:root {
  --bg-color: #0f172a;
  --card-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #38bdf8;
  --primary-hover: #0ea5e9;
  --border-color: #334155;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

input, select, textarea { min-width: 0; }

header {
  background-color: var(--card-bg);
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.brand-icon {
  font-size: 24px;
}

.brand-title {
  font-weight: 700;
  font-size: 16px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand-sub {
  font-size: 11px;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lang-switcher {
  display: flex;
  background: var(--bg-color);
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--border-color);
  flex-shrink: 0;
}

.lang-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 4px 8px;
  font-size: 12px;
  cursor: pointer;
}

.lang-btn.active {
  background: var(--border-color);
  color: var(--text-main);
  font-weight: bold;
}

.container {
  padding: 16px;
  max-width: 600px;
  margin: 0 auto;
}

.card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  border: 1px solid var(--border-color);
}

.card-title {
  font-size: 14px;
  font-weight: bold;
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.form-group {
  margin-bottom: 12px;
}

.form-group label {
  display: block;
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.form-row-2col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.form-input, .form-select {
  width: 100%;
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 10px;
  border-radius: 8px;
  font-size: 14px;
  outline: none;
}

.form-input:focus, .form-select:focus {
  border-color: var(--primary);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 12px;
  border-radius: 8px;
  font-weight: bold;
  font-size: 15px;
  cursor: pointer;
  transition: background 0.2s;
}

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

.result-box {
  background: var(--bg-color);
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 10px;
  text-align: center;
  border: 1px solid var(--border-color);
}