:root {
  color-scheme: light;
  --bg-gradient: linear-gradient(180deg, #f4fff7 0%, #e6f6ff 100%);
  --text-main: #1f2937;
  --text-sub: #4b5563;
  --wrap-bg: #ffffffcc;
  --wrap-shadow: 0 12px 28px rgba(26, 85, 64, 0.14);
  --info-bg: #f7fafc;
  --btn-main-bg: #10b981;
  --btn-main-text: #ffffff;
  --btn-sub-bg: #e5e7eb;
  --btn-sub-text: #111827;
  --card-front-bg: #bbf7d0;
  --card-back-bg: #ecfeff;
  --card-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
  --card-match-outline: #10b981;
  --message-color: #065f46;
}

body[data-theme="dark"] {
  color-scheme: dark;
  --bg-gradient: linear-gradient(180deg, #0f172a 0%, #111827 100%);
  --text-main: #f3f4f6;
  --text-sub: #d1d5db;
  --wrap-bg: #111827cc;
  --wrap-shadow: 0 12px 28px rgba(0, 0, 0, 0.35);
  --info-bg: #1f2937;
  --btn-main-bg: #059669;
  --btn-main-text: #ecfeff;
  --btn-sub-bg: #374151;
  --btn-sub-text: #f3f4f6;
  --card-front-bg: #166534;
  --card-back-bg: #1e3a8a;
  --card-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
  --card-match-outline: #34d399;
  --message-color: #6ee7b7;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Pretendard", "Noto Sans KR", system-ui, -apple-system, sans-serif;
  background: var(--bg-gradient);
  display: grid;
  place-items: center;
  color: var(--text-main);
}
.game-wrap { width: min(92vw, 680px); padding: 24px; border-radius: 18px; background: var(--wrap-bg); backdrop-filter: blur(2px); box-shadow: var(--wrap-shadow); }
.game-header h1 { margin: 0; }
.game-header p { margin-top: 8px; color: var(--text-sub); }
.game-info { display: flex; gap: 12px; justify-content: space-between; align-items: center; flex-wrap: wrap; margin: 18px 0; padding: 12px; border-radius: 12px; background: var(--info-bg); }
.action-buttons { display: flex; gap: 8px; }
#restartBtn, #themeToggleBtn { border: 0; padding: 8px 14px; border-radius: 8px; cursor: pointer; font-weight: 600; }
#restartBtn { background: var(--btn-main-bg); color: var(--btn-main-text); }
#themeToggleBtn { background: var(--btn-sub-bg); color: var(--btn-sub-text); }
#restartBtn:hover, #themeToggleBtn:hover { filter: brightness(0.95); }
.board { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.card { aspect-ratio: 1 / 1; border: 0; border-radius: 12px; cursor: pointer; position: relative; transform-style: preserve-3d; transition: transform 0.3s; box-shadow: var(--card-shadow); font-size: clamp(1.6rem, 4vw, 2rem); }
.card .face { position: absolute; inset: 0; display: grid; place-items: center; border-radius: 12px; backface-visibility: hidden; }
.card .front { background: var(--card-front-bg); }
.card .back { background: var(--card-back-bg); transform: rotateY(180deg); }
.card.flipped { transform: rotateY(180deg); }
.card.matched { outline: 2px solid var(--card-match-outline); cursor: default; }
.message { text-align: center; min-height: 1.4em; font-weight: 600; color: var(--message-color); margin: 14px 0 4px; }
.partner-wrap {
  margin-top: 24px;
  padding: 16px;
  border-radius: 12px;
  background: var(--info-bg);
}

.partner-wrap h2 {
  margin: 0 0 6px;
  font-size: 1.1rem;
}

.partner-desc {
  margin: 0 0 12px;
  color: var(--text-sub);
  font-size: 0.95rem;
}

.partner-form {
  display: grid;
  gap: 8px;
}

.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.partner-form label {
  font-size: 0.92rem;
  font-weight: 600;
}

.partner-form input,
.partner-form textarea {
  width: 100%;
  border: 1px solid #d1d5db;
  border-radius: 8px;
  padding: 10px;
  font: inherit;
  background: #fff;
  color: #111827;
}

body[data-theme="dark"] .partner-form input,
body[data-theme="dark"] .partner-form textarea {
  background: #111827;
  color: #f3f4f6;
  border-color: #4b5563;
}

.partner-form button {
  margin-top: 4px;
  border: 0;
  border-radius: 8px;
  padding: 10px 14px;
  font-weight: 700;
  cursor: pointer;
  background: var(--btn-main-bg);
  color: var(--btn-main-text);
}

.consent-check {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
  font-size: 0.9rem;
  color: var(--text-sub);
}

.consent-check input[type="checkbox"] {
  width: auto;
}