:root {
  /* Colors */
  --color-primary: #1e40af;
  --color-primary-dark: #1e293b;
  --color-accent: rgb(1,186,239);
  --color-accent2: rgb(32,191,85);
  --color-bg: #fff;
  --color-border: #e5e7eb;
  --color-gray: #8a8f98;
  --color-gray2: #64748b;
  --color-bg-light: #f8fafc;
  --color-bg-lighter: #f0f4fa;
  --color-bg-banner: #e0e7ef;
  /* Spacing & Sizing */
  --header-height: 64px;
  --topics-nav-top: 64px;
  --border-radius-lg: 18px;
  --border-radius-md: 14px;
  --border-radius-sm: 8px;
  --border-width: 1.5px;
  --padding-main: 24px;
  --gap-main: 32px;
  --font-size-base: 1rem;
  --font-size-lg: 2rem;
  /* Shadows & Transitions */
  --shadow-card: 0 2px 8px rgba(30,64,175,0.08);
  --shadow-pop: 0 6px 20px rgba(1,186,239,0.13);
  --transition-fast: 0.2s;
  --transition-slow: 0.5s;
}

/* Reset and base styles */
html {
  scroll-behavior: smooth;
}
body {
    font-family: 'Heebo', 'Segoe UI', Arial, sans-serif;
    background: var(--color-bg);
    margin: 0;
    padding: 0;
    direction: rtl;
    color: var(--color-primary-dark);
  }
  body.class-page .site-header {
    position: static;
  }
  .site-header {
    width: 100vw;
    background: var(--color-bg);
    border-bottom: var(--border-width) solid var(--color-border);
    height: var(--header-height);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
  }
  .site-header-inner {
    display: flex;
    flex-direction: row-reverse;
    align-items: center;
    width: 100%;
    max-width: 1100px;
    margin: 0 auto;
    height: var(--header-height);
    justify-content: space-between;
  }
  .site-header-left {
    display: flex;
    align-items: center;
  }
  .site-header-icon {
    display: flex;
    align-items: center;
    margin-left: 12px;
  }
  .site-header-right {
    display: flex;
    align-items: center;
    gap: 12px;
  }
  .nav-btn {
    background: var(--color-bg);
    border: var(--border-width) solid var(--color-border);
    color: var(--color-primary-dark);
    border-radius: 999px;
    font-size: var(--font-size-base);
    padding: 0.5rem 1.2rem;
    margin-right: 8px;
    transition: all var(--transition-fast);
    box-shadow: none;
    outline: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    text-decoration: none;
    font-weight: 700;
    gap: 6px;
  }
  .nav-btn:hover {
    color: var(--color-bg);
    border-color: var(--color-primary);
  }
  .dropdown {
    position: relative;
    display: inline-block;
  }
  .dropdown-btn {
    background: var(--color-bg);
    border: var(--border-width) solid var(--color-border);
    color: var(--color-primary-dark);
    border-radius: 999px;
    font-size: var(--font-size-base);
    padding: 0.5rem 1.2rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all var(--transition-fast);
  }
  .dropdown-btn:hover, .dropdown-btn:focus {
    border-color: var(--color-primary);
  }
  .dropdown-content {
    display: none;
    position: absolute;
    top: 110%;
    right: 0;
    background: var(--color-bg);
    min-width: 180px;
    box-shadow: var(--shadow-card);
    border-radius: var(--border-radius-lg);
    border: var(--border-width) solid var(--color-border);
    z-index: 1000;
    padding: 8px 0;
  }
  .dropdown:hover .dropdown-content, .dropdown:focus-within .dropdown-content {
    display: block;
  }
  .dropdown-content a {
    color: var(--color-primary-dark);
    padding: 10px 24px;
    text-decoration: none;
    display: block;
