/* Exercise Library Redesigned - Enhanced Mobile & Theme Support */

/* ===== CSS Variables (Enhanced) ===== */
:root {
  /* Primary Colors */
  --primary: #8b5fbf;
  --primary-dark: #6a1b9a;
  --primary-light: #b085db;
  --accent: #ff6b35;
  --accent-light: #ffb85c;
  --accent-dark: #e55a2b;

  /* Dark Theme Colors */
  --background: #0f0f0f;
  --background-secondary: #141414;
  --surface: #1a1a1a;
  --surface-variant: #2d2d2d;
  --surface-elevated: #252525;
  --surface-hover: #333333;
  --on-background: #ffffff;
  --on-surface: #e0e0e0;
  --on-surface-variant: #b0b0b0;
  --on-surface-muted: #888888;
  --border: #3d3d3d;
  --border-light: #4d4d4d;
  --shadow: rgba(0, 0, 0, 0.3);
  --shadow-light: rgba(0, 0, 0, 0.1);

  /* Status Colors */
  --success: #00e676;
  --success-light: #69f0ae;
  --warning: #ffd54f;
  --warning-light: #ffecb3;
  --error: #ff5252;
  --error-light: #ffcdd2;
  --info: #29b6f6;
  --info-light: #81d4fa;

  /* Typography */
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 2.5rem;
  --spacing-3xl: 3rem;
  --spacing-4xl: 4rem;

  /* Border Radius */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-2xl: 32px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.25);

  /* Z-index */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-popover: 600;
  --z-tooltip: 700;
  --z-toast: 800;
}

/* Light Theme */
body:not(.dark-theme) {
  --background: #f8f9fa;
  --background-secondary: #ffffff;
  --surface: #ffffff;
  --surface-variant: #f5f5f5;
  --surface-elevated: #ffffff;
  --surface-hover: #f0f0f0;
  --on-background: #212121;
  --on-surface: #424242;
  --on-surface-variant: #757575;
  --on-surface-muted: #9e9e9e;
  --border: #e0e0e0;
  --border-light: #f0f0f0;
  --shadow: rgba(0, 0, 0, 0.08);
  --shadow-light: rgba(0, 0, 0, 0.04);
}

/* ===== Base Styles ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background-color: var(--background);
  color: var(--on-background);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition), color var(--transition);
  min-height: 100vh;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.hidden {
  display: none !important;
}

/* ===== Header (Enhanced) ===== */
.header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 50%, var(--primary-dark) 100%);
  background-size: 400% 400%;
  animation: gradientShift 8s ease infinite;
  padding: var(--spacing-md) 0;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  backdrop-filter: blur(20px);
  transition: all var(--transition);
}

body:not(.dark-theme) .header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 50%, var(--primary-dark) 100%);
  box-shadow: 0 2px 20px rgba(139, 95, 191, 0.15);
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-lg);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: white;
  font-weight: 700;
  font-size: var(--font-size-xl);
  text-decoration: none;
  transition: transform var(--transition-fast);
}

.logo:hover {
  transform: scale(1.05);
}

.logo-circle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border-radius: 50%;
  font-weight: 800;
  font-size: var(--font-size-lg);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.nav {
  flex: 1;
  max-width: 600px;
}

.nav ul {
  display: flex;
  list-style: none;
  gap: var(--spacing-xs);
  justify-content: center;
}

.nav a {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
  font-weight: 500;
  font-size: var(--font-size-sm);
}

.nav a i {
  font-size: 1.1rem;
}

.nav a span {
  font-weight: 500;
}

.nav a:hover,
.nav a.active {
  color: white;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  transform: translateY(-1px);
}

.nav a.active {
  background: rgba(255, 255, 255, 0.2);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.theme-toggle {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition);
  backdrop-filter: blur(10px);
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.user-profile {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  color: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  cursor: pointer;
  transition: all var(--transition);
}

.user-profile:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-1px);
}

.user-profile .avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  overflow: hidden;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.user-profile img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.user-info {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.user-name {
  font-weight: 600;
  font-size: var(--font-size-sm);
  line-height: 1.2;
}

.user-status {
  font-size: var(--font-size-xs);
  opacity: 0.8;
  line-height: 1;
}

