@import url('https://fonts.googleapis.com/css2?family=PT+Sans:wght@400;700&display=swap');

:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #111115;
  --bg-tertiary: #16161d;
  --bg-hover: #1c1c24;
  --text-primary: #e8e8f0;
  --text-secondary: #a0a0b0;
  --text-muted: #6a6a7a;
  --accent-primary: #a855f7;
  --accent-hover: #9333ea;
  --accent-success: #22c55e;
  --border-color: #2a2a30;
  --shadow-sm: 0 2px 5px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.2);
  --sidebar-width: 270px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'PT Sans', sans-serif;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  overflow-y: auto;
  z-index: 100;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
}

.sidebar-header {
  padding: 20px 16px 14px;
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.sidebar-logo {
  width: 40px;
  height: 40px;
  margin-bottom: 10px;
  cursor: pointer;
}

.sidebar-header h3 {
  color: var(--text-primary);
  font-size: 16px;
  font-weight: 700;
}

.sidebar-header p {
  color: var(--text-muted);
  font-size: 12px;
  margin-top: 4px;
}

.sidebar-items {
  flex: 1;
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 10px 12px;
  background: transparent;
  border: none;
  border-radius: 10px;
  color: var(--text-secondary);
  font-size: 13px;
  cursor: pointer;
  transition: all 0.15s;
  text-align: left;
  font-weight: 500;
}

.sidebar-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.sidebar-item.active {
  background: var(--accent-primary);
  color: white;
}

.sidebar-item i {
  width: 20px;
  font-size: 14px;
}

.app {
  margin-left: var(--sidebar-width);
  padding: 20px 20px 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  text-align: center;
  margin-bottom: 24px;
}

.logo-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  cursor: pointer;
}

.logo-icon {
  width: 28px;
  height: 28px;
}

.header h1 {
  font-size: 26px;
  font-weight: 700;
  color: var(--accent-primary);
}

.logo-highlight {
  color: var(--text-primary);
  font-weight: 400;
}

.header p {
  color: var(--text-secondary);
  font-size: 14px;
  margin-top: 6px;
}

.back-link-wrapper {
  margin-bottom: 14px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 30px;
  color: var(--accent-primary);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  transition: all 0.15s;
}

.back-link:hover {
  background: var(--bg-hover);
  border-color: var(--accent-primary);
}

.search-container {
  margin-bottom: 24px;
}

.search-wrapper {
  position: relative;
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 15px;
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 12px 14px 12px 40px;
  font-size: 15px;
  border: 1.5px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  outline: none;
  transition: all 0.15s;
}

.search-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(168, 85, 247, 0.15);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-clear {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
}

.search-clear:hover {
  background: var(--bg-hover);
  color: var(--text-secondary);
}

.main {
  flex: 1;
}

.container {
  width: 100%;
}

.section-container {
  margin-bottom: 20px;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--accent-primary);
}

.section-header i {
  font-size: 20px;
  color: var(--accent-primary);
}

.section-header h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.section-description {
  color: var(--text-secondary);
  margin-bottom: 14px;
  font-size: 13px;
}

.goto-beginner-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: rgba(168, 85, 247, 0.1);
  border: 1.5px solid var(--accent-primary);
  border-radius: 12px;
  color: var(--text-primary);
  text-decoration: none;
  transition: all 0.15s;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 2.5rem;
}

.goto-beginner-btn:hover {
  background: var(--accent-primary);
  color: white;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(168, 85, 247, 0.25);
}

.goto-beginner-btn span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.goto-beginner-btn i:last-child {
  color: var(--accent-primary);
  transition: transform 0.2s;
}

.goto-beginner-btn:hover i:last-child {
  color: white;
  transform: translateX(4px);
}

.no-results {
  text-align: center;
  padding: 40px 20px;
  background: var(--bg-secondary);
  border-radius: 14px;
  border: 1px solid var(--border-color);
}

.no-results i {
  font-size: 40px;
  color: var(--text-muted);
  margin-bottom: 14px;
  opacity: 0.5;
}

.no-results p {
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--bg-tertiary);
  border: 1.5px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
}

.btn:hover {
  background: var(--bg-hover);
  border-color: var(--accent-primary);
}

.btn-primary {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.footer {
  text-align: center;
  padding-top: 24px;
  margin-top: 24px;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 12px;
}

.footer a {
  color: var(--accent-primary);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

.footer-note {
  margin-top: 6px;
  font-size: 11px;
}

.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  left: auto;
  transform: translateX(400px);
  background: var(--bg-secondary);
  color: var(--text-primary);
  padding: 12px 20px;
  border-radius: 7.5px;
  font-size: 14px;
  font-weight: 500;
  z-index: 3000;
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  white-space: nowrap;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  border-left: 2px solid var(--accent-success);
  display: flex;
  align-items: center;
  gap: 8px;
}

.toast.show {
  transform: translateX(0);
  opacity: 1;
}

::-webkit-scrollbar {
  width: 3px;
  height: 3px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--accent-primary);
  border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-hover);
}

.hidden {
  display: none !important;
}

.hamburger-btn {
  display: none;
  position: fixed;
  top: 14px;
  left: 14px;
  z-index: 1001;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: var(--bg-secondary);
  border: 1.5px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  padding: 0;
  box-shadow: var(--shadow-md);
}

.hamburger-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  margin: 3px 0;
  transition: all 0.3s ease;
  border-radius: 2px;
}

.hamburger-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger-btn.active span:nth-child(2) {
  opacity: 0;
  transform: translateX(-10px);
}

.hamburger-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

.menu-overlay {
  display: none;
  position: fixed;
  top: 0; left: 0;
  right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 1999;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  backdrop-filter: blur(4px);
}

.menu-overlay.active {
  opacity: 1;
  visibility: visible;
}

.menu-panel {
  display: none;
  position: fixed;
  top: 0;
  left: -280px;
  width: 240px;
  height: 100vh;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border-color);
  z-index: 2000;
  transition: left 0.3s ease;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.menu-panel.open {
  left: 0;
}

.menu-header {
  padding: 1rem;
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.menu-logo {
  width: 40px;
  height: 40px;
}

.menu-header h3 {
  color: var(--text-primary);
  font-size: 20px;
  font-weight: 700;
}

.menu-header p {
  color: var(--text-muted);
  font-size: 12px;
}

.menu-items {
  padding: 12px 10px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.menu-item {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 0 1rem;
  background: transparent;
  border: none;
  border-radius: 10px;
  color: var(--text-secondary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.15s;
  text-align: left;
  font-weight: 500;
}

.menu-item:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.menu-item.active {
  background: var(--accent-primary);
  color: white;
}

.menu-item i {
  width: 22px;
  font-size: 14px;
}

.mobile-back-link {
  display: inline-block;
  color: var(--accent-primary);
  text-decoration: none;
  font-size: 13px;
  margin-top: 10px;
  font-weight: 500;
}

.mobile-back-link:hover {
  text-decoration: underline;
}