html, body {
  min-height: 100vh;
  height: 100%;
  margin: 0;
  padding: 0;
  width: 100vw;
  box-sizing: border-box;
  background: #f5f6fa;
  color: #222;
}
body {
  font-family: 'Segoe UI', Roboto, sans-serif;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  height: 100vh;
  width: 100vw;
}
.header {
  width: 100vw;
  padding: 0 0 14px 0;
  background: transparent;
  text-align: center;
  margin: 0;
  margin-top: 18px;
  font-family: Arial, sans-serif;
  font-size: 2.1rem;
  font-weight: bold;
  letter-spacing: 1.3px;
  color: #222d36;
  text-shadow: 0px 1px 0 #fff8;
  position: relative;
  z-index: 2;
  user-select: none;
}
.steps-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 14px;
  min-height: 82px;
  margin-bottom: 0;
  margin-top: 0;
  background: transparent;
  position: relative;
  z-index: 2;
  flex-wrap: wrap;
  padding-bottom: 12px;
  /* No box-shadow, keep it clean */
}
.step-button {
  border-radius: 9px;
  box-shadow: none;
  border: 2px solid transparent;
  background: #e4e6ea;
  min-width: 100px;
  min-height: 80px;
  max-width: 128px;
  text-align: center;
  cursor: pointer;
  font-size: 1.1rem;
  color: #555;
  transition: border 0.18s, box-shadow 0.13s, background 0.19s, color 0.13s;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 8px 9px 3px 9px;
  user-select: none;
}
.step-button.selected {
  border: 3.2px solid #3888ff;
  background: #3888ff;
  color: #fff;
  font-weight: bold;
  box-shadow: 0 4px 18px #3888ff29;
}
.step-button img {
  width: 54px;
  height: 54px;
  border-radius: 6px;
  margin-bottom: 7px;
  background: #fff;
  border: 2px solid #e0e7ef;
  object-fit: cover;
}
.image-zone {
  flex: 1 1 0;
  width: 100vw;
  height: 0;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #e7eaf0;
  position: relative;
  overflow: hidden;
  margin: 0;
  box-sizing: border-box;
}
.main-image {
  width: 100vw;
  height: 100%;
  max-height: 100%;
  max-width: 100vw;
  object-fit: contain;
  display: block;
  margin: auto;
  border-radius: 0.5vw;
  border: 3.5px solid #e0e7ef;
  background: #fff;
  box-shadow: 0 7px 34px #2a3a5425;
  transition: border 0.2s;
  z-index: 1;
}
@media (max-width: 850px) {
  .header { font-size: 1.2rem; }
  .steps-nav { gap: 7px; }
  .step-button { min-width: 84px; min-height: 58px;}
}
@media (max-width: 600px) {
  .steps-nav { gap: 2vw; }
  .image-zone { background: #e7eaf0; }
  .main-image { border: 1.3px solid #eee;}
}