:root {
  --bg-primary-ocean-night: #001219;
  --bg-secondary-ocean-night: #002a3a;
  --text-primary-ocean-night: #e9f5f9;
  --text-secondary-ocean-night: #94d2bd;
  --accent-ocean-night: #00b4d8;
  --border-color-ocean-night: #005f73;
  --card-bg-ocean-night: rgba(0, 95, 115, 0.25);
  --header-bg-ocean-night: rgba(0, 18, 25, 0.88);
  --modal-bg-ocean-night: #00222f;
  --input-bg-ocean-night: rgba(255, 255, 255, 0.07);
  --input-border-ocean-night: rgba(255, 255, 255, 0.18);
  --btn-primary-text-ocean-night: #001219;
  --accent-rgb-ocean-night: 0, 180, 216;
  --success-color-ocean-night: #22c55e;
  --danger-color-ocean-night: #ef4444;
  --warning-color-ocean-night: #f59e0b;
  --success-rgb-ocean-night: 34, 197, 94;
  --danger-rgb-ocean-night: 239, 68, 68;
  --warning-rgb-ocean-night: 245, 158, 11;
  --bg-primary-bio-dark: #0D1B2A;
  --bg-secondary-bio-dark: #1B263B;
  --text-primary-bio-dark: #E0E1DD;
  --text-secondary-bio-dark: #A0B4D0;
  --accent-bio-dark: #40C9A2;
  --border-color-bio-dark: #415A77;
  --card-bg-bio-dark: rgba(65, 90, 119, 0.25);
  --header-bg-bio-dark: rgba(13, 27, 42, 0.88);
  --modal-bg-bio-dark: #182335;
  --input-bg-bio-dark: rgba(224, 225, 221, 0.07);
  --input-border-bio-dark: rgba(224, 225, 221, 0.18);
  --btn-primary-text-bio-dark: #0D1B2A;
  --accent-rgb-bio-dark: 64, 201, 162;
  --success-color-bio-dark: #34d399;
  --danger-color-bio-dark: #f87171;
  --warning-color-bio-dark: #fbbf24;
  --success-rgb-bio-dark: 52, 211, 153;
  --danger-rgb-bio-dark: 248, 113, 113;
  --warning-rgb-bio-dark: 251, 191, 36;
  --bg-primary-recycle-dark: #1a1a1a;
  --bg-secondary-recycle-dark: #2a2a2a;
  --text-primary-recycle-dark: #f5f5f5;
  --text-secondary-recycle-dark: #b0b0b0;
  --accent-recycle-dark: #70e000;
  --border-color-recycle-dark: #4a4a4a;
  --card-bg-recycle-dark: rgba(60, 60, 60, 0.35);
  --header-bg-recycle-dark: rgba(26, 26, 26, 0.88);
  --modal-bg-recycle-dark: #262626;
  --input-bg-recycle-dark: rgba(245, 245, 245, 0.07);
  --input-border-recycle-dark: rgba(245, 245, 245, 0.18);
  --btn-primary-text-recycle-dark: #1a1a1a;
  --accent-rgb-recycle-dark: 112, 224, 0;
  --success-color-recycle-dark: #4ade80;
  --danger-color-recycle-dark: #ef4444;
  --warning-color-recycle-dark: #facc15;
  --success-rgb-recycle-dark: 74, 222, 128;
  --danger-rgb-recycle-dark: 239, 68, 68;
  --warning-rgb-recycle-dark: 250, 204, 21;
  --bg-primary-clean-sky: #f0f9ff;
  --bg-secondary-clean-sky: #e0f2fe;
  --text-primary-clean-sky: #0c4a6e;
  --text-secondary-clean-sky: #387093;
  --accent-clean-sky: #0ea5e9;
  --border-color-clean-sky: #bae6fd;
  --card-bg-clean-sky: #ffffff;
  --header-bg-clean-sky: rgba(240, 249, 255, 0.88);
  --modal-bg-clean-sky: #ffffff;
  --input-bg-clean-sky: #ffffff;
  --input-border-clean-sky: #cbd5e1;
  --btn-primary-text-clean-sky: #ffffff;
  --accent-rgb-clean-sky: 14, 165, 233;
  --success-color-clean-sky: #16a34a;
  --danger-color-clean-sky: #dc2626;
  --warning-color-clean-sky: #d97706;
  --success-rgb-clean-sky: 22, 163, 74;
  --danger-rgb-clean-sky: 220, 38, 38;
  --warning-rgb-clean-sky: 217, 119, 6;
  --bg-primary-fresh-leaf: #f0fff4;
  --bg-secondary-fresh-leaf: #dcfce7;
  --text-primary-fresh-leaf: #166534;
  --text-secondary-fresh-leaf: #15803d;
  --accent-fresh-leaf: #22c55e;
  --border-color-fresh-leaf: #bbf7d0;
  --card-bg-fresh-leaf: #ffffff;
  --header-bg-fresh-leaf: rgba(240, 255, 244, 0.88);
  --modal-bg-fresh-leaf: #ffffff;
  --input-bg-fresh-leaf: #ffffff;
  --input-border-fresh-leaf: #a7f3d0;
  --btn-primary-text-fresh-leaf: #ffffff;
  --accent-rgb-fresh-leaf: 34, 197, 94;
  --success-color-fresh-leaf: #15803d;
  --danger-color-fresh-leaf: #b91c1c;
  --warning-color-fresh-leaf: #c2410c;
  --success-rgb-fresh-leaf: 21, 128, 61;
  --danger-rgb-fresh-leaf: 185, 28, 28;
  --warning-rgb-fresh-leaf: 194, 65, 12;
  --bg-primary-aqua-tech: #ecfeff;
  --bg-secondary-aqua-tech: #cffafe;
  --text-primary-aqua-tech: #0e7490;
  --text-secondary-aqua-tech: #155e75;
  --accent-aqua-tech: #06b6d4;
  --border-color-aqua-tech: #a5f3fc;
  --card-bg-aqua-tech: #ffffff;
  --header-bg-aqua-tech: rgba(236, 254, 255, 0.88);
  --modal-bg-aqua-tech: #ffffff;
  --input-bg-aqua-tech: #ffffff;
  --input-border-aqua-tech: #67e8f9;
  --btn-primary-text-aqua-tech: #ffffff;
  --accent-rgb-aqua-tech: 6, 182, 212;
  --success-color-aqua-tech: #059669;
  --danger-color-aqua-tech: #c2410c;
  --warning-color-aqua-tech: #b45309;
  --success-rgb-aqua-tech: 5, 150, 105;
  --danger-rgb-aqua-tech: 194, 65, 12;
  --warning-rgb-aqua-tech: 180, 83, 9;