    font-size: var(--font-size-base);
    font-weight: 500;
    border-radius: var(--border-radius-sm);
    transition: background var(--transition-fast), color var(--transition-fast);
  }
  .dropdown-content a.active, .dropdown-content a:hover {
    background: var(--color-bg-banner);
    color: var(--color-primary);
  }
  .site-main {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 var(--padding-main);
  }
  .welcome-block {
    text-align: center;
    margin: 48px 0 32px 0;
  }
  .welcome-title {
    font-size: 2.3rem;
    font-weight: 800;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
  }
  .welcome-desc {
    font-size: 1.15rem;
    color: var(--color-gray2);
    margin: 0;
  }
  .class-cards {
    display: flex;
    gap: var(--gap-main);
    justify-content: center;
    flex-wrap: wrap;
  }
  .class-card {
    background: var(--color-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-card);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    color: inherit;
    border: var(--border-width) solid var(--color-border);
    min-width: 380px;
    max-width: 480px;
    flex: 1 1 380px;
  }
  .class-card-banner {
    height: 160px;
    background-size: cover;
    background-position: center;
  }
  .class-card-content {
    padding: var(--padding-main);
  }
  .class-card-title-row {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-bottom: 12px;
  }
  .class-card-title {
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--color-primary);
    margin: 0;
  }
  .class-card-desc {
    font-size: var(--font-size-base);
    color: var(--color-gray2);
    margin: 0;
  }
  .class-card-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
  }
  .tag {
    white-space: nowrap;
    font-weight: 400;
    color: var(--color-primary-dark);
    background: var(--color-bg);
    border: var(--border-width) solid var(--color-border);
    border-radius: 999px;
    font-size: 0.95rem;
    padding: 0.5rem 0.7rem;
    display: inline-block;
    transition: all var(--transition-fast);
  }
  .class-card-meta {
    display: flex;
    gap: 16px;
    font-size: 0.95rem;
    color: var(--color-gray2);
    margin-top: 8px;
  }
  .class-banner-full {
    position: relative;
    min-height: 220px;
    background-size: cover;
    background-position: center;
    border-radius: var(--border-radius-lg);
    margin-bottom: var(--gap-main);
    display: flex;
    align-items: flex-end;
    overflow: hidden;
    margin-top:10px;
  }
  .class-banner-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(0deg, rgba(0,0,0,0.7) 1%, transparent 60%);
  }
  .class-banner-content {
    position: relative;
    z-index: 2;
    color: var(--color-bg);
    padding: 32px;
  }
  .class-banner-content h1 {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    color: var(--color-bg);
  }
  .class-banner-content p {
    font-size: 1.1rem;
    font-weight: 400;
    margin: 0;
    color: var(--color-bg-banner);
  }
  .topics-nav {
    display: flex;
    gap: 12px;
    background: var(--color-bg);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-card);
    padding: 18px 0 10px 0;
    margin: 0 auto var(--gap-main) auto;
    position: sticky;
    top: var(--topics-nav-top);
    z-index: 20;
    max-width: 1100px;
    justify-content: center;
  }
  
  /* On class pages, where navbar is not sticky, stick to the very top */
  body.class-page .topics-nav {
    top: 0;
  }
  
