:root {
    /* font-size: 25px; */
    /* 1rem = 25px */
    --spacing: 1rem;
    --aside-width: 15rem;
    --max-content-width: 60rem;
    /* color */
    --primary-color: #667eea;
    --black: #000;
    --white: #FFF;
    --gray-50: #fafafa;
    --gray-100: #f8f9fa;
    --gray-200: rgba(248, 245, 245, 1);
    --gray-300: rgba(192, 192, 192, 1);
    --gray-400: #ced4da;
    --gray-500: rgba(147, 147, 147, 1);
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    /* Phiên bản cũ */
    --primary-color-hover: #764ba2;
    --primary-gradient: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-color-hover) 100%);
    --secondary-color: rgba(56, 200, 104, 1);
    --background-color: #F2F4F7;
    --text-color-button: #939393;
    --border-color: rgba(226, 226, 226, 1);
    --border-gray: 1px solid rgba(208, 207, 207, 1);
    --border-radius: 0.3rem;
    --border-radius-lg: 25px;
    --border-radius-md: 12px;
    --box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    --box-shadow-hover: 0 12px 35px rgba(102, 126, 234, 0.4);
    --transition: all 0.3s ease;
    --border-button: 1px solid rgba(208, 207, 207, 1);
    --border-dotted: 1px dotted #93939380;
    --controls-gap: 8px;
    --bg-active: #E7F0FF;
    --border-active: 1px solid #8db7ff;
    --track-height: 3px;
    --handle-size: 20px;
    --playhead-size: 20px;
    --timeline-segment-color: #C0C0C0;
  }

  body {
    margin: 0;
    padding: 0;
    font-family: Arial, sans-serif;
    font-size: 1rem;
    line-height: 1.5;
    color: var(--black);
    background-color: var(--gray-200);
  }

  .notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(40, 167, 69, 0.3);
    z-index: 10000;
    font-weight: 600;
    transform: translateX(100%);
    transition: transform 0.3s ease;
  }

  .notification.show {
    transform: translateX(0);
  }

  .notification.hide {
    transform: translateX(100%);
  }
/* 
  html.mtcv-open,
  body.mtcv-open {
    height: 100dvh !important;
    overflow: hidden !important;
    position: fixed;
    width: 100%;
  }

   */