  --color-bg-primary: var(--bg-primary-ocean-night);
  --color-bg-secondary: var(--bg-secondary-ocean-night);
  --color-text-primary: var(--text-primary-ocean-night);
  --color-text-secondary: var(--text-secondary-ocean-night);
  --color-accent: var(--accent-ocean-night);
  --color-border: var(--border-color-ocean-night);
  --color-card-bg: var(--card-bg-ocean-night);
  --color-header-bg: var(--header-bg-ocean-night);
  --color-modal-bg: var(--modal-bg-ocean-night);
  --color-input-bg: var(--input-bg-ocean-night);
  --color-input-border: var(--input-border-ocean-night);
  --color-btn-primary-text: var(--btn-primary-text-ocean-night);
  --color-accent-rgb: var(--accent-rgb-ocean-night);
  --color-success: var(--success-color-ocean-night);
  --color-danger: var(--danger-color-ocean-night);
  --color-warning: var(--warning-color-ocean-night);
  --color-success-rgb: var(--success-rgb-ocean-night);
  --color-danger-rgb: var(--danger-rgb-ocean-night);
  --color-warning-rgb: var(--warning-rgb-ocean-night);

  --font-family-primary: 'Alexandria', 'IBM Plex Sans Arabic', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
  --font-family-secondary: 'IBM Plex Sans Arabic', 'Alexandria', sans-serif;

  --border-radius-sm: 6px;
  --border-radius-md: 10px;
  --border-radius-lg: 16px;
  --border-radius-xl: 24px;
  --border-radius-pill: 9999px;

  --shadow-xs: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
  --shadow-sm: 0 2px 4px -1px rgba(0, 0, 0, 0.04), 0 1px 2px -1px rgba(0, 0, 0, 0.03);
  --shadow-md: 0 4px 8px -2px rgba(0, 0, 0, 0.06), 0 2px 4px -2px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.07), 0 4px 6px -4px rgba(0, 0, 0, 0.06);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.07);
  --shadow-inset: inset 0 2px 4px 0 rgba(0, 0, 0, 0.05);

  --transition-short: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-long: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);

  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0em;
  --letter-spacing-wide: 0.025em;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

body,
button,
input,
textarea,
select,
label {
  font-family: var(--font-family-primary), sans-serif;
}

body {
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.7;
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

.hidden {
  display: none !important;
}

.opacity-0 {
  opacity: 0;
}

.prose-custom {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-primary);
}

.prose-custom pre code.hljs {
  font-family: var(--font-family-primary), monospace;
  font-size: 1.05em !important;
  font-weight: 400;
  line-height: 1.6;
  padding: 1em;
  border-radius: var(--border-radius-md);
}

.prose-custom pre {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  overflow-x: auto;
  border-radius: var(--border-radius-md);
  position: relative;
}

.copy-code-button {
  position: absolute;
  top: 0.75em;
  right: 0.75em;
  background-color: rgba(var(--color-accent-rgb), 0.25);
  color: var(--color-accent);
  border: 1px solid rgba(var(--color-accent-rgb), 0.4);
  padding: 0.35em 0.7em;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  font-size: 0.85em;
  opacity: 0.7;
  transition: opacity var(--transition-short), background-color var(--transition-short), color var(--transition-short);
  display: flex;
  align-items: center;
  gap: 0.4em;
}

.copy-code-button:hover {
  opacity: 1;
  background-color: rgba(var(--color-accent-rgb), 0.4);
}

.copy-code-button i {
  font-size: 0.9em;
}

.copy-code-button.copied {
  background-color: rgba(var(--color-success-rgb), 0.5);
  color: var(--color-success);
  border-color: rgba(var(--color-success-rgb), 0.7);
}

.copy-code-button.copied .copy-text {
  color: var(--color-success);
}

.prose-custom.dir-rtl .copy-code-button {
  right: auto;
  left: 0.75em;
}

.prose-custom code:not(pre code.hljs) {
  font-family: var(--font-family-primary), monospace;
  font-size: 0.9em;
  padding: 0.2em 0.4em;
  margin: 0 0.2em;
  background-color: rgba(var(--color-accent-rgb), 0.1);
  color: var(--color-accent);
  border-radius: var(--border-radius-sm);
  word-wrap: break-word;
}

.container {
  width: 92%;
  max-width: 1280px;
  margin-right: auto;
  margin-left: auto;
  padding-right: 1rem;
  padding-left: 1rem;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-family-secondary);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-tight);
}

h1 {
  font-size: 2.25rem;
}

h2 {
  font-size: 1.875rem;
}

h3 {
  font-size: 1.5rem;
}

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: 1rem;
  color: var(--color-text-secondary);
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-short);
}

a:hover {
  filter: brightness(1.15);
}

strong {
  font-weight: 600;
  color: var(--color-text-primary);
}

.app-preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: var(--color-bg-primary);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  transition: opacity 0.5s ease-out 0.2s, visibility 0.5s ease-out 0.2s;
}

.preloader-logo-container {
  position: relative;
  margin-bottom: 1.5rem;
}

.preloader-logo {
  width: 70px;
  height: 70px;
  display: inline-block;
  animation: pulseLogo 1.8s infinite cubic-bezier(0.65, 0, 0.35, 1);
  background-color: var(--color-accent);
  mask-image: url(../assets/logo.png);
  -webkit-mask-image: url(../assets/logo.png);
  mask-size: contain;
  -webkit-mask-size: contain;
  mask-repeat: no-repeat;
  -webkit-mask-repeat: no-repeat;
  mask-position: center;
  -webkit-mask-position: center;
}

.preloader-spinner {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 90px;
  height: 90px;
  margin-top: -45px;
  margin-left: -45px;
  border: 3px solid transparent;
  border-top-color: var(--color-accent);
  border-right-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.app-preloader p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  letter-spacing: var(--letter-spacing-wide);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes pulseLogo {

