:root{
  --container: 880px;
  --radius: 12px;
  --border: #ddd;
  --muted: #555;
  --bg: #ffffff;
  --card-bg: #ffffff;
  --shadow: 0 1px 0 rgba(0,0,0,.03);
  --gap: 16px;
  --font: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

*{ box-sizing:border-box; }

.page{
  font-family: var(--font);
  margin: 0;
  color: #111;
  background: var(--bg);
}

.container{
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px;
}

.header{
  border-bottom: 1px solid var(--border);
  background: #fff;
}

.header__title{
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
}

.main{ min-height: 60vh; }

.footer{
  border-top: 1px solid var(--border);
  background: #fff;
}

.footer__note{
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.card{
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}

.card__title{
  margin: 0 0 12px 0;
  font-size: 18px;
}

.form{ display: grid; gap: var(--gap); }

.form__field{ display:grid; gap: 8px; }

.label{ font-weight: 700; }
.label__hint{ font-weight: 500; color: var(--muted); }

.input{
  width: 100%;
  padding: 10px 12px;
  font-size: 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
}

.help{
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.form__actions{ margin-top: 6px; }

.btn{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  font-size: 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  cursor: pointer;
}

.btn--primary{
  font-weight: 700;
}

.alert{
  border-radius: 10px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  font-size: 14px;
}

.alert--error{
  background: #fff2f2;
  border-color: #ffcccc;
}

.alert--success{
  background: #f1fff1;
  border-color: #c7f0c7;
}

.checkbox{ display:flex; gap: 10px; align-items:flex-start; }
.checkbox__input{ margin-top: 3px; }
.checkbox__text{ line-height: 1.4; }

.link{ color: inherit; }

.kv{ display: grid; gap: 10px; margin: 0; }
.kv__row{
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 10px;
  border-bottom: 1px solid #eee;
  padding: 10px 0;
}
.kv__key{ margin: 0; font-weight: 700; color:#444; }
.kv__value{ margin: 0; }

/* Breakpoints (mobile-first) */
@media (min-width: 768px){
  .header__title{ font-size: 26px; }
  .card{ padding: 22px; }
}

@media (min-width: 1024px){
  .container{ padding: 28px; }
}