.dropdown-arrow {
  font-size: 1.2rem;
  opacity: 0.7;
  transition: transform var(--transition-fast);
}

.user-profile:hover .dropdown-arrow {
  transform: rotate(180deg);
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition);
  backdrop-filter: blur(10px);
}

.mobile-menu-toggle:hover {
  background: rgba(255, 255, 255, 0.2);
}

.hamburger-line {
  width: 20px;
  height: 2px;
  background: white;
  margin: 2px 0;
  transition: all var(--transition-fast);
  border-radius: 1px;
}

.mobile-menu-toggle.active .hamburger-line:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active .hamburger-line:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

/* ===== Main Content ===== */
.main-content {
  padding: var(--spacing-2xl) 0;
  min-height: calc(100vh - 200px);
}

/* ===== Hero Section (Enhanced) ===== */
.hero-section {
  text-align: center;
  padding: var(--spacing-4xl) 0;
  background: radial-gradient(ellipse at center, rgba(139, 95, 191, 0.1) 0%, transparent 70%);
  position: relative;
  overflow: hidden;
  margin-bottom: var(--spacing-3xl);
}

.hero-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(139,95,191,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
  animation: backgroundMove 20s linear infinite;
  opacity: 0.3;
}

@keyframes backgroundMove {
  0% {
    transform: translate(0, 0);
  }
  100% {
    transform: translate(-10px, -10px);
  }
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
  margin-bottom: var(--spacing-xl);
  box-shadow: var(--shadow-md);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-5px);
  }
}

.hero-content h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  margin-bottom: var(--spacing-lg);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
}

.hero-content p {
  font-size: var(--font-size-xl);
  color: var(--on-surface-variant);
  margin-bottom: var(--spacing-2xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.stat-card {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.stat-icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.stat-info {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.stat-number {
  font-size: var(--font-size-3xl);
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--on-surface-variant);
  font-weight: 500;
  margin-top: var(--spacing-xs);
}

/* ===== Search Section (Enhanced) ===== */
.search-section {
  margin-bottom: var(--spacing-3xl);
}

.search-wrapper {
  display: flex;
  gap: var(--spacing-xl);
  align-items: flex-start;
  max-width: 1200px;
  margin: 0 auto;
}

.search-container {
  flex: 1;
  display: flex;
  gap: var(--spacing-md);
}

.search-box {
  flex: 1;
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: var(--spacing-lg);
  color: var(--on-surface-variant);
  z-index: 2;
  font-size: 1.25rem;
}

.search-box input {
  width: 100%;
  padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-lg) calc(var(--spacing-lg) * 3);
  border: 2px solid var(--border);
  border-radius: var(--radius-full);
  background-color: var(--surface);
  color: var(--on-surface);
  font-size: var(--font-size-base);
  font-weight: 500;
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
}

.search-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(139, 95, 191, 0.1), var(--shadow-md);
  transform: translateY(-2px);
}

.search-box input::placeholder {
  color: var(--on-surface-muted);
}

.search-clear {
  position: absolute;
  right: var(--spacing-lg);
  background: none;
  border: none;
  color: var(--on-surface-variant);
  cursor: pointer;
  opacity: 0;
  transition: all var(--transition-fast);
  padding: var(--spacing-xs);
  border-radius: 50%;
}

.search-clear:hover {
  background: var(--surface-hover);
  color: var(--error);
}

.search-box input:not(:placeholder-shown) + .search-clear {
  opacity: 1;
}

.filter-toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-xl);
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius-full);
  color: var(--on-surface);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  box-shadow: var(--shadow-sm);
  position: relative;
}

.filter-toggle:hover {
  background: var(--surface-variant);
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.filter-count {
  position: absolute;
  top: -8px;
  right: -8px;
  background: var(--accent);
  color: white;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-xs);
  font-weight: 700;
  animation: bounce 0.5s ease;
}

@keyframes bounce {
  0%,
  20%,
  50%,
  80%,
  100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-10px);
  }
  60% {
    transform: translateY(-5px);
  }
}

.ai-chat-toggle {
  flex-shrink: 0;
}

.ai-chat-button {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg) var(--spacing-xl);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  border-radius: var(--radius-full);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.ai-chat-button::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s ease;
}

