* { box-sizing: border-box; }

:root {
  --slate-950: #172033;
  --slate-900: #243044;
  --slate-800: #334155;
  --slate-700: #475569;
  --slate-500: #64748b;
  --slate-300: #cbd5e1;
  --slate-200: #e2e8f0;
  --slate-100: #f1f5f9;
  --slate-50: #f8fafc;
  --white: #ffffff;
  --gold: #c8a76c;
  --green: #2f855a;
}

html, body { min-height: 100%; }

body {
  margin: 0;
  background: #eef2f6;
  color: var(--slate-950);
  font-family: Arial, Helvetica, sans-serif;
}

.app-shell {
  width: min(1220px, calc(100% - 32px));
  margin: 20px auto;
  background: var(--white);
  border: 1px solid var(--slate-200);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 12px 34px rgba(15, 23, 42, .10);
}

.topbar {
  min-height: 94px;
  padding: 12px 26px;
  display: grid;
  grid-template-columns: 72px 1fr 72px;
  align-items: center;
  gap: 22px;
  background: var(--white);
  border-bottom: 1px solid var(--slate-200);
}

.topbar h1 {
  margin: 0;
  text-align: center;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--slate-900);
}

.header-logo {
  width: 68px;
  height: 68px;
  border-radius: 50%;
  object-fit: cover;
  display: block;
  border: 1px solid var(--slate-200);
  background: white;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(380px, .95fr);
  gap: 22px;
  padding: 22px;
  background: var(--slate-50);
}

.panel {
  background: var(--white);
  border: 1px solid var(--slate-200);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 5px 16px rgba(15, 23, 42, .05);
}

.panel-title {
  padding: 12px 18px;
  background: var(--slate-800);
  color: var(--white);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 20px;
  font-weight: 700;
}

.panel-body { padding: 20px; }

label {
  display: block;
  margin-bottom: 7px;
  color: var(--slate-800);
  font-size: 14px;
  font-weight: 700;
}

.input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

input[type="url"] {
  width: 100%;
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--slate-300);
  border-radius: 7px;
  color: var(--slate-950);
  font-size: 16px;
  outline: none;
}

input[type="url"]:focus {
  border-color: var(--slate-700);
  box-shadow: 0 0 0 3px rgba(71, 85, 105, .12);
}

.status {
  min-height: 21px;
  margin-top: 7px;
  color: var(--slate-500);
  font-size: 13px;
}

.status.valid { color: var(--green); }
.status.invalid { color: #a33a3a; }

h2 {
  margin: 0 0 12px;
  color: var(--slate-800);
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: .055em;
}

.section-divider {
  height: 1px;
  margin: 19px 0;
  background: var(--slate-200);
}

.style-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.style-card {
  min-height: 78px;
  padding: 10px 7px;
  border: 1px solid var(--slate-300);
  border-radius: 8px;
  background: var(--white);
  color: var(--slate-800);
  cursor: pointer;
  font-weight: 700;
}

.style-card:hover { background: var(--slate-50); }

.style-card.selected {
  border-color: var(--slate-800);
  box-shadow: inset 0 0 0 1px var(--slate-800);
  background: var(--slate-100);
}

.style-swatch {
  width: 34px;
  height: 34px;
  margin: 0 auto 7px;
  display: block;
  background-color: var(--slate-800);
}

.swatch-square { border-radius: 0; }
.swatch-rounded { border-radius: 8px; }
.swatch-dots { border-radius: 50%; transform: scale(.82); }
.swatch-extra { border-radius: 12px; }
.swatch-classy { clip-path: polygon(0 0, 100% 0, 100% 45%, 45% 100%, 0 100%); }
.swatch-classy-rounded { border-radius: 13px 2px 13px 2px; transform: rotate(4deg); }

.appearance-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.color-control {
  min-height: 44px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 6px 10px;
  border: 1px solid var(--slate-300);
  border-radius: 7px;
}

input[type="color"] {
  width: 34px;
  height: 30px;
  padding: 0;
  border: none;
  background: transparent;
  cursor: pointer;
}

.color-control span {
  color: var(--slate-700);
  font-family: Consolas, Monaco, monospace;
  font-size: 13px;
}

.quiet-note {
  margin: 13px 0 0;
  color: var(--slate-500);
  font-size: 13px;
  line-height: 1.45;
}

.primary-btn, .secondary-btn {
  min-height: 44px;
  border-radius: 7px;
  padding: 10px 18px;
  font-weight: 700;
  font-size: 14px;
  cursor: pointer;
}

.primary-btn {
  border: 1px solid var(--slate-800);
  background: var(--slate-800);
  color: var(--white);
}

.primary-btn:hover { background: var(--slate-900); }

.secondary-btn {
  border: 1px solid var(--slate-400, #94a3b8);
  background: var(--white);
  color: var(--slate-800);
}

.secondary-btn:hover { background: var(--slate-50); }

.actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.wide { width: 100%; }

.preview-body { text-align: center; }

.preview-intro {
  margin: 0 0 15px;
  color: var(--slate-500);
  font-size: 14px;
}

.qr-stage {
  min-height: 438px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 13px;
  border: 1px solid var(--slate-200);
  border-radius: 9px;
  background:
    linear-gradient(45deg, #f4f6f8 25%, transparent 25%),
    linear-gradient(-45deg, #f4f6f8 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #f4f6f8 75%),
    linear-gradient(-45deg, transparent 75%, #f4f6f8 75%);
  background-size: 18px 18px;
  background-position: 0 0, 0 9px, 9px -9px, -9px 0px;
}

.qr-mount {
  line-height: 0;
  filter: drop-shadow(0 5px 10px rgba(15, 23, 42, .12));
}

.qr-mount canvas, .qr-mount svg { display: block; }

.about-box {
  margin-top: 16px;
  padding: 14px 16px;
  text-align: left;
  border-radius: 8px;
  background: var(--slate-100);
  color: var(--slate-700);
  font-size: 13px;
  line-height: 1.45;
}

.about-box strong {
  color: var(--slate-800);
  text-transform: uppercase;
  letter-spacing: .04em;
}

.about-box p { margin: 6px 0 0; }

footer {
  min-height: 54px;
  padding: 15px 22px;
  display: flex;
  align-items: center;
  gap: 10px;
  border-top: 1px solid var(--slate-200);
  background: var(--white);
  color: var(--slate-500);
  font-size: 12px;
}

.version { margin-left: auto; }
.footer-divider { color: var(--slate-300); }

@media (max-width: 900px) {
  .workspace { grid-template-columns: 1fr; }
  .preview-panel { min-width: 0; }
}

@media (max-width: 600px) {
  .app-shell { width: 100%; margin: 0; border-radius: 0; border-left: 0; border-right: 0; }
  .topbar {
    grid-template-columns: 54px 1fr 54px;
    gap: 10px;
    padding: 10px 14px;
  }
  .header-logo { width: 52px; height: 52px; }
  .topbar h1 { font-size: 27px; }
  .workspace { padding: 12px; }
  .style-grid { grid-template-columns: repeat(2, 1fr); }
  .appearance-grid, .actions { grid-template-columns: 1fr; }
  .input-row { grid-template-columns: 1fr; }
  .qr-stage { min-height: 350px; overflow: auto; }
  footer { flex-wrap: wrap; }
  .version { width: 100%; margin-left: 0; }
}