:root {
      --bg: #f9fafb;
      --fg: #111827;
      --card: white;
      --accent: #22c55e;
      --accent-dark: #15803d;
      --code: #e5e7eb;
      --error: #dc2626;
    }
    [data-theme="dark"] {
      --bg: #111827;
      --fg: #f9fafb;
      --card: #1f2937;
      --accent: #4ade80;
      --accent-dark: #15803d;
      --code: #374151;
    }

    html, body {
      height: 100%;
      margin: 0;
      padding: 0;
      background: var(--bg);
      color: var(--fg);
      font-family: 'Lato', sans-serif;
      display: flex;
      flex-direction: column;
      transition: all 0.3s ease;
      font-size: 16px;
    }

    body {
      flex-grow: 1;
    }

    header {
      background: var(--accent);
      color: white;
      padding: 1rem;
      text-align: center;
      font-size: 1.5rem;
      position: relative;
      flex-shrink: 0;
      user-select: none;
    }

    .brand {
      font-weight: bold;
    }

    .theme-toggle {
      position: absolute;
      right: 1rem;
      top: 1rem;
      background: transparent;
      border: 2px solid white;
      color: white;
      border-radius: 50%;
      width: 30px;
      height: 30px;
      cursor: pointer;
      transition: transform 0.3s ease;
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
      user-select: none;
    }
    .theme-toggle:hover {
      transform: rotate(180deg);
    }
    .theme-toggle:focus,
    .theme-toggle:active {
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }

    .container {
      padding: 2rem;
      max-width: 800px;
      margin: auto;
      flex-grow: 1;
      overflow-y: auto;
      width: 100%;
      box-sizing: border-box;
    }

    h2.category-title {
      border-left: 4px solid var(--accent);
      padding-left: 0.5rem;
      margin-top: 2rem;
      color: var(--accent-dark);
      user-select: none;
      font-weight: 700;
      font-size: 1.2rem;
    }

    .intro {
      background: var(--card);
      padding: 1rem;
      border-radius: 10px;
      margin: 1rem 0;
      box-shadow: 0 2px 4px rgba(0,0,0,0.1);
      display: flex;
      flex-wrap: wrap;
      user-select: none;
    }

    .intro h2 {
      margin: 0;
      font-size: 1.25rem;
      color: var(--accent-dark);
      user-select: text;
    }

    .intro p {
      margin: 0 0 0.5 0;
      font-size: 1rem;
      color: var(--fg);
      user-select: text;
    }

    .endpoint {
      background: var(--card);
      padding: 1rem;
      border-radius: 10px;
      margin: 1rem 0;
      box-shadow: 0 2px 4px rgba(0,0,0,0.1);
      display: flex;
      justify-content: space-between;
      align-items: center;
      user-select: none;
    }
    .endpoint h3 {
      margin: 0;
      font-size: 1rem;
      user-select: text;
    }
    .endpoint button {
      background: var(--accent);
      color: white;
      border: none;
      padding: 0.4rem 0.8rem;
      border-radius: 6px;
      cursor: pointer;
      font-weight: bold;
      transition: background-color 0.3s ease;
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
      user-select: none;
    }
    .endpoint button:hover {
      background-color: var(--accent-dark);
      box-shadow: none !important;
      outline: none !important;
    }
    .endpoint button:focus,
    .endpoint button:active {
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }
    .endpoint button::-moz-focus-inner {
      border: 0;
    }

    .playground {
      background: var(--card);
      padding: 1rem;
      border-radius: 10px;
      margin-bottom: 1rem;
      box-shadow: 0 1px 3px rgba(0,0,0,0.2);
      display: none;
      animation: fadeIn 0.3s ease forwards;
    }
    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(-10px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .playground select,
    .playground input,
    .playground textarea,
    .playground button {
      width: 100%;
      margin: 0.5rem 0;
      padding: 0.5rem;
      border-radius: 6px;
      border: 1px solid #ccc;
      box-sizing: border-box;
      font-size: 1rem;
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
      user-select: text;
    }
    .playground select:hover,
    .playground input:hover,
    .playground textarea:hover,
    .playground button:hover {
      border-color: var(--accent);
      box-shadow: none !important;
      outline: none !important;
    }
    .playground select:focus,
    .playground input:focus,
    .playground textarea:focus,
    .playground button:focus,
    .playground select:active,
    .playground input:active,
    .playground textarea:active,
    .playground button:active {
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }
    .playground select::-moz-focus-inner,
    .playground input::-moz-focus-inner,
    .playground textarea::-moz-focus-inner,
    .playground button::-moz-focus-inner {
      border: 0;
    }

    .playground textarea {
      min-height: 100px;
      font-family: monospace;
      resize: vertical;
    }
    .playground textarea.invalid {
      border-color: var(--error);
      background: #fee2e2;
    }
    .execute-btn {
      background: var(--accent);
      color: white;
      border: none;
      font-weight: bold;
      cursor: pointer;
      transition: background-color 0.3s ease;
      user-select: none;
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }
    .execute-btn:hover {
      background-color: var(--accent-dark);
      box-shadow: none !important;
      outline: none !important;
    }
    .response-box {
      margin-top: 1rem;
      background: var(--code);
      padding: 1rem;
      border-radius: 6px;
      white-space: pre-wrap;
      font-family: monospace;
      max-height: 300px;
      overflow: auto;
      user-select: text;
    }
    .copy-btn {
      background: transparent;
      border: 1px dashed var(--accent);
      color: var(--accent);
      margin-top: 0.5rem;
      padding: 0.4rem;
      border-radius: 6px;
      cursor: pointer;
      font-size: 0.9rem;
      transition: color 0.3s ease, border-color 0.3s ease;
      user-select: none;
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }
    .copy-btn:hover {
      color: var(--accent-dark);
      border-color: var(--accent-dark);
      box-shadow: none !important;
      outline: none !important;
    }
    .copy-btn:focus,
    .copy-btn:active {
      outline: none !important;
      box-shadow: none !important;
      -webkit-tap-highlight-color: transparent;
    }
    .copy-btn::-moz-focus-inner {
      border: 0;
    }

    .toast {
      position: fixed;
      bottom: 4rem;
      right: 1rem;
      background: var(--accent);
      color: white;
      padding: 0.5rem 1rem;
      border-radius: 6px;
      opacity: 0;
      transition: opacity 0.3s ease;
      pointer-events: none;
      user-select: none;
    }
    .toast.show {
      opacity: 1;
    }

    footer {
      background: var(--card);
      color: gray;
      text-align: center;
      padding: 1rem 0;
      box-shadow: 0 -1px 5px rgba(0,0,0,0.1);
      font-size: 0.9rem;
      user-select: none;
      flex-shrink: 0;
    }