:root {
  --bg: #ffffff;
  --panel: #f7f8fa;
  --border: #d7dbe0;
  --border-strong: #c3c9d1;
  --text: #2b3138;
  --muted: #7a828c;
  --label: #3c4450;
  --accent: #1f6fd6;
  --accent-dark: #1559ad;
  --required: #e02929;
  --readonly-bg: #eef0f3;
  --error: #d93025;
  --error-bg: #fdecea;
  --success: #1e7d34;
  --radius: 4px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #eceef1;
  color: var(--text);
  font-size: 14px;
  line-height: 1.4;
}

.page {
  max-width: 1200px;
  margin: 24px auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 1px 3px rgba(0,0,0,.06);
  overflow: hidden;
}

/* Header */
.page-header {
  padding: 18px 24px 10px;
}
.page-title {
  margin: 0 0 10px;
  font-size: 22px;
  font-weight: 700;
  color: #1b1f24;
}
.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
}
.breadcrumb a { color: var(--accent); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb .sep { color: var(--muted); }
.breadcrumb .current { color: var(--accent); }
.breadcrumb .home-icon { font-size: 13px; }

/* Sections */
.section {
  padding: 20px 24px;
  border-top: 1px solid #eceef1;
}
.section:first-of-type { border-top: none; }

.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px 26px;
}

.field { display: flex; flex-direction: column; }

label {
  font-weight: 700;
  color: var(--label);
  font-size: 13px;
  margin-bottom: 5px;
}
label .opt {
  font-weight: 400;
  color: var(--muted);
  font-size: 12px;
}
label .req { color: var(--required); margin-left: 2px; }

input[type="text"],
input[type="email"],
input[type="tel"],
input[type="number"],
input[type="date"],
select {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  font-size: 14px;
  color: var(--text);
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}

input:focus, select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(31,111,214,.15);
}

input[readonly] {
  background: var(--readonly-bg);
  color: #55606c;
  cursor: not-allowed;
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'><path fill='%23666' d='M1 1l5 5 5-5'/></svg>");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 30px;
}

/* Error states */
.field.invalid input,
.field.invalid select {
  border-color: var(--error);
  background: var(--error-bg);
}
.error-msg {
  color: var(--error);
  font-size: 12px;
  margin-top: 4px;
  display: none;
}
.field.invalid .error-msg { display: block; }

/* Footer / actions */
.actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  padding: 18px 24px 26px;
  background: var(--panel);
  border-top: 1px solid var(--border);
}
button {
  font-size: 14px;
  font-weight: 600;
  padding: 10px 22px;
  border-radius: var(--radius);
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-secondary { background: #fff; color: var(--label); border-color: var(--border-strong); }
.btn-secondary:hover { background: #f1f3f5; }

/* Banners */
.banner {
  margin: 0 24px 4px;
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 14px;
  display: none;
}
.banner.show { display: block; }
.banner.error { background: var(--error-bg); color: var(--error); border: 1px solid #f5c2c0; }
.banner.success { background: #e6f4ea; color: var(--success); border: 1px solid #b7dfc1; }

/* Output preview */
.result {
  margin: 0 24px 24px;
  padding: 16px;
  background: #f4faff;
  border: 1px solid #cfe4fb;
  border-radius: var(--radius);
  display: none;
}
.result.show { display: block; }
.result h3 { margin: 0 0 10px; font-size: 15px; color: var(--accent-dark); }
.result pre {
  margin: 0; white-space: pre-wrap; word-break: break-word;
  font-family: "SFMono-Regular", Consolas, monospace; font-size: 12.5px; color: #33475b;
}

@media (max-width: 900px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .grid { grid-template-columns: 1fr; }
  .page { margin: 0; border-radius: 0; }
}