/* =========================================================
   康軒版國小三年級上學期 (3上) 數學互動學習樂園 - 主樣式表
   ========================================================= */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;700;900&family=Fredoka:wght@500;600;700&display=swap');

:root {
  --bg-main: #FFFDF7;
  --bg-card: #FFFFFF;
  --bg-soft: #F3F7FF;
  --primary: #3B82F6;
  --primary-dark: #1D4ED8;
  --secondary: #F59E0B;
  --secondary-dark: #D97706;
  --accent-green: #10B981;
  --accent-green-dark: #059669;
  --accent-purple: #8B5CF6;
  --accent-pink: #EC4899;
  --accent-red: #EF4444;
  --text-main: #1E293B;
  --text-muted: #64748B;
  --border-color: #E2E8F0;
  --shadow-sm: 0 4px 12px rgba(30, 41, 59, 0.06);
  --shadow-md: 0 10px 25px rgba(30, 41, 59, 0.1);
  --radius-md: 16px;
  --radius-lg: 24px;
}

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

body {
  font-family: 'Noto Sans TC', 'Fredoka', sans-serif;
  background-color: var(--bg-main);
  background-image: 
    radial-gradient(#E0E7FF 1.5px, transparent 1.5px),
    radial-gradient(#FEF3C7 1.5px, #FFFDF7 1.5px);
  background-size: 40px 40px;
  background-position: 0 0, 20px 20px;
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  user-select: none;
}

/* 頂部導覽列 */
.top-header {
  background: linear-gradient(135deg, #1E40AF 0%, #3B82F6 55%, #2563EB 100%);
  color: white;
  padding: 1rem 1.5rem;
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.25);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.brand-area {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.brand-badge {
  background: #FBBF24;
  color: #78350F;
  font-weight: 900;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-size: 0.9rem;
  box-shadow: 0 3px 0 #B45309;
  letter-spacing: 0.5px;
}

.brand-title {
  font-size: 1.45rem;
  font-weight: 900;
  letter-spacing: 0.5px;
  text-shadow: 0 2px 4px rgba(0,0,0,0.18);
}

.score-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.star-counter {
  background: rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(8px);
  border: 2px solid rgba(255, 255, 255, 0.35);
  padding: 0.4rem 1rem;
  border-radius: 999px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 1.05rem;
}

.sound-btn {
  background: rgba(255,255,255,0.2);
  border: 2px solid rgba(255,255,255,0.4);
  color: white;
  padding: 0.4rem 0.85rem;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 700;
  font-family: inherit;
  transition: all 0.2s;
}
.sound-btn:hover {
  background: rgba(255,255,255,0.32);
  transform: translateY(-1px);
}

/* 5大單元主導覽按鈕 */
.unit-nav {
  max-width: 1280px;
  margin: 1.25rem auto 0.5rem;
  padding: 0 1rem;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.75rem;
}

@media (max-width: 950px) {
  .unit-nav {
    grid-template-columns: repeat(3, 1fr);
  }
}
@media (max-width: 600px) {
  .unit-nav {
    grid-template-columns: repeat(2, 1fr);
  }
}

.unit-tab {
  background: var(--bg-card);
  border: 3px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem 0.75rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 0.3rem;
  transition: all 0.22s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 4px 0 #CBD5E1;
  position: relative;
}

.unit-tab:hover {
  transform: translateY(-3px);
  border-color: #93C5FD;
}

.unit-tab.active {
  background: linear-gradient(180deg, #EFF6FF 0%, #DBEAFE 100%);
  border-color: var(--primary);
  box-shadow: 0 5px 0 var(--primary-dark);
  transform: translateY(-3px);
}

.unit-tab .unit-num {
  font-size: 0.78rem;
  font-weight: 800;
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  background: #E2E8F0;
  color: #475569;
}

.unit-tab.active .unit-num {
  background: var(--primary);
  color: white;
}

.unit-tab .unit-icon {
  font-size: 1.75rem;
  line-height: 1.2;
}

.unit-tab .unit-name {
  font-size: 1rem;
  font-weight: 900;
  color: var(--text-main);
}

.unit-tab .unit-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* 內容主容器 */
.main-container {
  max-width: 1280px;
  margin: 1rem auto 3rem;
  padding: 0 1rem;
}