  0%,
  100% {
    transform: scale(0.95);
    opacity: 0.8;
  }

  50% {
    transform: scale(1.05);
    opacity: 1;
  }
}

.page-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  transition: opacity 0.6s ease-in;
}

.main-header {
  background-color: var(--color-header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0.8rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid transparent;
  transition: var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.main-header.scrolled {
  box-shadow: var(--shadow-md);
  border-bottom-color: var(--color-border);
}

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

.logo-link {
  display: flex;
  align-items: center;
}

.logo-image-container {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-left: 0.6rem;
  transition: transform var(--transition-base);
}

.logo-image {
  height: 100%;
  width: 100%;
  object-fit: contain;
  transition: filter var(--transition-base);
  filter: brightness(0) saturate(100%) invert(55%) sepia(81%) saturate(1967%) hue-rotate(165deg) brightness(97%) contrast(101%);
}

.logo-link:hover .logo-image-container {
  transform: rotate(-8deg) scale(1.03);
}

.logo-text {
  font-family: var(--font-family-primary);
  font-size: 1.6rem;
  font-weight: 400;
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-tight);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.theme-selector {
  position: relative;
}

.theme-button {
  background-color: transparent;
  color: var(--color-text-secondary);
  border: 0px solid var(--color-border);
  padding: 0.5rem 0.9rem;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  transition: var(--transition-base);
  font-size: 0.85rem;
  font-weight: 600;
}

.theme-button:hover,
.theme-button.active {
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  box-shadow: 0 0 10px -2px rgba(var(--color-accent-rgb), 0.5);
}

.theme-button .icon {
  margin-left: 0.4rem;
  font-size: 0.9em;
}

.theme-palette-popup {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  background-color: var(--color-modal-bg);
  border-radius: var(--border-radius-md);
  padding: 0.75rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.6rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px) scale(0.98);
  transition: opacity var(--transition-short), visibility var(--transition-short), transform var(--transition-short);
  z-index: 1001;
}

.theme-palette-popup.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.theme-swatch {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition-short);
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: var(--shadow-xs);
}

.theme-swatch:hover {
  transform: scale(1.12);
  border-color: var(--color-accent);
}

.theme-swatch.active {
  border-color: var(--color-text-primary);
  transform: scale(1.08);
  box-shadow: 0 0 0 2px var(--color-text-primary);
}

.theme-swatch.active::after {
  content: '\f00c';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  color: var(--color-text-primary);
  font-size: 0.7rem;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.25rem;
}

.mobile-nav {
  display: none;
}

.main-content {
  flex-grow: 1;
  padding: 2.5rem 0 3.5rem;
}

.app-loader-main {
  text-align: center;
  padding: 3rem 0;
}

.loader-dots {
  width: 50px;
  height: 50px;
  border: 5px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 45%;
  animation: modernSpin 1s linear infinite;
  display: inline-block;
  margin-top: 0.5rem;
  margin-right: 48%;
}

@keyframes modernSpin {
  to {
    transform: rotate(360deg);
  }
}

.app-loader-main p {
  margin-top: 0.75rem;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.content-section {
  margin-bottom: 3.5rem;
  opacity: 0;
  transform: translateY(25px);
  animation: sectionFadeIn 0.6s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

.content-section.hidden {
  animation: none;
}

.content-section:nth-child(odd) {
  animation-delay: 0.1s;
}

.content-section:nth-child(even) {
  animation-delay: 0.2s;
}

@keyframes sectionFadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section-header {
  margin-bottom: 2rem;
  text-align: center;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  display: inline-flex;
  align-items: center;
  position: relative;
}

.section-title .section-icon {
  color: var(--color-accent);
  margin-left: 0.6rem;
  font-size: 0.85em;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--color-text-secondary);
  max-width: 550px;
  margin-right: auto;
  margin-left: auto;
  line-height: 1.8;
}

.breadcrumb-button {
  display: inline-flex;
  align-items: center;
  background-color: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  border: 1px solid transparent;
  padding: 0.5rem 1rem;
  margin-bottom: 1.8rem;
  margin-top: 1.8rem;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-base);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-sm);
}

.breadcrumb-button:hover {
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.icon-breadcrumb {
  margin-left: 0.4rem;
}

.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 1.8rem;
}

.subject-card {
  background-color: var(--color-card-bg);
  border: 1px solid transparent;
  border-radius: var(--border-radius-lg);
  padding: 1.8rem 1.5rem;
  text-align: center;
  transition: var(--transition-base);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.subject-card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(var(--color-accent-rgb), 0.1) 0%, rgba(var(--color-accent-rgb), 0) 70%);
  transition: opacity 0.5s;
  opacity: 0;
  z-index: 0;
}

.subject-card:hover::before {
  opacity: 1;
  animation: rotateGradient 5s linear infinite;
}

@keyframes rotateGradient {
  from {
    transform: rotate(0deg);
  }

  to {
    transform: rotate(360deg);
  }
}

.subject-card>* {
  position: relative;
  z-index: 1;
}

.subject-card:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: var(--shadow-lg), 0 0 20px -5px rgba(var(--color-accent-rgb), 0.3);
  border-color: var(--color-accent);
}

.subject-card-icon-container {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background-color: rgba(var(--color-accent-rgb), 0.12);
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 1rem;
  transition: var(--transition-base);
}

.subject-card:hover .subject-card-icon-container {
  background-color: var(--color-accent);
  transform: scale(1.1);
  box-shadow: 0 0 15px rgba(var(--color-accent-rgb), 0.4);
}

.subject-card-icon {
  font-size: 1.8rem;
  color: var(--color-accent);
  transition: var(--transition-base);
}

.subject-card:hover .subject-card-icon {
  color: var(--color-btn-primary-text);
}

.subject-card-name {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 0.3rem;
}

.subject-card-lectures {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
}

.lectures-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.lecture-item {
  background-color: var(--color-card-bg);
  border: 1px solid transparent;
  border-radius: var(--border-radius-md);
  padding: 1rem 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  transition: var(--transition-base);
  box-shadow: var(--shadow-sm);
  border-right: 4px solid transparent;
}

.lecture-item:hover {
  border-right-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.05);
  transform: translateX(5px);
  box-shadow: var(--shadow-md);
}

.lecture-item-name {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--color-text-primary);
}

.lecture-item-arrow {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  transition: var(--transition-base);
}

.lecture-item:hover .lecture-item-arrow {
  color: var(--color-accent);
  transform: translateX(4px);
}