.ai-chat-button:hover::before {
  left: 100%;
}

.ai-chat-button:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

.ai-icon {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.ai-pulse {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    transform: scale(0.8);
    opacity: 1;
  }
  100% {
    transform: scale(2);
    opacity: 0;
  }
}

.ai-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.ai-title {
  font-weight: 700;
  font-size: var(--font-size-base);
  line-height: 1.2;
}

.ai-subtitle {
  font-size: var(--font-size-xs);
  opacity: 0.9;
  line-height: 1;
}

/* ===== AI Chat Panel (Enhanced) ===== */
.ai-chat-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  margin-bottom: var(--spacing-3xl);
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transition: all var(--transition-slow);
}

.ai-chat-panel.active {
  max-height: 700px;
  opacity: 1;
}

.chat-container {
  height: 100%;
}

.chat-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-xl);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
}

.chat-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.chat-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  backdrop-filter: blur(10px);
  border: 2px solid rgba(255, 255, 255, 0.1);
}

.chat-info h3 {
  margin: 0;
  font-weight: 700;
  font-size: var(--font-size-lg);
}

.online-status {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--font-size-sm);
  opacity: 0.9;
}

.status-dot {
  width: 8px;
  height: 8px;
  background: var(--success);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

.close-chat {
  background: none;
  border: none;
  color: white;
  cursor: pointer;
  font-size: 1.5rem;
  padding: var(--spacing-sm);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.close-chat:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: scale(1.1);
}

.chat-body {
  height: 350px;
  overflow-y: auto;
  padding: var(--spacing-xl);
  background: var(--surface-variant);
  scroll-behavior: smooth;
}

.chat-body::-webkit-scrollbar {
  width: 6px;
}

.chat-body::-webkit-scrollbar-track {
  background: var(--surface);
  border-radius: 3px;
}

.chat-body::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.chat-body::-webkit-scrollbar-thumb:hover {
  background: var(--primary);
}

.chat-message {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-xl);
  animation: slideIn 0.3s ease;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
  font-size: 1.2rem;
}

.message-content {
  flex: 1;
  background: var(--surface);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.message-content p {
  margin: 0;
  line-height: 1.6;
}

.user-message {
  flex-direction: row-reverse;
}

.user-message .message-avatar {
  background: var(--surface-elevated);
  color: var(--on-surface);
  border: 2px solid var(--border);
}

.user-message .message-content {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-color: var(--primary);
}

.quick-questions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.quick-question {
  background: var(--surface-variant);
  border: 1px solid var(--border);
  color: var(--on-surface);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-weight: 500;
}

.quick-question:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  transform: translateY(-2px);
}

.chat-input-container {
  padding: var(--spacing-xl);
  background: var(--surface);
  border-top: 1px solid var(--border);
}

.chat-suggestions {
  margin-bottom: var(--spacing-lg);
}

.suggestion-label {
  font-size: var(--font-size-sm);
  color: var(--on-surface-variant);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  display: block;
}

.suggestions-list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.suggestion {
  background: var(--surface-variant);
  border: 1px solid var(--border);
  color: var(--on-surface);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-weight: 500;
}

.suggestion:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.chat-input-box {
  display: flex;
  gap: var(--spacing-sm);
}

.chat-input-box input {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-variant);
  color: var(--on-surface);
  font-size: var(--font-size-base);
  transition: all var(--transition);
}

.chat-input-box input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(139, 95, 191, 0.1);
}

.send-button {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  border-radius: var(--radius-lg);
  padding: var(--spacing-md) var(--spacing-lg);
  cursor: pointer;
  transition: all var(--transition);
  font-size: 1.2rem;
}

.send-button:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

/* ===== Filter Panel (Enhanced) ===== */
.filter-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  margin-bottom: var(--spacing-3xl);
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transition: all var(--transition-slow);
}

.filter-panel.active {
  max-height: 1000px;
  opacity: 1;
}

.filter-container {
  height: 100%;
}

.filter-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-xl);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
}

.filter-header h3 {
  margin: 0;
  font-weight: 700;
  font-size: var(--font-size-lg);
}

.filter-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.filter-reset {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: white;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-reset:hover {
  background: rgba(255, 255, 255, 0.2);
}

