* {
  box-sizing: border-box;
}

:root {
  --bg-gradient-start: #1e3c72;
  --bg-gradient-end: #2a5298;
  --card-bg: #ffffff;
  --title-color: #1e3c72;
  --subtitle-color: #666666;
  --text-color: #333333;
  --set-row-bg: #f4f6fb;
  --shadow-color: rgba(0, 0, 0, 0.25);
  --button-bg: #1e3c72;
  --button-bg-hover: #2a5298;
  --plus-color: #999999;
  --link-color: #1e3c72;
  --border-color: #e2e6ee;
}

[data-theme="dark"] {
  --bg-gradient-start: #0f1b30;
  --bg-gradient-end: #1a2b4a;
  --card-bg: #1e2532;
  --title-color: #8fb4ff;
  --subtitle-color: #a0a8b8;
  --text-color: #d5d9e2;
  --set-row-bg: #2a3346;
  --shadow-color: rgba(0, 0, 0, 0.5);
  --button-bg: #3a5a9a;
  --button-bg-hover: #4a6fb8;
  --plus-color: #b0b8c8;
  --link-color: #8fb4ff;
  --border-color: #33405a;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 20px 0;
  background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
  font-family: "Segoe UI", "맑은 고딕", sans-serif;
  transition: background 0.3s;
}

.card {
  position: relative;
  background: var(--card-bg);
  border-radius: 16px;
  padding: 40px 32px;
  width: 100%;
  max-width: 520px;
  text-align: center;
  box-shadow: 0 20px 40px var(--shadow-color);
  transition: background 0.3s;
}

.theme-toggle {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  background: var(--set-row-bg);
  cursor: pointer;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  transition: background 0.3s, transform 0.1s;
}

.theme-toggle:hover {
  transform: scale(1.08);
}

h1 {
  margin: 0 0 8px;
  font-size: 24px;
  color: var(--title-color);
  transition: color 0.3s;
}

p.subtitle {
  margin: 0 0 24px;
  color: var(--subtitle-color);
  font-size: 14px;
  transition: color 0.3s;
}

.sets {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 28px;
}

.set-row {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--set-row-bg);
  border-radius: 12px;
  padding: 10px 14px;
  transition: background 0.3s;
}

.set-label {
  flex: 0 0 32px;
  font-weight: bold;
  color: var(--title-color);
  font-size: 14px;
  transition: color 0.3s;
}

.balls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.plus {
  font-weight: bold;
  font-size: 16px;
  color: var(--plus-color);
  margin: 0 2px;
  transition: color 0.3s;
}

.ball {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: bold;
  font-size: 15px;
  box-shadow: inset 0 -4px 6px rgba(0, 0, 0, 0.2);
  animation: pop 0.35s ease;
}

@keyframes pop {
  from {
    transform: scale(0);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

/* 로또 공식 번호대 색상 */
.ball.yellow { background: #fbc400; }
.ball.blue   { background: #69c8f2; }
.ball.red    { background: #ff7272; }
.ball.gray   { background: #aaaaaa; }
.ball.green  { background: #b0d840; }

#generateBtn {
  border: none;
  background: var(--button-bg);
  color: #fff;
  font-size: 16px;
  font-weight: bold;
  padding: 14px 28px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

#generateBtn:hover {
  background: var(--button-bg-hover);
}

#generateBtn:active {
  transform: scale(0.97);
}

.info-card,
.contact-card,
.comments-card,
.content-card {
  background: var(--card-bg);
  border-radius: 16px;
  padding: 32px;
  width: 100%;
  max-width: 520px;
  box-shadow: 0 20px 40px var(--shadow-color);
  transition: background 0.3s;
}

.info-card h2,
.contact-card h2,
.comments-card h2,
.content-card h2 {
  margin: 0 0 6px;
  font-size: 19px;
  color: var(--title-color);
  transition: color 0.3s;
}

.contact-card p.subtitle {
  margin-bottom: 20px;
}

.info-card p,
.content-card p,
.content-card li {
  color: var(--text-color);
  font-size: 14px;
  line-height: 1.7;
  transition: color 0.3s;
}

.info-card h3,
.content-card h3 {
  font-size: 15px;
  color: var(--title-color);
  margin: 18px 0 6px;
  transition: color 0.3s;
}

.info-card h3:first-of-type,
.content-card h3:first-of-type {
  margin-top: 0;
}

.content-card ul,
.content-card ol {
  padding-left: 20px;
  margin: 8px 0;
}

.disclaimer {
  margin-top: 16px;
  padding: 12px 14px;
  border-radius: 10px;
  background: var(--set-row-bg);
  font-size: 13px;
  color: var(--subtitle-color);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  text-align: left;
}

.contact-form label {
  font-size: 13px;
  font-weight: bold;
  color: var(--title-color);
  margin-bottom: -6px;
  transition: color 0.3s;
}

.contact-form input,
.contact-form textarea {
  font-family: inherit;
  font-size: 14px;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid #d5d9e2;
  background: var(--set-row-bg);
  color: inherit;
  resize: vertical;
  transition: background 0.3s, border-color 0.2s;
}

.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--button-bg);
}

#contactSubmitBtn {
  border: none;
  background: var(--button-bg);
  color: #fff;
  font-size: 15px;
  font-weight: bold;
  padding: 12px 24px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

#contactSubmitBtn:hover {
  background: var(--button-bg-hover);
}

#contactSubmitBtn:active {
  transform: scale(0.97);
}

.contact-status {
  font-size: 13px;
  margin-top: 4px;
  display: none;
}

.contact-status.success {
  display: block;
  color: #2e8b57;
}

.contact-status.error {
  display: block;
  color: #e05555;
}

.comments-card h2 {
  margin-bottom: 16px;
}

.site-footer {
  width: 100%;
  max-width: 520px;
  text-align: center;
  padding: 4px 0 20px;
}

.site-footer nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-bottom: 8px;
}

.site-footer a {
  color: #ffffff;
  font-size: 13px;
  text-decoration: none;
  opacity: 0.85;
}

.site-footer a:hover {
  text-decoration: underline;
  opacity: 1;
}

.site-footer small {
  color: #ffffff;
  opacity: 0.6;
  font-size: 12px;
}

.content-card a {
  color: var(--link-color);
}

.back-link {
  display: inline-block;
  margin-top: 20px;
  font-size: 13px;
  color: var(--link-color);
}