.lecture-header-card {
  background-color: var(--color-bg-secondary);
  padding: 2rem 1.5rem;
  border-radius: var(--border-radius-lg);
  margin-bottom: 2rem;
  box-shadow: var(--shadow-lg);
  text-align: center;
  position: relative;
}

.lecture-icon-bg {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem auto;
  box-shadow: 0 0 20px -5px rgba(var(--color-accent-rgb), 0.6);
}

.lecture-icon-bg:hover {
  transform: scale(1.03);
}

.lecture-main-icon {
  font-size: 2.5rem;
}

.lecture-title-main {
  font-size: 1.7rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

.lecture-actions-bar {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.action-button {
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  border: none;
  padding: 0.7rem 1.4rem;
  border-radius: var(--border-radius-pill);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  transition: var(--transition-base);
  box-shadow: var(--shadow-sm);
}

.action-button i {
  transform: scale(1.4);
}

.action-button:hover {
  filter: brightness(1.1);
  transform: translateY(-2px) scale(1.02);
  box-shadow: var(--shadow-md), 0 0 12px -3px rgba(var(--color-accent-rgb), 0.4);
}

.action-button.active-action {
  filter: brightness(0.9);
  box-shadow: var(--shadow-inset), 0 0 8px -2px rgba(var(--color-accent-rgb), 0.3);
  transform: translateY(0) scale(1);
}

.button-icon-leading {
  margin-left: 0.5rem;
}

.button-icon-trailing {
  margin-right: 0.5rem;
}

.initial-content-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  color: var(--color-text-secondary);
  text-align: center;
  padding: 2rem;
  transition: opacity 0.3s ease-in-out;
}

.initial-content-placeholder .placeholder-icon {
  font-size: 2.8rem;
  margin-bottom: 1.25rem;
  color: var(--color-accent);
  opacity: 0.6;
  animation: gentleBounce 2s infinite ease-in-out;
}

.initial-content-placeholder p {
  font-size: 1.05rem;
  font-weight: 500;
}

@keyframes gentleBounce {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-8px);
  }
}

.content-display {
  background-color: var(--color-card-bg);
  padding: 1.5rem 2rem;
  border-radius: var(--border-radius-lg);
  border: 1px solid transparent;
  min-height: 200px;
  box-shadow: var(--shadow-md);
  font-size: 1rem;
  margin-bottom: 2rem;
  transition: opacity 0.4s ease-in-out, transform 0.4s ease-in-out, max-height 0.4s ease-in-out, padding 0.4s ease-in-out, margin 0.4s ease-in-out, border 0.4s ease-in-out;
}

.content-display.hidden {
  opacity: 0;
  transform: translateY(15px);
  pointer-events: none;
  min-height: 0;
  padding: 0;
  margin-bottom: 0;
  border-width: 0;
  overflow: hidden;
  max-height: 0;
}

.content-display.visible-content {
  opacity: 1;
  transform: translateY(0);
  min-height: 200px;
  max-height: none;
  padding: 1.5rem 2rem;
  margin-bottom: 2rem;
  border-width: 1px;
}

.content-display.test-mode {
  padding: 1rem;
}

.content-display .prose-custom h1,
.content-display .prose-custom h2,
.content-display .prose-custom h3 {
  margin-top: 1.5em;
  margin-bottom: 0.6em;
  line-height: 1.4;
  font-family: var(--font-family-secondary) !important;
}

.content-display .prose-custom p {
  margin-bottom: 1em;
  font-family: var(--font-family-primary) !important;
}

.content-display .prose-custom ul,
.content-display .prose-custom ol {
  margin-bottom: 1em;
  margin-right: 1.5em;
  font-family: var(--font-family-primary) !important;
}

.content-display .prose-custom li>p {
  margin-bottom: 0.3em;
}

.content-display .prose-custom code {
  background-color: rgba(var(--color-accent-rgb), 0.1);
  color: var(--color-accent);
  padding: 0.2em 0.4em;
  border-radius: var(--border-radius-sm);
  font-size: 0.9em;
}

.content-display .prose-custom pre {
  background-color: var(--color-bg-secondary);
  padding: 1em;
  border-radius: var(--border-radius-md);
  overflow-x: auto;
  border: 1px solid transparent;
  margin: 1.5em 0;
}

.content-display .prose-custom pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: 0.85em;
}

.content-display .prose-custom blockquote {
  border-right: 3px solid var(--color-accent);
  padding-right: 1em;
  margin: 1.5em 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

.pdf-link-item {
  display: flex;
  align-items: center;
  padding: 0.85rem 1.25rem;
  margin-top: 1rem;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius-md);
  transition: var(--transition-base);
  text-decoration: none;
}

.pdf-link-item:hover {
  border-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

.pdf-link-item .icon {
  color: var(--color-danger);
  font-size: 1.3rem;
  margin-left: 0.75rem;
}

.pdf-link-item .name {
  flex-grow: 1;
  color: var(--color-text-primary);
  font-weight: 500;
  font-size: 0.95rem;
}

.pdf-link-item .external-icon {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  transition: transform 0.2s ease-out;
}

.pdf-link-item:hover .external-icon {
  transform: scale(1.1) translateX(-2px);
  color: var(--color-accent);
}

.error-message-card {
  background-color: rgba(var(--color-danger-rgb), 0.1);
  border: 1px solid rgba(var(--color-danger-rgb), 0.3);
  color: var(--color-danger);
  padding: 1.5rem;
  border-radius: var(--border-radius-md);
  text-align: center;
  margin: 2rem auto;
  max-width: 500px;
}

.error-message-card .error-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
  display: block;
}

.error-message-card p {
  margin-bottom: 1rem;
  color: var(--color-danger) !important;
}

.test-history-container {
  background-color: var(--color-bg-secondary);
  padding: 0;
  border-radius: var(--border-radius-md);
  margin-bottom: 1.8rem;
  border: 1px solid transparent;
  box-shadow: var(--shadow-sm);
  overflow: hidden;

}

.test-history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  transition: background-color var(--transition-short);
}

.test-history-header:hover {
  background-color: rgba(var(--color-accent-rgb), 0.05);
}

.test-history-header h4 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
  display: flex;
  align-items: center;
}

.test-history-header h4 i {
  margin-left: 0.5rem;
  color: var(--color-accent);
}