.close-filter {
  background: none;
  border: none;
  color: white;
  cursor: pointer;
  font-size: 1.5rem;
  padding: var(--spacing-sm);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.close-filter:hover {
  background: rgba(255, 255, 255, 0.1);
}

.filter-body {
  padding: var(--spacing-xl);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-2xl);
}

.filter-group h4 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  color: var(--on-surface);
  font-weight: 700;
  font-size: var(--font-size-lg);
  border-bottom: 2px solid var(--primary);
  padding-bottom: var(--spacing-sm);
}

.filter-group h4 i {
  color: var(--primary);
}

.filter-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--spacing-sm);
}

.filter-option {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  cursor: pointer;
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
  border: 1px solid transparent;
}

.filter-option:hover {
  background: var(--surface-variant);
  border-color: var(--border);
}

.filter-option input[type="checkbox"] {
  display: none;
}

.checkmark {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border);
  border-radius: var(--radius-xs);
  position: relative;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.filter-option input[type="checkbox"]:checked + .checkmark {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-color: var(--primary);
}

.filter-option input[type="checkbox"]:checked + .checkmark::after {
  content: "✓";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-weight: bold;
  font-size: 12px;
}

.filter-option span:last-child {
  font-weight: 500;
  color: var(--on-surface);
  text-transform: capitalize;
}

.filter-footer {
  padding: var(--spacing-xl);
  border-top: 1px solid var(--border);
  background: var(--surface-variant);
}

.apply-filters {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-xl);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border: none;
  border-radius: var(--radius-lg);
  color: white;
  font-weight: 700;
  font-size: var(--font-size-base);
  cursor: pointer;
  transition: all var(--transition);
}

.apply-filters:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* ===== Quick Filters (Enhanced) ===== */
.quick-filters {
  margin-bottom: var(--spacing-3xl);
}

.quick-filters-header {
  margin-bottom: var(--spacing-xl);
  text-align: center;
}

.quick-filters-header h3 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--on-surface);
  margin: 0;
}

.quick-filter-scroll {
  display: flex;
  gap: var(--spacing-md);
  overflow-x: auto;
  padding: var(--spacing-md) 0;
  scroll-behavior: smooth;
}

.quick-filter-scroll::-webkit-scrollbar {
  height: 6px;
}

.quick-filter-scroll::-webkit-scrollbar-track {
  background: var(--surface-variant);
  border-radius: 3px;
}

.quick-filter-scroll::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 3px;
}

.quick-filter-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-xl);
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius-xl);
  color: var(--on-surface);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  min-width: 120px;
  white-space: nowrap;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.quick-filter-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(139, 95, 191, 0.1), transparent);
  transition: left 0.5s ease;
}

.quick-filter-btn:hover::before {
  left: 100%;
}

.quick-filter-btn:hover {
  background: var(--surface-variant);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.quick-filter-btn.active {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-color: var(--primary);
  color: white;
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.filter-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--surface-variant);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  transition: all var(--transition);
}

.quick-filter-btn.active .filter-icon {
  background: rgba(255, 255, 255, 0.2);
  color: white;
}

.quick-filter-btn span {
  font-size: var(--font-size-sm);
  font-weight: 600;
}

/* ===== Library Content (Enhanced) ===== */
.library-content {
  margin-bottom: var(--spacing-4xl);
}

.library-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-2xl);
  padding: var(--spacing-xl);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
}

.result-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: var(--spacing-xl);
}

.result-count {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--on-surface);
}

.view-controls {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.view-options {
  display: flex;
  gap: var(--spacing-xs);
  background: var(--surface-variant);
  padding: var(--spacing-xs);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
}

.view-option {
  padding: var(--spacing-sm) var(--spacing-md);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--on-surface-variant);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 1.1rem;
}

.view-option:hover,
.view-option.active {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  transform: scale(1.05);
}

.sort-container {
  position: relative;
}

.sort-select {
  padding: var(--spacing-sm) var(--spacing-lg);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-variant);
  color: var(--on-surface);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='m6 8 4 4 4-4'/%3e%3c/svg%3e");
  background-position: right 0.5rem center;
  background-repeat: no-repeat;
  background-size: 1.5em 1.5em;
  padding-right: 2.5rem;
}

.sort-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(139, 95, 191, 0.1);
}