.unit-section {
  display: none;
  animation: fadeIn 0.3s ease;
}

.unit-section.active {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 單元橫幅與子模式切換 (切換 Tabs) */
.unit-banner {
  background: white;
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.25rem;
  border: 3px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.unit-banner-info h2 {
  font-size: 1.4rem;
  font-weight: 900;
  color: #1E3A8A;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.unit-banner-info p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 0.25rem;
}

.submode-switcher {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  background: #F1F5F9;
  padding: 0.35rem;
  border-radius: 14px;
}

.submode-btn {
  border: none;
  background: transparent;
  padding: 0.55rem 1rem;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 800;
  font-size: 0.92rem;
  color: #475569;
  cursor: pointer;
  transition: all 0.2s;
}

.submode-btn:hover {
  color: var(--primary);
}

.submode-btn.active {
  background: var(--primary);
  color: white;
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.35);
}

.submode-panel {
  display: none;
}
.submode-panel.active {
  display: block;
}

/* 互動卡片通用樣式 */
.workspace-card {
  background: white;
  border-radius: var(--radius-lg);
  border: 3px solid var(--border-color);
  box-shadow: var(--shadow-md);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.story-prompt {
  background: linear-gradient(135deg, #FEF3C7 0%, #FDE68A 100%);
  border: 2px solid #F59E0B;
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}

.story-text {
  font-size: 1.1rem;
  font-weight: 700;
  color: #78350F;
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.story-badge {
  background: #D97706;
  color: white;
  padding: 0.25rem 0.65rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 900;
  white-space: nowrap;
}

/* 通用按鈕 */
.btn {
  border: none;
  border-radius: 12px;
  padding: 0.6rem 1.2rem;
  font-family: inherit;
  font-weight: 800;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.btn:active {
  transform: translateY(2px);
}

.btn-primary {
  background: var(--primary);
  color: white;
  box-shadow: 0 4px 0 var(--primary-dark);
}
.btn-primary:hover { background: #2563EB; }

.btn-Amber {
  background: var(--secondary);
  color: white;
  box-shadow: 0 4px 0 var(--secondary-dark);
}
.btn-Amber:hover { background: #D97706; }

.btn-green {
  background: var(--accent-green);
  color: white;
  box-shadow: 0 4px 0 var(--accent-green-dark);
}
.btn-green:hover { background: #059669; }

.btn-outline {
  background: #F8FAFC;
  color: #334155;
  border: 2px solid #CBD5E1;
  box-shadow: 0 3px 0 #CBD5E1;
}
.btn-outline:hover { background: #F1F5F9; }

/* 回饋訊息列 */
.feedback-banner {
  margin-top: 1rem;
  padding: 0.9rem 1.2rem;
  border-radius: 14px;
  font-weight: 800;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: #F1F5F9;
  color: #334155;
  border: 2px solid #CBD5E1;
}

.feedback-banner.success {
  background: #ECFDF5;
  color: #065F46;
  border-color: #10B981;
}

.feedback-banner.warning {
  background: #FFFBEB;
  color: #92400E;
  border-color: #F59E0B;
}

/* =========================================================
   單元 1：10000以內的數 (積木/錢幣拖拉 + 定位板 + 數線)
   ========================================================= */
.u1-top-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.rep-toggle {
  display: inline-flex;
  background: #E2E8F0;
  padding: 0.25rem;
  border-radius: 12px;
}

.rep-toggle button {
  border: none;
  background: transparent;
  padding: 0.45rem 0.9rem;
  border-radius: 9px;
  font-weight: 800;
  font-family: inherit;
  cursor: pointer;
  color: #475569;
}

.rep-toggle button.active {
  background: white;
  color: var(--primary-dark);
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
}

/* 拖拉來源庫 */
.manipulative-bank {
  background: #F8FAFC;
  border: 2px dashed #94A3B8;
  border-radius: var(--radius-md);
  padding: 1rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 700px) {
  .manipulative-bank {
    grid-template-columns: repeat(2, 1fr);
  }
}

.bank-item {
  background: white;
  border: 2px solid #CBD5E1;
  border-radius: 14px;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  cursor: grab;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 0 #CBD5E1;
}