.history-toggle-icon {
  color: var(--color-text-secondary);
  transition: transform 0.3s ease-in-out;
  font-size: 1rem;
}

.test-history-content {
  padding: 0.75rem 1.25rem 1.25rem 1.25rem;
  max-height: 500px;
  overflow-y: auto;
  transition: max-height 0.4s ease-in-out, padding 0.4s ease-in-out, opacity 0.3s ease-in-out;
  border-top: 1px solid var(--color-border);
  opacity: 1;
}

.test-history-content.collapsed {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
  overflow: hidden;
  opacity: 0;
  border-top-color: transparent;
}

.test-history-content ul {
  list-style: none;
  padding-right: 0.5rem;
  margin-bottom: 0;
}

.test-history-content li {
  background-color: var(--color-card-bg);
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-sm);
  margin-bottom: 0.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  border: 1px solid transparent;
  transition: var(--transition-short);
}

.test-history-content li:hover {
  border-color: var(--color-accent);
}

.test-history-content li .history-date {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

.test-history-content li .history-score {
  font-weight: 600;
  color: var(--color-accent);
}

.test-history-content .no-history {
  color: var(--color-text-secondary);
  text-align: center;
  padding: 1rem 0;
  font-style: italic;
  margin-bottom: 0;
}


.test-start-screen {
  text-align: center;
  padding: 2rem 1rem;
  border-radius: var(--border-radius-lg);
  background-color: var(--color-bg-secondary);
  animation: fadeInTestScreen 0.5s ease-out;
}

@keyframes fadeInTestScreen {
  from {
    opacity: 0;
    transform: scale(0.95);
  }

  to {
    opacity: 1;
    transform: scale(1);
  }
}

.welcome-user-container {
  margin-bottom: 1.25rem;
  animation: fadeInWelcome 0.6s ease-out forwards;
}

@keyframes fadeInWelcome {
  from {
    opacity: 0;
    transform: translateY(-15px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.welcome-message-custom {
  text-align: center;
  font-size: 1.25rem;
  color: var(--color-text-primary);
  background-color: var(--color-card-bg);
  padding: 0.8rem 1.2rem;
  border-radius: var(--border-radius-lg);
  border: 1px solid transparent;
  box-shadow: var(--shadow-md);
}

.user-name-highlight {
  font-weight: 700;
  color: var(--color-accent);
  font-size: 1.1em;
}

.test-start-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 1rem;
}

.test-start-instructions {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: 1.5rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.test-start-meta {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
}

.button-large {
  padding: 0.8rem 2rem;
  font-size: 1.1rem;
}

.question-view {
  animation: fadeInTestScreen 0.4s ease-out;
}

.question-progress-bar-container {
  height: 8px;
  background-color: var(--color-border);
  border-radius: var(--border-radius-pill);
  margin-bottom: 1.5rem;
  overflow: hidden;
}

.question-progress-bar {
  height: 100%;
  width: 0%;
  background-color: var(--color-success);
  border-radius: var(--border-radius-pill);
  transition: width 0.3s ease-out;
}

.question-header-area {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  padding: 0 0.5rem;
}

.current-question-number {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.live-timer {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.live-timer.hidden {
  display: none !important;
}

.question-text-dynamic {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 2rem;
  line-height: 1.7;
  padding: 1rem;
  background-color: var(--color-bg-secondary);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-sm);
}

.question-view.prose-custom .question-text-dynamic {
  background-color: transparent;
  padding: 0;
  box-shadow: none;
  font-size: 1rem;
  font-weight: normal;
  color: var(--color-text-primary);
}

.question-view.prose-custom .question-text-dynamic p,
.question-view.prose-custom .question-text-dynamic ul,
.question-view.prose-custom .question-text-dynamic ol {
  font-size: 1rem;
  color: var(--color-text-primary);
}


.options-area-dynamic {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 768px) {
  .options-area-dynamic.grid-cols-2 {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
}

.option-button {
  display: block;
  width: 100%;
  padding: 0.9rem 1.25rem;
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text-primary);
  background-color: var(--color-card-bg);
  border: 2px solid transparent;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: var(--transition-base);
  position: relative;
  text-align: initial;
}

.question-view.prose-custom .option-button {
  text-align: initial;
}

.question-view.prose-custom .option-button p {
  margin-bottom: 0;
  font-size: 0.95rem;
  color: var(--color-text-primary);
}

.question-view.prose-custom .option-button code {
  font-size: 0.85em;
}


.option-button:hover:not(:disabled) {
  border-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}

.option-button:disabled {
  cursor: not-allowed;
  opacity: 0.8;
}

.option-button.selected {
  border-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.15);
}

.option-button.correct {
  border-color: var(--color-success) !important;
  background-color: rgba(var(--color-success-rgb), 0.15) !important;
  color: var(--color-success) !important;
  font-weight: 600;
}

.question-view.prose-custom .option-button.correct p,
.question-view.prose-custom .option-button.correct code {
  color: var(--color-success) !important;
}


.option-button.incorrect {
  border-color: var(--color-danger) !important;
  background-color: rgba(var(--color-danger-rgb), 0.15) !important;
  color: var(--color-danger) !important;
  opacity: 0.7;
}

.question-view.prose-custom .option-button.incorrect p,
.question-view.prose-custom .option-button.incorrect code {
  color: var(--color-danger) !important;
}


.option-button.actual-correct {
  box-shadow: 0 0 0 2px var(--color-success) inset;
}

.option-button .feedback-icon {
  margin-right: 0.75rem;
  font-size: 1.1em;
}

.question-feedback-area {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-md);
  font-weight: 500;
  min-height: 40px;
}

.question-view.prose-custom .question-feedback-area strong code {
  background-color: transparent;
  padding: 0;
  margin: 0;
}


.question-feedback-area.correct-feedback {
  background-color: rgba(var(--color-success-rgb), 0.1);
  color: var(--color-success);
  border: 1px solid rgba(var(--color-success-rgb), 0.3);
  animation: feedbackPopIn 0.3s ease-out;
}

.question-feedback-area.incorrect-feedback {
  background-color: rgba(var(--color-danger-rgb), 0.1);
  color: var(--color-danger);
  border: 1px solid rgba(var(--color-danger-rgb), 0.3);
  animation: feedbackPopIn 0.3s ease-out;
}