/* ===== Loading States (Enhanced) ===== */
.loading-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-4xl);
  color: var(--on-surface-variant);
}

.loading-content {
  text-align: center;
  max-width: 400px;
}

.spinner {
  width: 60px;
  height: 60px;
  border: 4px solid var(--surface-variant);
  border-top: 4px solid var(--primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto var(--spacing-lg);
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.loading-content h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--on-surface);
  font-weight: 700;
}

.loading-content p {
  color: var(--on-surface-variant);
  margin: 0;
}

/* ===== Exercise Grid (Enhanced) ===== */
.exercise-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.exercise-grid.list-view {
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
}

.exercise-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  cursor: pointer;
  position: relative;
  height: fit-content;
}

.exercise-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  opacity: 0;
  transition: opacity var(--transition);
  z-index: 1;
}

.exercise-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary);
}

.exercise-card:hover::before {
  opacity: 0.05;
}

.exercise-image-container {
  position: relative;
  height: 240px;
  overflow: hidden;
  z-index: 2;
}

.exercise-image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: linear-gradient(45deg, var(--surface-variant), var(--surface));
  transition: transform var(--transition);
}

.exercise-card:hover .exercise-image {
  transform: scale(1.1);
}

.exercise-card-content {
  padding: var(--spacing-xl);
  position: relative;
  z-index: 2;
}

.exercise-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--on-surface);
  text-transform: capitalize;
  line-height: 1.3;
}

.exercise-meta {
  display: flex;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.exercise-meta-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-sm);
  color: var(--on-surface-variant);
  font-weight: 500;
}

.exercise-meta-item i {
  color: var(--primary);
  font-size: 1.1rem;
}

.exercise-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.exercise-tag {
  padding: var(--spacing-sm) var(--spacing-md);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: capitalize;
}

.exercise-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.action-btn {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface-variant);
  color: var(--on-surface);
  font-size: var(--font-size-sm);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  position: relative;
  overflow: hidden;
}

.action-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transition: left 0.5s ease;
}

.action-btn:hover::before {
  left: 100%;
}

.action-btn:hover {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.favorite-btn.active {
  background: linear-gradient(135deg, var(--error), #ff1744);
  color: white;
  border-color: var(--error);
}

.favorite-btn.active:hover {
  background: linear-gradient(135deg, #d50000, var(--error));
}

/* ===== Empty State (Enhanced) ===== */
.empty-state {
  padding: var(--spacing-4xl);
}

.empty-content {
  text-align: center;
  max-width: 500px;
  margin: 0 auto;
}

.empty-icon {
  width: 120px;
  height: 120px;
  margin: 0 auto var(--spacing-xl);
  background: var(--surface-variant);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--on-surface-variant);
}

.empty-icon i {
  font-size: 3rem;
}

.empty-content h3 {
  margin-bottom: var(--spacing-md);
  color: var(--on-surface);
  font-size: var(--font-size-2xl);
  font-weight: 700;
}

.empty-content p {
  color: var(--on-surface-variant);
  margin-bottom: var(--spacing-xl);
  font-size: var(--font-size-lg);
}

/* ===== Load More (Enhanced) ===== */
.load-more-container {
  text-align: center;
  margin: var(--spacing-2xl) 0;
}

.load-more-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-2xl);
  background: var(--surface);
  color: var(--on-surface);
  border: 2px solid var(--border);
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: var(--font-size-base);
  cursor: pointer;
  transition: all var(--transition);
  box-shadow: var(--shadow-sm);
}

.load-more-btn:hover {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-color: var(--primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.load-more-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* ===== Footer (Enhanced) ===== */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  margin-top: var(--spacing-4xl);
  transition: all var(--transition);
}

body:not(.dark-theme) .footer {
  background: var(--surface-variant);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-2xl);
  padding: var(--spacing-4xl) 0 var(--spacing-2xl);
}

.footer-section h4 {
  color: var(--on-surface);
  font-weight: 700;
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-lg);
}

.footer-section p {
  color: var(--on-surface-variant);
  margin-bottom: var(--spacing-lg);
  line-height: 1.6;
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: var(--spacing-sm);
}

.footer-section ul li a {
  color: var(--on-surface-variant);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-section ul li a:hover {
  color: var(--primary);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
}

.footer-logo .logo-circle {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: var(--font-size-lg);
}

