* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", Arial, sans-serif;
  background: #f5f7fb;
  color: #14213d;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  background: #ffffff;
  border-bottom: 1px solid #e6e9f2;
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav {
  max-width: 1120px;
  margin: auto;
  padding: 16px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  font-weight: 800;
  font-size: 22px;
  color: #0b5fff;
}

.nav-links {
  display: flex;
  gap: 18px;
  font-weight: 600;
}

.hero {
  padding: 60px 20px 30px;
  background: linear-gradient(135deg, #e8f0ff, #fff7e6);
}

.hero-content {
  max-width: 880px;
  margin: auto;
  text-align: center;
}

.badge {
  display: inline-block;
  padding: 8px 14px;
  background: #0b5fff;
  color: #ffffff;
  border-radius: 999px;
  font-weight: 700;
}

h1 {
  font-size: clamp(34px, 6vw, 62px);
  line-height: 1;
  margin: 18px 0;
}

.subtitle {
  font-size: 18px;
  color: #475569;
  max-width: 720px;
  margin: 0 auto 28px;
}

.converter-card {
  background: #ffffff;
  border-radius: 26px;
  padding: 24px;
  box-shadow: 0 20px 60px rgba(15, 23, 42, 0.12);
  text-align: left;
}

.upload-box {
  display: flex;
  min-height: 190px;
  border: 2px dashed #9bbcff;
  border-radius: 22px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  cursor: pointer;
  background: #f8fbff;
  transition: 0.25s;
}

.upload-box.dragover {
  border-color: #0b5fff;
  background: #eef5ff;
}

.upload-icon {
  font-size: 44px;
  margin-bottom: 8px;
}

.upload-box input {
  display: none;
}

.settings {
  margin: 20px 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.settings label {
  font-weight: 700;
  color: #334155;
}

.settings select {
  width: 100%;
  margin-top: 8px;
  padding: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 12px;
  font-size: 15px;
}

.primary-btn,
.secondary-btn,
.download-btn {
  border: 0;
  border-radius: 14px;
  padding: 14px 18px;
  font-weight: 800;
  cursor: pointer;
  transition: 0.25s;
}

.primary-btn {
  width: 100%;
  background: #0b5fff;
  color: #ffffff;
  font-size: 17px;
}

.secondary-btn {
  width: 100%;
  margin-top: 10px;
  background: #101828;
  color: #ffffff;
  font-size: 16px;
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.status {
  margin-top: 14px;
  font-weight: 700;
  color: #0f766e;
}

.progress-wrap {
  margin-top: 12px;
  height: 12px;
  background: #e2e8f0;
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  width: 0;
  background: #0b5fff;
  transition: width 0.2s;
}

.hidden {
  display: none;
}

.ad-section {
  max-width: 970px;
  margin: 26px auto;
  padding: 0 20px;
  text-align: center;
}

.ad-label {
  color: #94a3b8;
  font-size: 12px;
  margin-bottom: 6px;
}

.ad-placeholder {
  min-height: 96px;
  border-radius: 18px;
  border: 1px dashed #cbd5e1;
  background: #ffffff;
  display: grid;
  place-items: center;
  color: #94a3b8;
}

.results-section,
.content-section {
  max-width: 1120px;
  margin: auto;
  padding: 34px 20px;
}

.output-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 18px;
}

.image-card {
  background: #ffffff;
  padding: 12px;
  border-radius: 18px;
  box-shadow: 0 8px 28px rgba(15, 23, 42, 0.08);
}

.image-card img {
  width: 100%;
  border-radius: 12px;
  border: 1px solid #e2e8f0;
}

.image-card p {
  font-weight: 800;
  margin: 10px 0;
}

.download-btn {
  width: 100%;
  background: #16a34a;
  color: #ffffff;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin: 18px 0 34px;
}

.steps div {
  background: #ffffff;
  padding: 20px;
  border-radius: 18px;
  box-shadow: 0 8px 28px rgba(15, 23, 42, 0.06);
}

.content-section p {
  color: #475569;
  line-height: 1.7;
}

.footer {
  background: #101828;
  color: #ffffff;
  padding: 24px 20px;
  text-align: center;
}

.footer div {
  margin-top: 10px;
  display: flex;
  gap: 16px;
  justify-content: center;
}

@media (max-width: 720px) {
  .nav {
    flex-direction: column;
    gap: 12px;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
  }

  .settings,
  .steps {
    grid-template-columns: 1fr;
  }
}