*, *::before, *::after { box-sizing: border-box; }
body {
  font-family: "Microsoft YaHei", sans-serif;
  background-color: #f5f7fa;
  color: #333;
  margin: 0;
  padding: 20px;
  overflow-x: hidden;
}
.inline-options {
  margin-top: 6px;
}
.inline-options label {
  display: inline-block;
  margin-right: 10px;
  font-weight: normal;
  margin-bottom: 6px;
}
.container {
  max-width: 1000px;
  margin: auto;
  background: white;
  border-radius: 10px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  padding: 20px;
  width: 100%;
  box-sizing: border-box;
}
h1 {
  text-align: center;
  color: #2c3e50;
  margin-bottom: 12px;
}
.tab-bar {
  display: flex;
  gap: 4px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 20px;
  border-bottom: 2px solid #e0e0e0;
}
.tab-link {
  display: inline-block;
  padding: 10px 16px;
  text-decoration: none;
  color: #666;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  font-weight: normal;
  white-space: nowrap;
}
.tab-link:hover {
  color: #3498db;
}
.tab-link.active {
  color: #3498db;
  border-bottom-color: #3498db;
  font-weight: bold;
}
.section {
  display: flex;
  gap: 20px;
  margin-bottom: 20px;
}
.half {
  flex: 1;
  padding: 15px;
  border: 1px solid #ddd;
  border-radius: 8px;
  background: #f9f9f9;
  min-width: 0;
}
.form-group {
  margin-bottom: 12px;
}
label {
  display: block;
  margin-bottom: 5px;
  font-weight: bold;
}
input[type="number"] {
  width: 100%;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
}
.result {
  margin-top: 20px;
  padding: 10px;
  background: #e8f5e8;
  border: 1px solid #a5d6a7;
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.4;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 6px 12px;
}
.result h3 {
  grid-column: 1 / -1;
  margin: 0 0 8px;
  font-size: 16px;
}
.result p {
  margin: 0;
}
#W_b_formula, #W_s_formula, #W_tot_formula,
.formula-mono {
  font-family: Menlo, Consolas, Monaco, "Courier New", monospace;
  font-size: 13px;
  overflow-wrap: anywhere;
}
.error {
  color: red;
  font-size: 14px;
  margin-top: 5px;
}
button {
  background-color: #3498db;
  color: white;
  border: none;
  padding: 10px 15px;
  border-radius: 4px;
  cursor: pointer;
  margin-top: 10px;
}
button:hover {
  background-color: #2980b9;
}
.footer {
  text-align: center;
  margin-top: 20px;
  font-size: 12px;
  color: #777;
}
.beian {
  text-align: center;
  margin-top: 20px;
  padding: 15px 0;
  font-size: 12px;
  color: #999;
  border-top: 1px solid #eee;
}
.beian a {
  color: #999;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}
.beian a:hover {
  color: #666;
}
.beian-icon {
  vertical-align: middle;
  height: 14px;
  width: auto;
}
.form-row {
  display: flex;
  gap: 10px;
  align-items: flex-end;
  flex-wrap: wrap;
}
.form-row .form-group {
  flex: 1 1 0;
  margin-bottom: 12px;
}
.inline-field {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}
.inline-field label {
  display: inline-block;
  margin: 0;
  font-weight: bold;
}
.inline-field input[type="number"] {
  width: 140px;
}
.config-warning {
  text-align: center;
  margin-bottom: 12px;
  padding: 8px 12px;
  background: #fff3cd;
  border: 1px solid #ffc107;
  border-radius: 4px;
  color: #856404;
  font-size: 14px;
  display: none;
}
.placeholder-message {
  text-align: center;
  padding: 60px 20px;
  color: #888;
  font-size: 16px;
  border: 1px dashed #ddd;
  border-radius: 8px;
  background: #fafafa;
}
@media (max-width: 360px) {
  .form-row {
    gap: 8px;
  }
  .form-row .form-group {
    flex-basis: 100%;
  }
}
@media (max-width: 900px) {
  .section {
    flex-direction: column;
    gap: 12px;
  }
  .result {
    grid-template-columns: 1fr;
  }
  .inline-field input[type="number"] {
    max-width: 160px;
    flex: 1 1 auto;
    min-width: 0;
    width: auto;
  }
  .tab-link {
    padding: 8px 12px;
    font-size: 14px;
  }
}