.footer-logo span {
  font-weight: 700;
  font-size: var(--font-size-xl);
  color: var(--on-surface);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
}

.social-link {
  width: 44px;
  height: 44px;
  background: var(--surface-variant);
  border: 1px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--on-surface-variant);
  text-decoration: none;
  transition: all var(--transition);
}

.social-link:hover {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-color: var(--primary);
  transform: translateY(-2px);
}

.newsletter {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.newsletter input {
  flex: 1;
  padding: var(--spacing-md);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-variant);
  color: var(--on-surface);
  transition: all var(--transition);
}

.newsletter input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(139, 95, 191, 0.1);
}

.newsletter-btn {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: var(--spacing-md);
  cursor: pointer;
  transition: all var(--transition);
}

.newsletter-btn:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-xl) 0;
  border-top: 1px solid var(--border);
  color: var(--on-surface-variant);
}

.footer-links {
  display: flex;
  gap: var(--spacing-lg);
}

.footer-links a {
  color: var(--on-surface-variant);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary);
}

/* ===== Modal (Enhanced) ===== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
}

.modal.active {
  opacity: 1;
  visibility: visible;
}

.modal-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(4px);
  z-index: var(--z-modal-backdrop);
}

.modal-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 900px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  transform: scale(0.9);
  transition: transform var(--transition);
  z-index: var(--z-modal);
  position: relative;
}

.modal.active .modal-content {
  transform: scale(1);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-xl);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
}

.modal-header h2 {
  margin: 0;
  font-weight: 700;
  font-size: var(--font-size-2xl);
  text-transform: capitalize;
}

.close-modal {
  background: none;
  border: none;
  color: white;
  cursor: pointer;
  font-size: 1.5rem;
  padding: var(--spacing-sm);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.close-modal:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: scale(1.1);
}

.modal-body {
  padding: var(--spacing-2xl);
}

.exercise-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-2xl);
}

.media-container {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  background: var(--surface-variant);
}

.media-container img {
  width: 100%;
  height: auto;
  display: block;
}

.info-badges {
  display: grid;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-2xl);
}

.detail-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: var(--surface-variant);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}

.detail-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.detail-content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.detail-label {
  font-weight: 600;
  color: var(--on-surface-variant);
  font-size: var(--font-size-sm);
}

.detail-value {
  font-weight: 700;
  color: var(--on-surface);
  text-transform: capitalize;
  font-size: var(--font-size-base);
}

.exercise-instructions h3 {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  color: var(--on-surface);
  font-weight: 700;
  font-size: var(--font-size-xl);
}

.exercise-instructions h3 i {
  color: var(--primary);
}

.exercise-instructions ol {
  padding-left: var(--spacing-xl);
  color: var(--on-surface-variant);
}

.exercise-instructions li {
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
  font-size: var(--font-size-base);
}

.modal-footer {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-xl);
  border-top: 1px solid var(--border);
  background: var(--surface-variant);
}

.btn-primary,
.btn-secondary {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg) var(--spacing-xl);
  border-radius: var(--radius-lg);
  font-weight: 700;
  font-size: var(--font-size-base);
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--surface);
  color: var(--on-surface);
  border: 2px solid var(--border);
}

.btn-secondary:hover {
  background: var(--surface-variant);
  border-color: var(--primary);
  transform: translateY(-2px);
}

/* ===== Toast (Enhanced) ===== */
.toast {
  position: fixed;
  top: 24px;
  right: 24px;
  background: var(--surface);
  color: var(--on-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  z-index: var(--z-toast);
  transform: translateX(100%);
  transition: transform var(--transition);
  max-width: 420px;
  min-width: 300px;
  backdrop-filter: blur(10px);
}

.toast:not(.hidden) {
  transform: translateX(0);
}

.toast-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-lg);
  flex: 1;
}

.toast.success {
  border-color: var(--success);
}

.toast.success .toast-content i {
  color: var(--success);
}

.toast.error {
  border-color: var(--error);
}

.toast.error .toast-content i {
  color: var(--error);
}

.toast.warning {
  border-color: var(--warning);
}

.toast.warning .toast-content i {
  color: var(--warning);
}

.toast.info {
  border-color: var(--info);
}

.toast.info .toast-content i {
  color: var(--info);
}

.toast-close {
  background: none;
  border: none;
  color: var(--on-surface-variant);
  cursor: pointer;
  padding: var(--spacing-md);
  border-radius: 50%;
  transition: all var(--transition-fast);
}