.question-feedback-area.warning-feedback {
  background-color: rgba(var(--color-warning-rgb), 0.1);
  color: var(--color-warning);
  border: 1px solid rgba(var(--color-warning-rgb), 0.3);
  animation: feedbackPopIn 0.3s ease-out;
}

.question-feedback-area.hidden {
  display: none;
}

.question-explanation-area {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-md);
  background-color: rgba(var(--color-accent-rgb), 0.05);
  border: 1px solid transparent;
  color: var(--color-text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  animation: feedbackPopIn 0.3s ease-out;
}

.question-view.prose-custom .question-explanation-area div p,
.question-view.prose-custom .question-explanation-area div ul,
.question-view.prose-custom .question-explanation-area div ol {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.question-explanation-area:hover {
  transform: scale(1.02);
}

.question-explanation-area.hidden {
  display: none;
}

.question-explanation-area .explanation-title {
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
}

.question-explanation-area .explanation-title i {
  margin-left: 0.4rem;
  font-size: 1em;
}

@keyframes feedbackPopIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}


.test-navigation {
  margin-top: 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.question-counter {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.test-result-container {
  text-align: center;
  padding: 2rem 1.5rem;
  background-color: var(--color-card-bg);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  animation: fadeInTestScreen 0.5s ease-out;
  margin-top: 0 !important;
}

.result-icon-container {
  width: 100px;
  height: 100px;
  margin: 0 auto 1.5rem auto;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
}

.result-icon-container.passed {
  background-color: rgba(var(--color-success-rgb), 0.15);
  color: var(--color-success);
}

.result-icon-container.failed {
  background-color: rgba(var(--color-warning-rgb), 0.15);
  color: var(--color-warning);
}

.result-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 0.5rem;
}

.result-score-text {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

.result-score-text .score-value {
  font-weight: 700;
  font-size: 1.5em;
  color: var(--color-accent);
}

.result-percentage {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-success);
  margin-bottom: 1.5rem;
}

.result-message {
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
  line-height: 1.8;
}

.result-time-taken {
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin-top: 0.75rem;
  margin-bottom: 1rem;
}

.result-time-taken span {
  font-weight: 600;
  color: var(--color-accent);
}

.result-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.button {
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius-pill);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition-base);
  border: 1px solid transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  white-space: nowrap;
}

.button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
  filter: none !important;
}

.button-primary {
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  box-shadow: var(--shadow-sm);
}

.button-primary i {
  transform: scale(1.4);
  margin-right: 10px;
}

.button-primary:hover:not(:disabled) {
  filter: brightness(1.12);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md), 0 0 10px -3px rgba(var(--color-accent-rgb), 0.3);
}

.button-secondary {
  background-color: var(--color-card-bg);
  color: var(--color-text-primary);
  border-color: transparent;
  box-shadow: var(--shadow-xs);
}

.button-secondary i {
  transform: scale(1.4);
  margin-left: 10px;
}

.button-secondary:hover:not(:disabled) {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.05);
}

.button-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
}

.button-ghost:hover:not(:disabled) {
  background-color: rgba(var(--color-accent-rgb), 0.1);
  color: var(--color-accent);
}

.button-success {
  background-color: var(--color-success);
  color: white;
  box-shadow: var(--shadow-sm);
}

.button-success:hover:not(:disabled) {
  filter: brightness(1.1);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.button-full-width {
  width: 100%;
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1050;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity var(--transition-base);
  pointer-events: none;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-content-card {
  background-color: var(--color-modal-bg);
  border-radius: var(--border-radius-xl);
  padding: 2rem 2.5rem;
  max-width: 460px;
  width: 90%;
  box-shadow: var(--shadow-xl);
  border: 1px solid transparent;
  position: relative;
  transform: translateY(20px) scale(0.98);
  opacity: 0;
  transition: var(--transition-base);
}

.modal-overlay.active .modal-content-card {
  transform: translateY(0) scale(1);
  opacity: 1;
}

.modal-close-button {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: none;
  border: none;
  color: var(--color-text-secondary);
  font-size: 1.3rem;
  cursor: pointer;
  padding: 0.3rem;
  line-height: 1;
  border-radius: 50%;
  transition: var(--transition-short);
}

.modal-close-button:hover {
  color: var(--color-text-primary);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}

.modal-header-icon {
  text-align: center;
  margin-bottom: 1rem;
}

.modal-header-icon i {
  font-size: 2.8rem;
  color: var(--color-accent);
  padding: 0.8rem;
  background-color: rgba(var(--color-accent-rgb), 0.1);
  border-radius: 50%;
  display: inline-block;
  line-height: 1;
}

.modal-title-text {
  font-family: var(--font-family-secondary);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-text-primary);
  text-align: center;
  margin-bottom: 0.5rem;
}

.modal-description-text {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-bottom: 1.8rem;
  text-align: center;
  line-height: 1.7;
}

.modal-form-layout .form-field {
  margin-bottom: 1.2rem;
}

.modal-form-layout .form-label-text {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: 0.4rem;
}

.input-with-icon {
  position: relative;
}

.input-with-icon .input-icon {
  position: absolute;
  top: 50%;
  right: 0.8rem;
  transform: translateY(-50%);
  color: var(--color-text-secondary);
  font-size: 0.9em;
}

.modal-form-layout .form-input-field {
  width: 100%;
  padding: 0.7rem 1rem;
  padding-right: 2.2rem;
  border-radius: var(--border-radius-md);
  background-color: var(--color-input-bg);
  border: 1px solid var(--color-input-border);
  color: var(--color-text-primary);
  font-size: 0.95rem;
  transition: var(--transition-base);
  box-shadow: var(--shadow-inset);
}

.modal-form-layout .form-input-field:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: var(--shadow-inset), 0 0 0 3px rgba(var(--color-accent-rgb), 0.2);
}

.form-error-message {
  background-color: rgba(var(--color-danger-rgb), 0.1);
  border: 1px solid rgba(var(--color-danger-rgb), 0.3);
  color: var(--color-danger);
  padding: 0.7rem 1rem;
  border-radius: var(--border-radius-md);
  font-size: 0.8rem;
  margin-top: 0.5rem;
  display: flex;
  align-items: center;
}

.form-error-message::before {
  content: '\f071';
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  margin-left: 0.5rem;
}

.modal-actions-buttons {
  display: flex;
  gap: 0.8rem;
  margin-top: 1.8rem;
  justify-content: flex-end;
}