  /* On small screens, if navbar height changes, adjust as needed */
  @media (max-width: 600px) {
    .topics-nav {
      top: 56px;
    }
    body.class-page .topics-nav {
      top: 0;
    }
  }
  .topic-btn {
    font-family: inherit;
    font-size: 0.9rem;
    padding: 0.5rem 0.7rem;
    border-radius: 999px;
    border: 1.5px solid #e5e7eb;
    background: #fff;
    color: var(--color-primary-dark);
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border 0.2s;
    outline: none;
  }
  .topic-btn.active {
    color: rgb(255, 255, 255);
    box-shadow: rgba(1, 186, 239, 0.3) 0px 4px 15px;
    background: linear-gradient(135deg, rgb(1, 186, 239) 0%, rgb(32, 191, 85) 100%);
    border-color: rgb(1, 186, 239);
  }
  .topics-list {
    margin-bottom: 32px;
  }
  .topic-section {
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 2px 8px rgba(30,64,175,0.08);
    padding: 32px 24px;
    margin-bottom: 32px;
    border: 1.5px solid #e5e7eb;
    transition: border 0.5s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  }
  .topic-section:hover {
    border: 1.5px solid rgb(1,186,239);
  }
  .topic-section h2 {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    border-bottom: 3px solid rgb(1, 186, 239);
    margin: 0 0 24px 0;
    color: var(--color-primary-dark);
    padding-bottom: 8px;
    /* Remove flex, align-items, gap */
  }
  .accordion {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    overflow: visible;
  }
  @media (min-width: 700px) {
    .accordion {
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
    }
  }
  .lesson {
    background: linear-gradient(135deg, rgb(248, 249, 250) 0%, rgb(233, 236, 239) 100%);
    border-radius: 14px;
    box-shadow: 0 2px 8px rgba(30,64,175,0.08);
    border: 1.5px solid #e5e7eb;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    padding: 0;
    overflow: hidden;
    width: 100%;
    box-sizing: border-box;
    color: #111;
    scroll-margin-top: 128px; /* Increased for combined sticky header + topics-nav */
  }
  .lesson:hover {
    box-shadow: 0 6px 20px rgba(1,186,239,0.13);
    border: 2px solid rgb(1,186,239);
    transform: translateY(-2px);
  }
  .lesson-pop {
    box-shadow: 0 6px 20px rgba(1,186,239,0.13);
    border: 2px solid rgb(1,186,239);
    transform: translateY(-2px);
    transition: box-shadow 0.2s, border 0.2s, transform 0.2s;
  }
  .lesson-header {
    font-size: 1.1rem;
    font-weight: 500;
    color: #111;
    padding: 1.2rem;
    margin: 0;
    user-select: none;
    display: flex;
    align-items: center;
    gap: 0;
    justify-content: space-between;
  }
  .chevron {
    display: inline-block;
    transition: transform 0.2s;
    width: 1.2em;
    height: 1.2em;
    vertical-align: middle;
    filter: none;
  }
  .lesson.expanded .chevron {
    transform: rotate(180deg);
  }
  .lesson-content {
    display: none;
    background: #f8fafc;
    padding: 1.2rem;
    border-top: 1px solid #e5e7eb;
  }
  .lesson.expanded .lesson-content {
    display: block;
    animation: fadeIn 0.3s ease;
  }
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
  }
  .lesson-btn {
    background: #1e40af;
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 6px 16px;
    font-size: 1rem;
    margin-top: 8px;
    cursor: pointer;
    transition: background 0.2s;
    text-decoration: none;
    display: inline-block;
    font-weight: 700;
  }
  .lesson-btn:hover {
    background: #0f256e;
  }
  /* Icons (SVG or CSS) */
  .icon-home::before {
    content: "";
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%231e40af" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M3 10.5L12 4l9 6.5M5 10.5V19a1 1 0 001 1h3.5a.5.5 0 00.5-.5V15a1 1 0 011-1h2a1 1 0 011 1v4.5a.5.5 0 00.5.5H18a1 1 0 001-1v-8.5"/></svg>') center/contain no-repeat;
    vertical-align: middle;
  }
  .icon-book::before {
    content: "";
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%231e40af" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M4 19.5A2.5 2.5 0 016.5 17H20"/><path d="M4 4.5A2.5 2.5 0 016.5 7H20v13H6.5A2.5 2.5 0 014 17.5V4.5z"/></svg>') center/contain no-repeat;
    vertical-align: middle;
  }
  .icon-file::before {
    content: "";
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%231e40af" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8z"/><path d="M14 2v6h6"/></svg>') center/contain no-repeat;
    vertical-align: middle;
  }
  .icon-folder::before {
    content: "";
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%231e40af" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M3 7a2 2 0 012-2h5l2 2h7a2 2 0 012 2v7a2 2 0 01-2 2H5a2 2 0 01-2-2V7z"/></svg>') center/contain no-repeat;
    vertical-align: middle;
  }
  .chevron::before {
    content: "";
    display: inline-block;
    width: 1.2em;
    height: 1.2em;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%231e40af" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><polyline points="6 9 12 15 18 9"/></svg>') center/contain no-repeat;
    vertical-align: middle;
  }
  .lesson .icon-file::before,
  .lesson .icon-folder::before {
    filter: none;
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%23000" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8z"/><path d="M14 2v6h6"/></svg>') center/contain no-repeat;
  }
  .lesson .icon-folder::before {
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%23000" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M3 7a2 2 0 012-2h5l2 2h7a2 2 0 012 2v7a2 2 0 01-2 2H5a2 2 0 01-2-2V7z"/></svg>') center/contain no-repeat;
  }
  .lesson .chevron::before {
    background: url('data:image/svg+xml;utf8,<svg fill="none" stroke="%23000" stroke-width="2" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><polyline points="6 9 12 15 18 9"/></svg>') center/contain no-repeat;
  }
  .lesson-content a {
    color: #111;
  }
  @media (max-width: 900px) {
    .site-main, .container {
      padding: 0 8px;
    }
    .class-cards {
      flex-direction: column;
      gap: 24px;
    }
    .class-card {
      min-width: 0;
      max-width: 100%;
    }
  } 

