:root {
  --sky: #e8f4fd;
  --yellow: #FFD93D;
  --coral: #FF6B6B;
  --mint: #6BCB77;
  --blue: #4D96FF;
  --purple: #C77DFF;
  --orange: #FF9A3C;
  --bg: #fef9f0;
  --card: #ffffff;
  --text: #2d2d2d;
  --sub: #888;
  --border: #e0d6c8;
}

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

body {
  font-family: 'Noto Sans KR', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* 광고 영역 */
.ad-slot {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 90px;
  margin: 16px auto;
  max-width: 780px;
  border: 1px dashed #d8cdb9;
  border-radius: 12px;
  background: #fffdf8;
}

.ad-label {
  font-size: 12px;
  letter-spacing: 0.05em;
  color: #bbb;
}

/* HEADER */
.tools_header {
  background: linear-gradient(135deg, #FFD93D 0%, #FF9A3C 100%);
  padding: 36px 20px 28px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.tools_header::before {
  content: '';
  position: absolute;
  top: -40px; right: -40px;
  width: 180px; height: 180px;
  background: rgba(255,255,255,0.15);
  border-radius: 50%;
}
.tools_header::after {
  content: '';
  position: absolute;
  bottom: -60px; left: -30px;
  width: 220px; height: 220px;
  background: rgba(255,255,255,0.1);
  border-radius: 50%;
}
.tools_header h1 {
  font-family: 'Gaegu', cursive;
  font-size: 2.6rem;
  color: #fff;
  text-shadow: 2px 3px 0 rgba(0,0,0,0.12);
  position: relative; z-index:1;
  letter-spacing: -0.5px;
}
.tools_header p {
  color: rgba(255,255,255,0.9);
  font-size: 0.95rem;
  margin-top: 6px;
  position: relative; z-index:1;
}

/* MAIN */
.tools_main {
  max-width: 780px;
  margin: 0 auto;
  padding: 28px 16px 0;
}

/* INPUT SECTION */
.input-section {
  background: var(--card);
  border-radius: 24px;
  padding: 28px 24px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.07);
  border: 2px solid var(--border);
}

.input-section h2 {
  font-family: 'Gaegu', cursive;
  font-size: 1.4rem;
  margin-bottom: 18px;
  color: #444;
}

.fraction-inputs {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: flex-end;
}

.fraction-slot {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
  min-width: 100px;
  align-items: center;
}

.fraction-slot label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--sub);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.fraction-entry {
  display: flex;
  align-items: center;
  gap: 6px;
}

.fraction-entry:focus-within .frac-stack {
  box-shadow: 0 0 0 3px rgba(255,217,61,0.3);
  border-color: var(--yellow);
}

/* 세로 분수 입력 박스 */
.frac-stack {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #fafafa;
  border: 2px solid var(--border);
  border-radius: 16px;
  padding: 6px 10px 8px;
  transition: border-color 0.2s, box-shadow 0.2s;
  min-width: 72px;
}

.frac-stack .fs-label {
  font-size: 0.68rem;
  font-weight: 700;
  color: #bbb;
  letter-spacing: 0.04em;
  line-height: 1;
  margin-bottom: 2px;
}

.frac-stack input {
  width: 54px;
  height: 38px;
  border: none;
  background: transparent;
  text-align: center;
  font-family: 'Gaegu', cursive;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text);
  outline: none;
  -moz-appearance: textfield;
  line-height: 1;
  padding: 0;
}
.frac-stack input::-webkit-inner-spin-button { display: none; }

.frac-hline {
  width: 44px;
  height: 3px;
  background: #555;
  border-radius: 2px;
  margin: 2px 0;
}

.btn-add {
  display: flex;
  align-items: center;
  gap: 6px;
  background: #f0f0f0;
  border: 2px dashed #ccc;
  border-radius: 14px;
  padding: 12px 16px;
  cursor: pointer;
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.85rem;
  color: #888;
  flex: 0 0 auto; min-width: 90px; height: 52px;
  justify-content: center;
  transition: all 0.2s;
}
.btn-add:hover { background: #e8e8e8; border-color: #aaa; color: #555; }

.btn-remove {
  background: none; border: none; cursor: pointer;
  font-size: 1rem; color: #ccc; padding: 0 8px;
  transition: color 0.2s;
}
.btn-remove:hover { color: var(--coral); }

.actions {
  display: flex;
  gap: 10px;
  margin-top: 20px;
}

.btn-visualize {
  flex: 1;
  background: linear-gradient(135deg, #FF9A3C, #FF6B6B);
  color: #fff;
  border: none;
  border-radius: 14px;
  padding: 14px 20px;
  font-family: 'Gaegu', cursive;
  font-size: 1.3rem;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(255,107,107,0.3);
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn-visualize:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(255,107,107,0.4); }
.btn-visualize:active { transform: translateY(0); }