.bank-item:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
  box-shadow: 0 6px 12px rgba(59, 130, 246, 0.18);
}

.bank-item:active {
  cursor: grabbing;
}

/* 位值定位板四欄 */
.place-value-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 768px) {
  .place-value-board {
    grid-template-columns: repeat(2, 1fr);
  }
}

.pv-column {
  border-radius: var(--radius-md);
  border: 3px solid #CBD5E1;
  background: #FAFAFA;
  display: flex;
  flex-direction: column;
  min-height: 270px;
  transition: all 0.2s;
  overflow: hidden;
}

.pv-column.drag-over {
  transform: scale(1.02);
  box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.3);
}

.pv-column[data-place="1000"] { border-color: #F87171; background: #FEF2F2; }
.pv-column[data-place="100"]  { border-color: #FBBF24; background: #FFFBEB; }
.pv-column[data-place="10"]   { border-color: #34D399; background: #ECFDF5; }
.pv-column[data-place="1"]    { border-color: #60A5FA; background: #EFF6FF; }

.pv-header {
  padding: 0.6rem;
  text-align: center;
  font-weight: 900;
  font-size: 1.15rem;
  color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.pv-column[data-place="1000"] .pv-header { background: #EF4444; }
.pv-column[data-place="100"]  .pv-header { background: #F59E0B; }
.pv-column[data-place="10"]   .pv-header { background: #10B981; }
.pv-column[data-place="1"]    .pv-header { background: #3B82F6; }

.pv-digit-display {
  font-family: 'Fredoka', sans-serif;
  font-size: 2.2rem;
  font-weight: 900;
  text-align: center;
  padding: 0.4rem 0;
  background: rgba(255,255,255,0.85);
  border-bottom: 2px dashed rgba(0,0,0,0.1);
}

.pv-dropzone {
  flex: 1;
  padding: 0.75rem;
  display: flex;
  flex-wrap: wrap;
  align-content: flex-start;
  justify-content: center;
  gap: 0.45rem;
  min-height: 150px;
}

.pv-footer {
  padding: 0.5rem;
  display: flex;
  justify-content: center;
  gap: 0.4rem;
  background: rgba(255,255,255,0.7);
  border-top: 1px solid rgba(0,0,0,0.06);
}

.pv-token {
  cursor: pointer;
  transition: transform 0.15s;
  animation: popIn 0.2s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.pv-token:hover {
  transform: scale(1.12);
}

@keyframes popIn {
  from { transform: scale(0.4); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

.readout-box {
  background: linear-gradient(135deg, #EEF2FF 0%, #E0E7FF 100%);
  border: 3px solid #818CF8;
  border-radius: var(--radius-md);
  padding: 1rem 1.5rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.readout-number {
  font-family: 'Fredoka', sans-serif;
  font-size: 2.4rem;
  font-weight: 900;
  color: #312E81;
}

.readout-chinese {
  font-size: 1.4rem;
  font-weight: 900;
  color: #4338CA;
  background: white;
  padding: 0.4rem 1rem;
  border-radius: 12px;
  border: 2px solid #C7D2FE;
}

/* 數線青蛙跳與比大小 */
.mountain-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin: 1rem 0;
}
@media (max-width: 768px) {
  .mountain-grid { grid-template-columns: repeat(2, 1fr); }
}

.mountain-card {
  background: linear-gradient(180deg, #F0FDF4 0%, #DCFCE7 100%);
  border: 3px solid #86EFAC;
  border-radius: 16px;
  padding: 1rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}
.mountain-card.selected {
  border-color: #16A34A;
  box-shadow: 0 0 0 4px rgba(22, 163, 74, 0.25);
  transform: translateY(-4px);
}

.compare-arena {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin: 1.25rem 0;
  flex-wrap: wrap;
}

.compare-num-box {
  font-family: 'Fredoka', sans-serif;
  font-size: 2.2rem;
  font-weight: 900;
  background: #F8FAFC;
  border: 3px solid #94A3B8;
  padding: 0.75rem 1.5rem;
  border-radius: 16px;
  min-width: 140px;
  text-align: center;
}