.main-footer-custom {
  background-color: var(--color-bg-secondary);
  color: var(--color-text-secondary);
  padding: 2.5rem 0 1.5rem;
  border-top: 1px solid transparent;
  margin-top: auto;
  font-size: 0.9rem;
}

.footer-main-content {
  text-align: center;
  margin-bottom: 1.5rem;
  padding: 0 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.footer-logo {
  width: 40px;
  height: 40px;
  display: inline-block;
  background-color: var(--color-accent);
  mask-image: url(../assets/logo.png);
  -webkit-mask-image: url(../assets/logo.png);
  mask-size: contain;
  -webkit-mask-size: contain;
  mask-repeat: no-repeat;
  -webkit-mask-repeat: no-repeat;
  mask-position: center;
  -webkit-mask-position: center;
  transition: background-color 0.5s ease;
}

.footer-team-name {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
}

.footer-copyright {
  text-align: center;
  font-size: 0.8rem;
  padding-top: 1rem;
  line-break: auto;
  direction: ltr;
  margin-top: 1rem;
}

.footer-copyright p {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
}

.footer-heartbeat {
  color: var(--color-accent);
  animation: heartbeat 1.5s infinite ease-in-out;
  display: inline-block;
  font-size: 1rem;
}

@keyframes heartbeat {

  0%,
  100% {
    transform: scale(1);
  }

  50% {
    transform: scale(1.2);
  }
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-bg-secondary);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb {
  background: var(--color-accent);
  border-radius: 10px;
  border: 2px solid var(--color-bg-secondary);
}

::-webkit-scrollbar-thumb:hover {
  background: color-mix(in srgb, var(--color-accent) 80%, black);
}

.custom-navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 0.5rem 0;
  margin-top: 0.3rem;
  background-color: transparent;
  backdrop-filter: blur(0px);
  -webkit-backdrop-filter: blur(0px);
  transition: background-color 0.3s ease-in-out, backdrop-filter 0.3s ease-in-out, transform 0.3s ease-out, box-shadow var(--transition-base), border-color var(--transition-base), padding 0.3s ease-in-out;
}

.custom-navbar.navbar-scrolled {
  background-color: var(--color-header-bg);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  border-bottom: 0px solid var(--color-border);
  display: none;
}

.custom-navbar.navbar-hidden {
  transform: translateY(-100%);
}

.navbar-content-grid {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-logo-link {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.navbar-logo-icon {
  width: 28px;
  height: 28px;
  margin-left: 0.5rem;
}

.navbar-logo-text {
  font-family: var(--font-family-primary);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--color-text-primary);
  letter-spacing: var(--letter-spacing-tight);
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.theme-button-icononly {
  background: none;
  border: 0px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  padding: 0.4rem 0.6rem;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: var(--transition-base);
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-button-icononly:hover,
.theme-button-icononly.active {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}

.mobile-menu-toggle-icononly {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  padding: 0.4rem 0.6rem;
  border-radius: var(--border-radius-md);
  cursor: pointer;
  transition: var(--transition-base);
}

.mobile-menu-toggle-icononly:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}


.mobile-menu-panel {
  background-color: var(--color-header-bg);
  backdrop-filter: blur(15px);
  -webkit-backdrop-filter: blur(15px);
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
  border-top: 1px solid var(--color-border);
}

.mobile-menu-panel.hidden {
  display: none;
}

.logo-svg {
  background-color: var(--color-accent);
  transition: background-color 0.5s ease, transform 0.3s ease, filter 0.3s ease;
  mask-image: url(../assets/logo.png);
  -webkit-mask-image: url(../assets/logo.png);
  mask-size: contain;
  -webkit-mask-size: contain;
  mask-repeat: no-repeat;
  -webkit-mask-repeat: no-repeat;
  mask-position: center;
  -webkit-mask-position: center;
}

.navbar-logo-icon.logo-svg {
  transform: scale(1.7);
}

.navbar-logo-link:hover .navbar-logo-icon.logo-svg {
  transform: scale(1.8) rotate(5deg);
  filter: drop-shadow(0 0 6px var(--color-accent));
}


@media (max-width: 992px) {
  .section-title {
    font-size: 1.8rem;
  }

  .lecture-title-main {
    font-size: 1.5rem;
  }

  .subjects-grid {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }

  .container {
    width: 95%;
    padding-right: 0.75rem;
    padding-left: 0.75rem;
  }

  .custom-navbar.navbar-static-mobile {
    position: relative !important;
    transform: none !important;
    margin-top: 0 !important;
    background-color: var(--color-header-bg) !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05) !important;
    border-bottom: 0px solid var(--color-border) !important;
    padding-top: 0.75rem !important;
    padding-bottom: 0.75rem !important;
    transition: none !important;
  }

  .main-header {
    padding: 0.6rem 0;
  }

  .logo-text {
    font-size: 1.4rem;
  }

  .logo-image {
    height: 34px;
  }

  .navbar-logo-text {
    font-size: 1.25rem;
  }

  .navbar-logo-icon {
    width: 24px;
    height: 24px;
  }

  .navbar-logo-icon.logo-svg {
    transform: scale(1.6);
  }

  .theme-button-text {
    display: none;
  }

  .theme-button .icon {
    margin-left: 0;
  }

  .mobile-menu-toggle {
    display: block;
  }

  .mobile-menu-toggle-icononly {
    display: block;
  }


  .section-title {
    font-size: 1.6rem;
  }

  .section-subtitle {
    font-size: 0.95rem;
  }

  .breadcrumb-button {
    margin-bottom: 1.5rem;
    margin-top: 1.5rem;
    font-size: 0.8rem;
  }

  .lecture-header-card {
    padding: 1.5rem;
  }

  .lecture-actions-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .action-button {
    width: 100%;
    justify-content: center;
  }

  .content-display {
    padding: 1.25rem;
  }

  .test-navigation {
    flex-direction: column;
    gap: 0.8rem;
  }

  .test-navigation .button {
    width: 100%;
  }

  .modal-content-card {
    padding: 1.5rem;
  }

  .modal-title-text {
    font-size: 1.25rem;
  }

  .modal-actions-buttons {
    flex-direction: column-reverse;
  }

  .modal-actions-buttons .button {
    width: 100%;
  }

  .footer-main-content {
    margin-bottom: 1rem;
  }
}

@media (max-width: 480px) {
  .subjects-grid {
    grid-template-columns: 1fr;
  }

