@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;600;700&display=swap');
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Montserrat', Arial, sans-serif;
  background-color: #f4f8fb;
  color: #228B22;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}
.main-header {
  background-color: #228B22;
  color: #fff;
  padding: 10px 25px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
  height: 70px;
  flex-shrink: 0;
  border-bottom: 1px solid #32CD32;
}
.logo-container { display: flex; align-items: center; }
.logo {
  font-size: 1.3em;
  font-weight: bold;
  background-color: #32CD32;
  color: #fff;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-right: 15px;
}
.header-title { display: flex; flex-direction: column; justify-content: center; text-align: left; }
.header-title .module-name { font-size: 0.9em; color: #b2f2b2; }
.header-title .content-title { font-size: 1.1em; font-weight: 500; }
.main-nav { display: flex; align-items: center; gap: 10px; }
.main-nav .nav-link {
  color: #fff;
  text-decoration: none;
  margin-left: 15px;
  padding: 8px 15px;
  border-radius: 6px;
  transition: background-color 0.3s, color 0.3s;
  font-size: 0.95em;
}
.main-nav .nav-link:hover,
.main-nav .nav-link.active-nav {
  background-color: #32CD32;
  color: #fff;
}
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5em;
  cursor: pointer;
  padding: 5px;
  border-radius: 4px;
  transition: background-color 0.3s;
  margin-left: 5px;
}
.mobile-menu-toggle:hover { background-color: rgba(255,255,255,0.1); }
.mobile-buttons { display: none; gap: 5px; }
.main-layout {
  display: flex;
  flex-grow: 1;
  overflow: hidden;
  height: calc(100vh - 70px);
}
.sidebar.left, .sidebar.right, .content-area {
  padding: 20px 25px;
  overflow-y: auto;
  height: 100%;
}
.sidebar.left, .sidebar.right {
  background-color: #32CD32;
  width: 24%;
  min-width: 280px;
  color: #fff;
}
.sidebar.left { order: 1; border-right: 1px solid #228B22; }
.sidebar.right { order: 3; border-left: 1px solid #228B22; }
.content-area {
  background-color: #fff;
  flex-grow: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  order: 2;
  padding: 15px;
  color: #228B22;
}
iframe#content-frame {
  width: 100%;
  height: 100%;
  border: none;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(34,205,50,0.08);
}
.sidebar.left::-webkit-scrollbar,
.sidebar.right::-webkit-scrollbar,
.content-area::-webkit-scrollbar { width: 8px; }
.sidebar.left::-webkit-scrollbar-thumb,
.sidebar.right::-webkit-scrollbar-thumb,
.content-area::-webkit-scrollbar-thumb { background-color: #228B22; border-radius: 4px; }
.sidebar.left::-webkit-scrollbar-track,
.sidebar.right::-webkit-scrollbar-track,
.content-area::-webkit-scrollbar-track { background-color: #32CD32; }
.sidebar h2 {
  color: #fff;
  font-size: 0.9em;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 0;
  margin-bottom: 15px;
  padding-bottom: 10px;
  border-bottom: 1px solid #228B22;
}
.sidebar ul { list-style: none; padding: 0; margin-top: 0; }
.sidebar ul li + li { margin-top: 6px; }
.sidebar a {
  display: flex;
  align-items: center;
  color: #eaffea;
  text-decoration: none;
  padding: 12px 10px;
  border-radius: 6px;
  transition: background-color 0.2s, color 0.2s;
  font-size: 0.95em;
}
.sidebar a .icon-placeholder {
  margin-right: 12px;
  font-size: 1.1em;
  width: 20px;
  text-align: center;
  color: #fff;
}
.sidebar a:hover { background-color: #228B22; color: #fff; }
.sidebar a:hover .icon-placeholder { color: #fff; }
.sidebar a.active,
.sidebar a.active-lesson,
.sidebar a.active-activity {
  background-color: #228B22;
  color: #fff;
  font-weight: 500;
}
.sidebar a.active .icon-placeholder,
.sidebar a.active-lesson .icon-placeholder,
.sidebar a.active-activity .icon-placeholder { color: #fff; }
.mobile-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 999;
}
@media (max-width: 1200px) {
  .sidebar.left, .sidebar.right { width: 28%; min-width: 250px; }
}
@media (max-width: 992px) {
  .sidebar.left, .sidebar.right { width: 32%; min-width: 220px; }
}
@media (max-width: 768px) {
  body { overflow: auto; height: auto; }
  .main-header { flex-direction: column; height: auto; padding: 15px; align-items: flex-start; position: relative; }
  .logo-container { margin-bottom: 10px; width: 100%; justify-content: space-between; }
  .mobile-buttons { display: flex; }
  .header-title { text-align: left; margin-bottom: 10px; }
  .main-nav { width: 100%; display: flex; justify-content: space-around; flex-wrap: wrap; gap: 5px; }
  .main-nav .nav-link { margin-left: 2px; margin-right: 2px; flex-grow: 1; text-align: center; font-size: 0.85em; padding: 6px 8px; }
  .main-layout { flex-direction: column; height: auto; overflow: visible; position: relative; }
  .sidebar.left, .sidebar.right {
    position: fixed;
    top: 0;
    width: 280px;
    height: 100vh;
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    display: block;
    min-width: unset;
    border-left: none;
    border-right: none;
    padding: 15px;
  }
  .sidebar.left { left: 0; }
  .sidebar.left.mobile-open { transform: translateX(0); }
  .sidebar.right { right: 0; left: auto; transform: translateX(100%); }
  .sidebar.right.mobile-open { transform: translateX(0); }
  .content-area { width: 100%; min-width: unset; height: auto; max-height: none; overflow-y: visible; border-left: none; border-right: none; padding: 15px; margin: 0; min-height: 60vh; }
  iframe#content-frame { min-height: 400px; width: 100%; }
  .mobile-overlay.active { display: block; }
}
@media (max-width: 480px) {
  .main-header { padding: 10px; }
  .logo { width: 35px; height: 35px; font-size: 1.1em; margin-right: 10px; }
  .header-title .module-name { font-size: 0.8em; }
  .header-title .content-title { font-size: 1em; }
  .main-nav .nav-link { font-size: 0.8em; padding: 5px 6px; }
  .sidebar.left, .sidebar.right { width: 100%; }
  .content-area { padding: 10px; }
  iframe#content-frame { min-height: 350px; }
}

/* Footer */
footer {
    background: rgba(255, 255, 255, 0.9);
    color: #228B22;
    text-align: center;
    padding: 20px;
    border-radius: 12px;
    margin-top: 20px;
    font-weight: 500;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

/* Botones y elementos interactivos */
button, .btn {
    background: linear-gradient(135deg, #228B22 0%, #32CD32 100%);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(34, 139, 34, 0.3);
}

button:hover, .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(34, 139, 34, 0.4);
    background: linear-gradient(135deg, #1a6b1a 0%, #228B22 100%);
}