.tinkercad-organizer {
  --navy: #17324d;
  --blue: #147d92;
  --orange: #f26b38;
  --yellow: #fff3c4;
  --light: #f4f8fa;
  --line: #cbd9df;
  max-width: 1050px;
  margin: 0 auto;
  color: #243746;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 17px;
  line-height: 1.7;
}
.tinkercad-organizer * { box-sizing: border-box; }
.tinkercad-organizer h1,
.tinkercad-organizer h2,
.tinkercad-organizer h3 { color: var(--navy); line-height: 1.25; }
.tinkercad-organizer h1 { margin-bottom: 12px; font-size: clamp(2rem, 5vw, 3.4rem); }
.tinkercad-organizer h2 { margin-top: 42px; padding-bottom: 9px; border-bottom: 3px solid var(--orange); font-size: clamp(1.5rem, 3vw, 2rem); }
.tinkercad-organizer h3 { margin-top: 0; font-size: 1.25rem; }
.tinkercad-organizer a { color: #086e7e; font-weight: 700; text-underline-offset: 3px; }
.tinkercad-organizer .lesson-header { padding: clamp(24px, 6vw, 58px); border-radius: 24px; background: linear-gradient(135deg, #17324d, #126f83); color: #fff; }
.tinkercad-organizer .lesson-header h1,
.tinkercad-organizer .lesson-header p { color: #fff; }
.tinkercad-organizer .lesson-label { display: inline-block; margin: 0; padding: 6px 12px; border: 1px solid rgba(255,255,255,.35); border-radius: 999px; font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
.tinkercad-organizer .video { position: relative; height: 0; margin-top: 24px; padding-bottom: 56.25%; overflow: hidden; border-radius: 16px; background: #000; }
.tinkercad-organizer .video iframe { position: absolute; inset: 0; width: 100%; height: 100%; }
.tinkercad-organizer .intro,
.tinkercad-organizer .step,
.tinkercad-organizer .login-box,
.tinkercad-organizer .summary { margin-top: 22px; padding: clamp(20px, 4vw, 30px); border-radius: 16px; }
.tinkercad-organizer .intro,
.tinkercad-organizer .step { border: 1px solid var(--line); background: #fff; }
.tinkercad-organizer .step { border-left: 6px solid var(--blue); box-shadow: 0 8px 24px rgba(23,50,77,.07); }
.tinkercad-organizer .step-number { display: inline-block; margin-bottom: 10px; color: var(--orange); font-size: .85rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.tinkercad-organizer .table-wrap { overflow-x: auto; margin: 24px 0; border: 1px solid var(--line); border-radius: 13px; }
.tinkercad-organizer table { width: 100%; min-width: 580px; border-collapse: collapse; background: #fff; }
.tinkercad-organizer th,
.tinkercad-organizer td { padding: 13px 16px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); text-align: left; }
.tinkercad-organizer th { background: var(--navy); color: #fff; }
.tinkercad-organizer kbd { display: inline-block; padding: 3px 8px; border: 1px solid #9aa9b2; border-bottom-width: 3px; border-radius: 6px; background: #fff; color: #172b3a; font: 700 .9em Arial, Helvetica, sans-serif; white-space: nowrap; }
.tinkercad-organizer .important { margin: 18px 0; padding: 16px 18px; border-left: 5px solid var(--orange); border-radius: 0 12px 12px 0; background: #fff2e9; }
.tinkercad-organizer .login-box { border: 2px solid #d49c00; background: var(--yellow); }
.tinkercad-organizer .login-box h2 { margin-top: 0; border-bottom-color: #d49c00; }
.tinkercad-organizer .login-name { display: inline-block; padding: 5px 10px; border: 1px dashed #9d7300; border-radius: 7px; background: #fff; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-weight: 800; }
.tinkercad-organizer details { margin: 12px 0; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.tinkercad-organizer summary { padding: 15px 18px; color: var(--navy); cursor: pointer; font-weight: 800; }
.tinkercad-organizer details p { margin: 0; padding: 0 18px 18px; }
.tinkercad-organizer .summary { border-left: 6px solid var(--orange); background: var(--light); font-size: 1.05rem; }
@media (max-width: 650px) {
  .tinkercad-organizer { font-size: 16px; }
  .tinkercad-organizer .lesson-header { border-radius: 16px; }
}