.btn-reset {
  background: #f0f0f0; border: 2px solid #e0e0e0;
  color: #888; border-radius: 14px; padding: 14px 18px;
  font-family: 'Noto Sans KR', sans-serif; font-size: 0.9rem;
  cursor: pointer; transition: all 0.2s;
}
.btn-reset:hover { background: #e8e8e8; }

/* QUICK EXAMPLES */
.quick-examples {
  margin-top: 14px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}
.quick-examples span {
  font-size: 0.8rem; color: var(--sub); white-space: nowrap;
}
.chip {
  background: #f4f4f4; border: 1px solid #e0e0e0;
  border-radius: 20px; padding: 5px 12px;
  cursor: pointer;
  transition: all 0.15s; color: #555;
  font-family: 'Gaegu', cursive; font-size: 0.95rem;
}
.chip:hover { background: var(--yellow); border-color: var(--yellow); color: #333; }

/* RESULT SECTION */
#result {
  margin-top: 28px;
  display: none;
}

.result-title {
  font-family: 'Gaegu', cursive;
  font-size: 1.6rem;
  margin-bottom: 18px;
  color: #444;
  text-align: center;
}

/* FRACTION CARDS */
.fraction-cards {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 24px;
}

.frac-card {
  background: var(--card);
  border-radius: 20px;
  padding: 20px 18px;
  flex: 1; min-width: 140px; max-width: 200px;
  box-shadow: 0 4px 18px rgba(0,0,0,0.07);
  border-top: 5px solid var(--accent);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  animation: popIn 0.35s cubic-bezier(0.34, 1.56, 0.64, 1) both;
}
@keyframes popIn {
  from { opacity: 0; transform: scale(0.8) translateY(10px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.frac-label {
  font-family: 'Gaegu', cursive;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  display: flex;
  flex-direction: column;
  align-items: center;
  line-height: 1;
  gap: 2px;
}
.frac-bar {
  width: 28px; height: 3px; border-radius: 2px;
  background: var(--accent);
}

.frac-desc {
  font-size: 0.78rem;
  color: var(--sub);
  text-align: center;
  line-height: 1.5;
}

.pie-wrap {
  width: 90px; height: 90px;
}

.pie-explain {
  background: #fffbe6;
  border: 2px dashed #FFD93D;
  border-radius: 14px;
  padding: 8px 12px;
  font-size: 0.8rem;
  color: #555;
  text-align: center;
  line-height: 1.6;
  width: 100%;
  position: relative;
}
.pie-explain::after {
  content: '';
  position: absolute;
  bottom: -10px; left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: #FFD93D;
}
.pie-explain strong { color: #e67e00; }

/* BAR VISUAL */
.bar-track {
  width: 100%;
  height: 22px;
  background: #f0f0f0;
  border-radius: 11px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  border-radius: 11px;
  background: var(--accent);
  transition: width 0.6s cubic-bezier(0.34, 1.2, 0.64, 1);
  position: relative;
  min-width: 4px;
}

/* COMPARISON SECTION */
.comparison-section {
  background: var(--card);
  border-radius: 20px;
  padding: 24px 22px;
  box-shadow: 0 4px 18px rgba(0,0,0,0.07);
  border: 2px solid var(--border);
  margin-bottom: 24px;
}

.comparison-section h3 {
  font-family: 'Gaegu', cursive;
  font-size: 1.3rem;
  margin-bottom: 16px;
  color: #444;
  text-align: center;
}

.comp-bar-wrap {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.comp-row {
  display: flex;
  align-items: center;
  gap: 10px;
  animation: slideIn 0.4s ease both;
}
@keyframes slideIn {
  from { opacity: 0; transform: translateX(-12px); }
  to   { opacity: 1; transform: translateX(0); }
}

.comp-label {
  min-width: 52px;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

/* 세로 분수 — 공용 컴포넌트 */
.kr-frac {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  font-family: 'Gaegu', cursive;
  font-weight: 700;
  line-height: 1;
  gap: 1px;
}
.kr-frac .kf-num  { font-size: 1.05rem; }
.kr-frac .kf-line { width: 22px; height: 2.5px; background: currentColor; border-radius: 2px; margin: 1px 0; }
.kr-frac .kf-den  { font-size: 1.05rem; }

.rank-item .kr-frac .kf-num,
.rank-item .kr-frac .kf-den { font-size: 1.25rem; }
.rank-item .kr-frac .kf-line { width: 28px; height: 3px; }

