:root {
  --sf-color: #2563eb;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 24px 16px;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", sans-serif;
  background: #ffffff;
  color: #1f2937;
  line-height: 1.6;
}

.sf-container {
  max-width: 480px;
  margin: 0 auto;
}

.sf-title {
  font-size: 12px;
  font-weight: 400;
  margin: 0 0 20px;
  color: var(--sf-color);
}

.sf-field {
  margin-bottom: 16px;
}

.sf-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 400;
  margin-bottom: 6px;
}

.sf-input {
  width: 100%;
  padding: 10px 12px;
  font-size: 1rem;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  outline: none;
  background: #fff;
}

.sf-input:focus {
  border-color: var(--sf-color);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--sf-color) 25%, transparent);
}

/* デザインパターン: 四角い枠（既定） */
.sf-pattern-box .sf-input {
  border: 1px solid #d1d5db;
  border-radius: 6px;
}

/* デザインパターン: 下線のみ */
.sf-pattern-underline .sf-input {
  border: none;
  border-bottom: 2px solid #d1d5db;
  border-radius: 0;
  padding-left: 2px;
  padding-right: 2px;
  background: transparent;
}

.sf-pattern-underline .sf-input:focus {
  border-bottom-color: var(--sf-color);
  box-shadow: none;
}

.sf-pattern-underline .sf-button {
  background: #ffffff;
  color: var(--sf-color);
  border: 2px solid var(--sf-color);
}

.sf-pattern-underline .sf-button:hover {
  filter: none;
  background: color-mix(in srgb, var(--sf-color) 10%, white);
}

/* デザインパターン: 角丸（左右が丸い） */
.sf-pattern-rounded .sf-input {
  border: 1px solid #d1d5db;
  border-radius: 999px;
  padding-left: 18px;
  padding-right: 18px;
}

.sf-pattern-rounded .sf-button {
  border-radius: 999px;
}

.sf-submit-field {
  margin-top: 50px;
}

.sf-button {
  display: inline-block;
  width: 100%;
  padding: 12px 16px;
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--sf-color);
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

.sf-button:hover {
  filter: brightness(0.92);
}

.sf-message {
  padding: 20px;
  border-radius: 8px;
  background: #f3f4f6;
  text-align: center;
  white-space: pre-wrap;
}

.sf-message.sf-error {
  background: #fef2f2;
  color: #b91c1c;
}

.sf-errors {
  background: #fef2f2;
  color: #b91c1c;
  border-radius: 6px;
  padding: 10px 14px;
  margin-bottom: 16px;
  font-size: 0.9rem;
}

.sf-honeypot {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}