  .action-button {
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
  }

  .button {
    padding: 0.65rem 1.2rem;
    font-size: 0.9rem;
  }

  .modal-content-card {
    padding: 1.5rem 1.2rem;
  }

  .navbar-actions {
    gap: 0.3rem;
  }

  .theme-button-icononly,
  .mobile-menu-toggle-icononly {
    padding: 0.3rem 0.5rem;
    font-size: 1rem;
  }

  .navbar-logo-text {
    display: none;
  }

  .navbar-logo-icon {
    margin-left: 0;
  }

}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

.dir-rtl {
  direction: rtl !important;
  text-align: right;
}

.dir-ltr {
  direction: ltr !important;
  text-align: left;
}

@media (max-width: 768px) {
  mjx-container {
    display: inline-flex !important;
    flex-wrap: wrap;
    overflow-x: auto !important;
    overflow-y: hidden !important;
    max-width: 100%;
    -webkit-overflow-scrolling: touch;
  }
}

.video-container {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  max-width: 100%;
  background: #000;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}


.custom-audio-player-container {
  background-color: var(--color-bg-secondary);
  border-radius: var(--border-radius-lg);
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
  width: 100%;
  overflow: hidden;
  margin-top: 1.5rem;
  margin-bottom: 1.5rem;
}

.audio-element {
  display: none;
}

.play-pause-btn {
  background-color: var(--color-accent);
  color: var(--color-btn-primary-text);
  width: 45px;
  height: 45px;
  border-radius: 50%;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-base);
  flex-shrink: 0;
  box-shadow: 0 0 10px -2px rgba(var(--color-accent-rgb), 0.5);
}

.play-pause-btn:hover {
  filter: brightness(1.15);
  transform: scale(1.05);
}

.play-pause-btn .icon-play,
.play-pause-btn .icon-pause {
  font-size: 1.1rem;
}

.audio-controls-group {
  display: flex;
  flex-direction: column;
  width: 100%;
  gap: 0.5rem;
}

.time-and-progress-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
}

.current-time,
.total-duration {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  font-family: var(--font-family-secondary);
  min-width: 35px;
  text-align: center;
}

.progress-bar-container {
  width: 100%;
  height: 8px;
  background-color: rgba(var(--color-accent-rgb), 0.1);
  border-radius: var(--border-radius-pill);
  cursor: pointer;
  position: relative;
}

.progress-track,
.progress-filled {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  border-radius: var(--border-radius-pill);
}

.progress-track {
  background-color: var(--color-border);
  width: 100%;
}

.progress-filled {
  background-color: var(--color-accent);
  width: 0%;
  transition: width 0.1s linear;
}

.progress-thumb {
  position: absolute;
  top: 50%;
  left: 0%;
  width: 16px;
  height: 16px;
  background-color: var(--color-accent);
  border-radius: 50%;
  transform: translateY(-50%) scale(0);
  transition: var(--transition-short);
  box-shadow: 0 0 5px rgba(0,0,0,0.2);
  border: 2px solid var(--color-btn-primary-text);
}

.progress-bar-container:hover .progress-thumb {
  transform: translateY(-50%) scale(1);
}

.volume-and-title-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    gap: 1rem;
}

.audio-title-wrapper {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    flex-grow: 1;
}

.audio-title {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-primary);
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
}

.volume-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.volume-btn {
  background: none;
  border: none;
  color: var(--color-text-secondary);
  font-size: 1rem;
  cursor: pointer;
  padding: 0.3rem;
  transition: var(--transition-short);
  border-radius: 50%;
}

.volume-btn:hover {
  color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}

.volume-slider-container {
  width: 80px;
  height: 5px;
  background-color: var(--color-border);
  border-radius: var(--border-radius-pill);
  cursor: pointer;
  position: relative;
}

.volume-filled {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 100%;
  background-color: var(--color-text-secondary);
  border-radius: var(--border-radius-pill);
  transition: width 0.1s linear;
}

.volume-control:hover .volume-filled, .volume-control:focus-within .volume-filled {
  background-color: var(--color-accent);
}


@media (max-width: 768px) {
  .custom-audio-player-container {
    padding: 0.8rem 1rem;
    gap: 0.75rem;
    /* We change flex-direction back for more control inside */
    flex-direction: row;
    flex-wrap: wrap; /* Allow items to wrap to the next line */
  }

  /* Make main controls (play/seek) centered at the bottom */
  .main-controls-wrapper {
    order: 3; /* This is the magic: send it to the end */
    width: 100%;
    justify-content: center;
    gap: 1.5rem; /* Increase gap between main buttons */
    padding-top: 0.5rem;
  }
  
  .main-controls-wrapper .seek-btn {
    font-size: 1.2rem;
  }
  
  .main-controls-wrapper .play-pause-btn {
      width: 50px;
      height: 50px;
  }
  .main-controls-wrapper .play-pause-btn i {
      font-size: 1.2rem;
  }

  /* This group will now be the main content area */
  .audio-controls-group {
    order: 2; /* It comes before the main controls */
    flex-grow: 1;
    min-width: 0; /* Important for flex-grow to work */
  }

  /* Keep the progress bar and time displays as they were, they fit well */
  .time-and-progress-container {
    gap: 0.5rem;
  }
  .current-time,
  .total-duration {
      min-width: 32px;
      font-size: 0.75rem;
  }

  /* This is the key fix for the volume/title */
  .volume-and-title-container {
    flex-direction: row; /* Put them side-by-side */
    justify-content: space-between; /* Space them out */
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
  }

  .audio-title-wrapper {
    text-align: right; /* Or left if LTR */
  }
  .audio-title {
    font-size: 0.85rem;
  }

  .volume-control {
    gap: 0.4rem;
  }
  
  /* Make the volume slider much smaller on mobile */
  .volume-slider-container {
    width: 65px;
  }
}

.main-controls-wrapper {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.seek-btn {
  background: none;
  border: none;
  color: var(--color-text-secondary);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.5rem;
  border-radius: 50%;
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition-short);
}

.seek-btn:hover {
  color: var(--color-accent);
  background-color: rgba(var(--color-accent-rgb), 0.1);
}

.custom-audio-player-container {
  gap: 0.8rem;
}