:root {
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #101828;
  --muted: #5f6b7a;
  --border: #d9e2ef;
  --primary: #155eef;
  --primary-dark: #004eeb;
  --primary-soft: #eaf1ff;
  --ok-bg: #ecfdf3;
  --ok: #067647;
  --warn-bg: #fff7ed;
  --warn: #b54708;
  --shadow: 0 18px 50px rgba(15, 23, 42, .08);
  --radius: 24px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(21, 94, 239, .12), transparent 32rem),
    linear-gradient(180deg, #ffffff 0%, var(--bg) 42%);
  line-height: 1.58;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border);
  background: rgba(255,255,255,.88);
  backdrop-filter: blur(12px);
}
.nav {
  max-width: 1120px;
  margin: 0 auto;
  padding: 16px 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.logo {
  color: var(--text);
  font-weight: 900;
  letter-spacing: -0.8px;
  font-size: 1.35rem;
}
.logo span { color: var(--primary); }
.nav-links {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: flex-end;
  font-size: .96rem;
}
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 34px 18px;
}
.hero {
  padding: 30px 0 28px;
  text-align: center;
}
.hero h1 {
  max-width: 920px;
  margin: 0 auto 14px;
  font-size: clamp(2.25rem, 5vw, 4.8rem);
  line-height: 1.02;
  letter-spacing: -2.4px;
}
.hero p {
  max-width: 780px;
  margin: 0 auto;
  color: var(--muted);
  font-size: 1.12rem;
}
.badges {
  margin-top: 20px;
  display: flex;
  gap: 9px;
  flex-wrap: wrap;
  justify-content: center;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--border);
  background: #fff;
  color: #445064;
  padding: 8px 12px;
  border-radius: 999px;
  font-size: .93rem;
}
.card {
  background: rgba(255,255,255,.96);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.home-grid {
  max-width: 1000px;
  margin: 8px auto 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.tool-link {
  padding: 20px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 22px;
  box-shadow: 0 8px 25px rgba(15, 23, 42, .045);
  color: var(--text);
}
.tool-link:hover { text-decoration: none; transform: translateY(-2px); transition: .16s ease; }
.tool-link h2, .tool-link h3 {
  margin: 0 0 8px;
  color: var(--primary);
  font-size: 1.22rem;
}
.tool-link p { margin: 0; color: var(--muted); }
.tool-card {
  max-width: 920px;
  margin: 0 auto;
  padding: 24px;
}
.upload-box {
  border: 2px dashed #b7c4d8;
  border-radius: 22px;
  background: linear-gradient(180deg, #ffffff 0%, #f8fbff 100%);
  text-align: center;
  padding: 30px 18px;
  transition: .18s ease;
}
.upload-box.dragover { border-color: var(--primary); background: var(--primary-soft); }
.upload-box input { display: none; }
.upload-title { margin: 0 0 8px; font-size: 1.25rem; font-weight: 900; }
.upload-hint { color: var(--muted); margin: 0 0 18px; }
.upload-btn, button, .download-btn {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  background: var(--primary);
  color: white;
  padding: 13px 18px;
  cursor: pointer;
  font-weight: 900;
  font-size: 1rem;
}
.upload-btn:hover, button:hover, .download-btn:hover {
  background: var(--primary-dark);
  color: white;
  text-decoration: none;
}
button.secondary { background: #eef4ff; color: #123b7a; }
button.secondary:hover { background: #dce9ff; color: #123b7a; }
button:disabled { opacity: .58; cursor: not-allowed; }
.tool-options {
  margin: 20px 0 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.field { display: flex; flex-direction: column; gap: 8px; }
.field label { font-weight: 900; }
select, input[type="number"] {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 11px 13px;
  font-size: 1rem;
  outline: none;
  background: #fbfdff;
  color: var(--text);
}
select:focus, input[type="number"]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(21, 94, 239, .12);
}
.actions {
  margin-top: 18px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}
.result, .warning {
  margin-top: 16px;
  border-radius: 18px;
  padding: 14px 15px;
  display: none;
  font-weight: 800;
}
.result { color: var(--ok); background: var(--ok-bg); }
.warning { color: var(--warn); background: var(--warn-bg); }
.preview-grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.preview {
  border: 1px solid var(--border);
  background: #fbfdff;
  border-radius: 20px;
  padding: 14px;
  min-height: 220px;
}
.preview h3 { margin: 0 0 8px; font-size: 1rem; }
.preview img {
  width: 100%;
  height: 300px;
  object-fit: contain;
  border-radius: 14px;
  background: #eef2f7;
  display: block;
}
.info { color: var(--muted); font-size: .94rem; margin: 8px 0 0; }
.content {
  max-width: 920px;
  margin: 28px auto 0;
  padding: 26px;
}
.content h2 { margin-top: 0; letter-spacing: -0.6px; font-size: 1.75rem; }
.content h3 { margin-top: 26px; }
.content p, .content li { color: #344054; }
.steps {
  counter-reset: step;
  display: grid;
  gap: 12px;
  padding: 0;
  margin: 18px 0 0;
}
.steps li {
  list-style: none;
  border: 1px solid var(--border);
  background: #fbfdff;
  border-radius: 18px;
  padding: 14px 14px 14px 52px;
  position: relative;
}
.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 14px;
  top: 14px;
  width: 26px;
  height: 26px;
  border-radius: 999px;
  background: var(--primary);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 900;
}
.related {
  max-width: 920px;
  margin: 18px auto 0;
  padding: 22px;
}
.related h2 { margin-top: 0; }
.related-links { display: flex; flex-wrap: wrap; gap: 9px; }
.related-links a {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  padding: 9px 12px;
}
footer {
  padding: 34px 18px 44px;
  text-align: center;
  color: var(--muted);
  font-size: .94rem;
}
footer a { color: #445064; }
@media (max-width: 860px) {
  .nav { align-items: flex-start; flex-direction: column; }
  .nav-links { justify-content: flex-start; gap: 10px; }
  .hero { text-align: left; }
  .badges { justify-content: flex-start; }
  .tool-options, .preview-grid, .home-grid { grid-template-columns: 1fr; }
  .preview img { height: 230px; }
  .tool-card, .content, .related { padding: 18px; }
}