@media (max-width: 700px) {
  .topics-nav {
    overflow-x: auto;
    white-space: nowrap;
    flex-wrap: nowrap;
    justify-content: flex-start;
    padding-right: 8px;
    padding-left: 8px;
    scrollbar-width: thin;
    scrollbar-color: #e5e7eb #fff;
  }
  .topics-nav::-webkit-scrollbar {
    height: 6px;
    background: #fff;
  }
  .topics-nav::-webkit-scrollbar-thumb {
    background: #e5e7eb;
    border-radius: 6px;
  }
  .topic-btn {
    flex: 0 0 auto;
    margin-left: 8px;
    margin-right: 0;
  }
  .lesson {
    scroll-margin-top: 96px; /* Adjust for mobile sticky area */
  }
} 

.lesson-folder .folder-row {
  display: flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
  padding: 2px 0;
  transition: background 0.2s;
}
.lesson-folder .folder-row:hover, .lesson-folder .folder-row:focus {
  background: #f0f4fa;
}
.folder-chevron {
  display: inline-block;
  width: 1em;
  margin-left: 0.5em;
  transition: transform 0.2s;
}
.lesson-folder.expanded > .folder-row .folder-chevron {
  transform: rotate(90deg);
}
.folder-content {
  margin-right: 2.2em;   /* aligns with folder icon + name */
  padding-right: 0.5em;  /* small extra space for clarity */
  border-right: none;
}
.lesson-folder .lesson-list {
  margin: 0;
  padding: 0;
}
.folder-icon {
  display: inline-flex;
  align-items: center;
  width: 1.5em;
  margin-left: 0.5em;
  transition: none;
}
.icon-folder-closed, .icon-folder-open {
  vertical-align: middle;
} 

.class-groups {
  /* Ensure the group container uses the same padding as the cards container */
  padding-right: 0;
}

.class-group-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #1e293b;
  margin: 32px 0 12px 0;
  letter-spacing: 0.5px;
  /* Add this: */
  padding-right: 24px; /* Match the .class-cards or .class-card margin/padding */
  /* Or use the same value as .class-cards { padding-right: ... } */
}

@media (max-width: 700px) {
  .class-group-title {
    padding-right: 0;
  }
}
.class-group-title.past {
  color: #8a8f98;
  font-weight: 600;
}
.dropdown-group-title {
  display: block;
  font-size: 0.95rem;
  font-weight: 600;
  color: #8a8f98;
  margin: 8px 0 2px 0;
  padding: 0 24px;
  cursor: default;
  pointer-events: none;
  user-select: none;
}
.dropdown-group-title.past {
  margin-top: 16px;
}