.comp-track {
  flex: 1;
  height: 28px;
  background: #f0f0f0;
  border-radius: 8px;
  overflow: hidden;
  position: relative;
}

.comp-fill {
  height: 100%;
  border-radius: 8px;
  background: var(--accent);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 8px;
  font-size: 0.78rem;
  color: white;
  font-weight: 700;
  transition: width 0.7s cubic-bezier(0.34, 1.1, 0.64, 1);
  min-width: 4px;
}

.comp-pct {
  min-width: 50px;
  font-size: 0.85rem;
  color: #888;
  font-weight: 700;
}

/* RANK SECTION */
.rank-section {
  background: linear-gradient(135deg, #e8f4fd, #fff9e6);
  border-radius: 20px;
  padding: 22px 22px;
  border: 2px solid var(--border);
  text-align: center;
  animation: fadeUp 0.5s ease both 0.2s;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}
.rank-section h3 {
  font-family: 'Gaegu', cursive;
  font-size: 1.3rem;
  margin-bottom: 12px;
  color: #444;
}

.rank-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  font-family: 'Gaegu', cursive;
  font-size: 1.5rem;
}

.rank-item {
  display: inline-flex;
  align-items: center;
  background: white;
  border-radius: 12px;
  padding: 8px 16px;
  border: 2px solid var(--accent);
  color: var(--accent);
  font-weight: 700;
}

.rank-sign {
  font-size: 1.1rem;
  color: #999;
  font-family: 'Noto Sans KR', sans-serif;
}

.tip-box {
  margin-top: 14px;
  background: white;
  border-radius: 12px;
  padding: 12px 16px;
  font-size: 0.88rem;
  color: #555;
  line-height: 1.7;
  border-left: 4px solid var(--yellow);
  text-align: left;
}
.tip-box strong { color: #333; }

/* 통분 설명 박스 */
.common-denom-box {
  margin-top: 16px;
  background: #f0f7ff;
  border: 2px solid #c0dff8;
  border-radius: 16px;
  padding: 18px 18px 16px;
  text-align: left;
}
.cd-title {
  font-family: 'Gaegu', cursive;
  font-size: 1.15rem;
  color: #2a6db5;
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.cd-intro {
  font-size: 0.85rem;
  color: #444;
  line-height: 1.75;
  margin-bottom: 14px;
}
.cd-intro strong { color: #2a6db5; }

.cd-steps {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.cd-step {
  background: white;
  border-radius: 12px;
  padding: 12px 14px;
  border-left: 4px solid #4D96FF;
  font-size: 0.84rem;
  color: #333;
  line-height: 1.7;
}
.cd-step-num {
  display: inline-block;
  background: #4D96FF;
  color: white;
  font-family: 'Gaegu', cursive;
  font-size: 0.9rem;
  font-weight: 700;
  border-radius: 50%;
  width: 22px; height: 22px;
  line-height: 22px;
  text-align: center;
  margin-right: 6px;
}
.cd-step strong { color: #e06c00; }
.cd-step .cd-frac-row {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 6px;
  flex-wrap: wrap;
}
.cd-arrow { color: #aaa; font-size: 1rem; }
.cd-highlight {
  background: #fff3cd;
  border-radius: 8px;
  padding: 2px 8px;
  border: 1.5px solid #ffc107;
  display: inline-flex;
  align-items: center;
}
.cd-bars {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 6px;
}
.cd-bar-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.cd-bar-label {
  min-width: 40px;
  font-family: 'Gaegu', cursive;
  font-size: 0.9rem;
  color: #555;
  text-align: right;
}
.cd-bar-track {
  flex: 1;
  height: 22px;
  background: #eee;
  border-radius: 6px;
  position: relative;
  overflow: visible;
}
.cd-bar-fill {
  height: 100%;
  border-radius: 6px;
  position: absolute; top: 0; left: 0;
}
.cd-bar-divider {
  position: absolute; top: 0; bottom: 0;
  width: 2px; background: rgba(255,255,255,0.8);
  z-index: 2;
}

/* ERROR */
.error-msg {
  color: var(--coral);
  font-size: 0.85rem;
  margin-top: 10px;
  display: none;
}

/* FOOTER */
.tools_footer {
  text-align: center;
  padding: 40px 20px 20px;
  font-size: 0.8rem;
  color: #bbb;
}

/* RESPONSIVE */
@media (max-width: 520px) {
  .tools_header h1 { font-size: 2rem; }
  .frac-card { min-width: 120px; }
  .fraction-inputs { gap: 8px; }
}