.sign-btn {
  width: 64px;
  height: 64px;
  font-size: 2rem;
  font-weight: 900;
  border-radius: 16px;
  border: 3px solid var(--primary);
  background: white;
  color: var(--primary-dark);
  cursor: pointer;
  transition: all 0.15s;
}
.sign-btn:hover, .sign-btn.active {
  background: var(--primary);
  color: white;
}

/* =========================================================
   單元 2：四位數的加減 (互動直式機 + 熱量與路程估算滑桿)
   ========================================================= */
.vertical-math-stage {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 900px) {
  .vertical-math-stage {
    grid-template-columns: 1fr;
  }
}

.vertical-grid-box {
  background: #FFFBEB;
  border: 3px solid #FCD34D;
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.v-table {
  width: 100%;
  max-width: 420px;
  margin: 0 auto;
  border-collapse: collapse;
  text-align: center;
}

.v-table th {
  padding: 0.4rem;
  font-size: 0.95rem;
  border-radius: 8px;
  color: white;
}

.v-table td {
  padding: 0.45rem;
  font-family: 'Fredoka', sans-serif;
  font-size: 2rem;
  font-weight: 800;
  position: relative;
}

.carry-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 34px;
  height: 34px;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 900;
  background: #FEE2E2;
  color: #DC2626;
  border: 2px solid #F87171;
  cursor: pointer;
  transition: transform 0.2s;
}
.carry-badge:hover {
  transform: scale(1.12);
}

.v-line {
  border-bottom: 4px solid #1E293B;
}

/* 估算滑桿區 */
.slider-box {
  background: #F8FAFC;
  border: 2px solid #CBD5E1;
  border-radius: 16px;
  padding: 1.25rem;
  margin: 1rem 0;
}

input[type="range"].edu-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 14px;
  border-radius: 999px;
  background: linear-gradient(90deg, #93C5FD 0%, #3B82F6 100%);
  outline: none;
  margin: 0.75rem 0;
}

input[type="range"].edu-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #F59E0B;
  border: 4px solid white;
  box-shadow: 0 3px 8px rgba(0,0,0,0.25);
  cursor: grab;
}

/* =========================================================
   單元 3：毫米 (可拖拉直尺 + 放大鏡 + 複名數計算)
   ========================================================= */
.ruler-canvas-wrap {
  position: relative;
  background: #F0F9FF;
  border: 3px solid #BAE6FD;
  border-radius: var(--radius-md);
  height: 340px;
  overflow: hidden;
  margin: 1rem 0;
  touch-action: none;
}

/* =========================================================
   單元 4：乘法 (陣列視覺化 + 直式乘法 + 連乘線段圖)
   ========================================================= */
.array-grid-container {
  background: #F8FAFC;
  border: 2px solid #CBD5E1;
  border-radius: var(--radius-md);
  padding: 1rem;
  min-height: 220px;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  justify-content: center;
}

.mul-blocks-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.6rem;
  background: white;
  border-radius: 10px;
  border: 1px solid #E2E8F0;
}

/* =========================================================
   單元 5：角與幾何 (扇子滑桿 + 可拖拉旋轉三角板 + 方格紙畫圖)
   ========================================================= */
.geometry-board {
  position: relative;
  background: #FFFFFF;
  background-image: 
    linear-gradient(to right, #E2E8F0 1px, transparent 1px),
    linear-gradient(to bottom, #E2E8F0 1px, transparent 1px);
  background-size: 30px 30px;
  border: 3px solid #94A3B8;
  border-radius: var(--radius-md);
  height: 400px;
  overflow: hidden;
  touch-action: none;
}

.angle-badge {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  border-radius: 999px;
  font-weight: 900;
  font-size: 1.05rem;
}
.angle-acute { background: #DCFCE7; color: #15803D; border: 2px solid #4ADE80; }
.angle-right { background: #FEE2E2; color: #B91C1C; border: 2px solid #F87171; }
.angle-obtuse { background: #FEF3C7; color: #B45309; border: 2px solid #FBBF24; }

.grid-canvas-board {
  background: #FFFFFF;
  border: 3px solid #64748B;
  border-radius: var(--radius-md);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 1rem;
  touch-action: none;
}