
.subtopic-list {
  list-style: none;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  margin-left: 8px;
}

.subtopic-list.open {
  max-height: 600px;
}

.subtopic-list li {
  padding: 8px 12px;
  margin: 6px 0;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
}

.subtopic-list li:hover {
  background: #f3eaff;
}

/* Active lesson */
.subtopic-list li.active {
  background: #7b3fe4;
  color: #ffffff;
  font-weight: 600;
}

/* ===============================
   CONTENT AREA (MATCHES IMAGE)
================================ */
.content {
  background: #f3eaff; /* soft purple */
  border-radius: 20px;
  padding: 30px;
  overflow-y: auto;
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.06);
}

/* Content typography */
.content h1 {
  font-size: 30px;
  margin-bottom: 14px;
}

.content h2 {
  margin-top: 22px;
  margin-bottom: 10px;
}

.content p {
  line-height: 1.7;
  margin-bottom: 12px;
  color: #444;
}

/* ===============================
   SCROLLBAR (OPTIONAL POLISH)
================================ */
.sidebar::-webkit-scrollbar,
.content::-webkit-scrollbar {
  width: 6px;
}

.sidebar::-webkit-scrollbar-thumb,
.content::-webkit-scrollbar-thumb {
  background: #c7bfff;
  border-radius: 10px;
}
/* ===============================
   CONTENT HEADER
================================ */
.content-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
}

/* Three dot button */
.menu-wrapper {
  position: relative;
}

.menu-btn {
  background: transparent;
  border: none;
  font-size: 22px;
  cursor: pointer;
  padding: 6px 10px;
  border-radius: 8px;
}

.menu-btn:hover {
  background: rgba(0, 0, 0, 0.08);
}

/* Dropdown menu */
.menu-dropdown {
  position: absolute;
  right: 0;
  top: 38px;
  background: #ffffff;
  border-radius: 10px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.12);
  min-width: 160px;
  display: none;
  overflow: hidden;
  z-index: 10;
}

.menu-dropdown div {
  padding: 10px 14px;
  cursor: pointer;
  font-size: 14px;
}

.menu-dropdown div:hover {
  background: #f3eaff;
}
/* ===============================
   SIDEBAR TOGGLE (DESKTOP)
================================ */

/* Toggle button */
.toggle-btn {
  font-size: 22px;
  background: transparent;
  border: none;
  cursor: pointer;
  margin-right: 12px;
}

/* Sidebar transition */
.sidebar {
  transition: transform 0.3s ease, opacity 0.3s ease;
}

/* Hidden sidebar */
.sidebar.hidden {
  transform: translateX(-120%);
  opacity: 0;
}

/* Expand content when sidebar hidden */
.container.full-width {
  grid-template-columns: 0 1fr;
}

/* Smooth content resize */
.content {
  transition: all 0.3s ease;
}
/* ===============================
   FIXED HEADER (GUARANTEED)
================================ */

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

  padding: 14px 28px;
  background: #ffffff;
  border-bottom: 1px solid #e6e6e6;
}

/* LEFT SIDE */
.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* TOGGLE BUTTON */
#sidebarToggle {
  font-size: 22px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 6px 8px;
  border-radius: 8px;
  line-height: 1;
  /* background-color: aliceblue; */
}

#sidebarToggle:hover {
  background: aliceblue;
}

/* BRAND */
.brand h2 {
  font-family: "Jersey 10", cursive;
  font-size: 32px;
  line-height: 1;
}

.brand h2 span {
  color: #7b3fe4;
}

.brand p {
  font-size: 13px;
  color: #777;
  margin-top: 2px;
}

/* NAV */
.header-nav a {
  text-decoration: none;
  margin-left: 18px;
  font-weight: 600;
  color: #333;
}

.header-nav a:hover {
  color: #7b3fe4;
}
/* TOGGLE BUTTON */
.menu-toggle {
  display: none;
  font-size: 28px;
  cursor: pointer;
  user-select: none;
  /* background-color: aliceblue; */
}

/* MOBILE VIEW */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  .header-nav {
    display: none;
    flex-direction: column;
    width: 100%;
    background-color: transparent;
    position: absolute;
    top: 60px;
    left: 0;
    border-top: 1px solid #ddd;
  }

  .header-nav a {
    padding: 14px;
    text-align: center;
    border-bottom: 1px solid #eee;
  }

  .header-nav.active {
    display: flex;
  }
}
/* ===============================
   FOOTER
================================ */
.site-footer {
  background: #ffffff;
  border-top: 1px solid #e6e6e6;
  margin-top: 30px;
}

.footer-container {
  max-width: 1200px;
  margin: auto;
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

/* Brand */
.footer-brand h3 {
  font-family: "Jersey 10", cursive;
  font-size: 28px;
  margin-bottom: 4px;
}

.footer-brand h3 span {
  color: #7b3fe4;
}

.footer-brand p {
  font-size: 13px;
  color: #777;
}

/* Links */
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
}

.footer-links a {
  text-decoration: none;
  font-size: 14px;
  color: #444;
  font-weight: 600;
}

.footer-links a:hover {
  color: #7b3fe4;
}

/* Copyright */
.footer-copy {
  font-size: 13px;
  color: #777;
}