.toast-close:hover {
  background: var(--surface-hover);
  color: var(--error);
}

/* ===== Responsive Design (Enhanced) ===== */
@media (max-width: 1024px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .search-wrapper {
    flex-direction: column;
    gap: var(--spacing-lg);
  }

  .exercise-grid {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-lg);
  }

  .exercise-detail-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
}

@media (max-width: 768px) {
  .header .container {
    gap: var(--spacing-md);
  }

  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: var(--z-dropdown);
  }

  .nav.active {
    display: block;
  }

  .nav ul {
    flex-direction: column;
    padding: var(--spacing-lg);
    gap: var(--spacing-sm);
  }

  .nav a {
    color: var(--on-surface);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
  }

  .nav a:hover,
  .nav a.active {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
  }

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

  .user-info {
    display: none;
  }

  .hero-content h1 {
    font-size: clamp(2rem, 8vw, 3rem);
  }

  .hero-content p {
    font-size: var(--font-size-base);
  }

  .search-container {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .ai-text {
    display: none;
  }

  .filter-body {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .library-header {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-lg);
  }

  .result-info {
    flex-direction: column;
    align-items: stretch;
    gap: var(--spacing-md);
  }

  .view-controls {
    justify-content: space-between;
  }

  .exercise-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .exercise-actions {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .modal-content {
    width: 95%;
    margin: var(--spacing-md);
  }

  .modal-footer {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
    text-align: center;
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--spacing-md);
    text-align: center;
  }

  .toast {
    right: var(--spacing-md);
    left: var(--spacing-md);
    max-width: none;
    min-width: auto;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }

  .header {
    padding: var(--spacing-sm) 0;
  }

  .logo {
    font-size: var(--font-size-lg);
  }

  .logo-circle {
    width: 36px;
    height: 36px;
    font-size: var(--font-size-base);
  }

  .theme-toggle,
  .mobile-menu-toggle {
    width: 36px;
    height: 36px;
  }

  .user-profile .avatar {
    width: 32px;
    height: 32px;
  }

  .hero-section {
    padding: var(--spacing-2xl) 0;
  }

  .hero-content h1 {
    font-size: clamp(1.75rem, 6vw, 2.5rem);
  }

  .stat-card {
    padding: var(--spacing-lg);
  }

  .stat-icon {
    width: 48px;
    height: 48px;
    font-size: 1.25rem;
  }

  .quick-filter-btn {
    min-width: 100px;
    padding: var(--spacing-md) var(--spacing-lg);
  }

  .filter-icon {
    width: 40px;
    height: 40px;
    font-size: 1.25rem;
  }

  .quick-filter-btn span {
    font-size: var(--font-size-xs);
  }

  .exercise-card-content {
    padding: var(--spacing-lg);
  }

  .exercise-title {
    font-size: var(--font-size-lg);
  }

  .modal-body {
    padding: var(--spacing-lg);
  }

  .chat-body {
    height: 280px;
  }

  .ai-chat-panel.active {
    max-height: 600px;
  }
}

/* ===== Animations & Interactions ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease forwards;
}

.animate-slide-in-right {
  animation: slideInRight 0.4s ease forwards;
}

.animate-scale-in {
  animation: scaleIn 0.3s ease forwards;
}

/* ===== Focus States & Accessibility ===== */
*:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

button:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ===== Print Styles ===== */
@media print {
  .header,
  .footer,
  .ai-chat-panel,
  .filter-panel,
  .toast,
  .modal {
    display: none !important;
  }

  .main-content {
    padding: 0;
  }

  .exercise-card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ccc;
  }
}

/* ===== High Contrast Mode ===== */
@media (prefers-contrast: high) {
  :root {
    --border: #000000;
    --shadow: rgba(0, 0, 0, 0.5);
  }

  body:not(.dark-theme) {
    --border: #000000;
    --on-surface-variant: #000000;
  }
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .hero-section::before {
    animation: none;
  }

  .ai-pulse,
  .status-dot {
    animation: none;
  }
}