/* ================================================
   Number Puzzle Game — Shared Styles
   Style: Warm / playful / notebook-paper aesthetic
   ================================================ */

:root {
  /* — Color System — */
  --color-primary: #4A6741;
  --color-primary-light: #6B8F5E;
  --color-primary-lighter: #D4E6CE;
  --color-primary-lightest: #EDF5EA;

  --color-bg: #FDF8F0;
  --color-bg-warm: #F7F0E3;
  --color-bg-card: #FFFFFF;
  --color-bg-input: #FFFDF9;

  --color-text-primary: #2C2C2C;
  --color-text-secondary: #6B6B6B;
  --color-text-hint: #A0A0A0;
  --color-text-inverse: #FFFFFF;

  --color-border: #E2D9CC;
  --color-border-input: #D4C9B8;
  --color-border-focus: #4A6741;

  /* — State Colors — */
  --state-success: #4A6741;
  --state-error: #C0392B;
  --state-warning: #D4850A;
  --state-info: #5B8BA0;

  /* — Surface & Depth — */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.08);

  /* — Radius Scale — */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* — Spacing Scale — */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;

  /* — Typography — */
  --font-family-display: 'Georgia', 'Noto Serif SC', serif;
  --font-family-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-family-mono: 'Courier New', 'Source Code Pro', monospace;

  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 20px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;
  --font-size-3xl: 48px;
  --font-size-4xl: 64px;

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.2;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
}

.dark {
  --color-bg: #1A1A1A;
  --color-bg-warm: #222018;
  --color-bg-card: #2A2A2A;
  --color-bg-input: #333333;
  --color-text-primary: #E8E4DE;
  --color-text-secondary: #A09890;
  --color-text-hint: #706860;
  --color-border: #3A3630;
  --color-border-input: #4A4640;
  --color-primary-lighter: #2A3A26;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.15);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.3);
}

/* Notebook ruled-line background */
body {
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-family-body);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: repeating-linear-gradient(
    to bottom,
    transparent,
    transparent 31px,
    var(--color-border) 31px,
    var(--color-border) 32px
  );
  opacity: 0.25;
  pointer-events: none;
  z-index: 0;
}

body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 40px;
  width: 2px;
  height: 100%;
  background-color: var(--state-error);
  opacity: 0.12;
  pointer-events: none;
  z-index: 0;
}

main {
  position: relative;
  z-index: 1;
}

/* Scrollbar hide */
.no-scrollbar::-webkit-scrollbar { display: none; }
.no-scrollbar { -ms-overflow-style: none; scrollbar-width: none; }

/* Lucide icon fix */
[data-icon] {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  -webkit-mask-size: contain;
  mask-size: contain;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-position: center;
  mask-position: center;
  background-color: currentColor;
}

/* 3D tactile digit tiles */
.digit-box {
  width: 64px;
  height: 76px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  cursor: pointer;
  position: relative;
  font-family: var(--font-family-mono);
  font-size: 32px;
  font-weight: var(--font-weight-bold);
  color: var(--color-text-hint);
  background: linear-gradient(145deg, #F5EDE0 0%, #E8DCC8 40%, #DCCBB5 100%);
  border: 2px solid var(--color-border-input);
  box-shadow: 0 4px 0 0 #C4B49C, 0 6px 8px rgba(0,0,0,0.04), inset 0 1px 0 rgba(255,255,255,0.6);
  transition: transform 120ms cubic-bezier(.2,.8,.2,1), box-shadow 120ms cubic-bezier(.2,.8,.2,1);
  transform: perspective(400px) rotateX(2deg);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

.digit-box:hover {
  transform: perspective(400px) rotateX(0deg) translateY(-2px);
  box-shadow: 0 6px 0 0 #C4B49C, 0 8px 12px rgba(0,0,0,0.06), inset 0 1px 0 rgba(255,255,255,0.6);
}

.digit-box:active {
  transform: perspective(400px) rotateX(0deg) translateY(2px);
  box-shadow: 0 2px 0 0 #C4B49C, 0 3px 4px rgba(0,0,0,0.04), inset 0 1px 0 rgba(255,255,255,0.6);
  transition-duration: 60ms;
}

.digit-box:focus-visible,
.digit-box.active {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.digit-box.filled {
  color: var(--color-text-primary);
}

.digit-box.error {
  animation: shake 0.4s cubic-bezier(.36,.07,.19,.97) both;
  border-color: var(--state-error);
}

@keyframes shake {
  10%, 90% { transform: translate3d(-1px, 0, 0); }
  20%, 80% { transform: translate3d(2px, 0, 0); }
  30%, 50%, 70% { transform: translate3d(-4px, 0, 0); }
  40%, 60% { transform: translate3d(4px, 0, 0); }
}

/* Confirm button */
.confirm-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 48px;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  font-family: var(--font-family-body);
  color: var(--color-text-inverse);
  background-color: var(--color-primary);
  box-shadow: 0 2px 0 0 #3A5234, var(--shadow-sm);
  transition: transform 120ms cubic-bezier(.2,.8,.2,1), box-shadow 120ms cubic-bezier(.2,.8,.2,1), background-color 160ms cubic-bezier(.2,.8,.2,1);
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
}

.confirm-btn:hover {
  background-color: var(--color-primary-light);
  transform: translateY(-1px);
  box-shadow: 0 3px 0 0 #3A5234, var(--shadow-md);
}

.confirm-btn:active {
  transform: translateY(1px);
  box-shadow: 0 0px 0 0 #3A5234, var(--shadow-sm);
  transition-duration: 60ms;
}

.confirm-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Clue cards */
.clue-card {
  padding: 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background-color: var(--color-bg-card);
  box-shadow: var(--shadow-sm);
  transition: transform 160ms cubic-bezier(.2,.8,.2,1), box-shadow 160ms cubic-bezier(.2,.8,.2,1);
}

.clue-card:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* Clue badge */
.clue-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background-color: var(--color-primary-lightest);
  color: var(--color-primary);
  font-family: var(--font-family-body);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
}

/* Clue digits */
.clue-digit {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background-color: var(--color-bg-input);
  color: var(--color-text-primary);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
}

/* Digit states */
.clue-digit--wrong {
  color: var(--state-error);
  text-decoration: line-through;
  border-color: var(--state-error);
  opacity: 0.7;
  background-color: #FDF0EF;
}

.clue-digit--correct-pos {
  color: var(--state-success);
  border-color: var(--state-success);
  background-color: var(--color-primary-lightest);
  box-shadow: 0 0 0 1px var(--state-success);
}

.clue-digit--wrong-pos {
  color: var(--state-warning);
  border-color: var(--state-warning);
  background-color: #FEF7E7;
}

/* Clue hint text */
.clue-hint {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: var(--line-height-normal);
}

/* Action buttons */
.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 44px;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  font-family: var(--font-family-body);
  white-space: nowrap;
  transition: transform 120ms cubic-bezier(.2,.8,.2,1), box-shadow 120ms cubic-bezier(.2,.8,.2,1), background-color 160ms cubic-bezier(.2,.8,.2,1);
  -webkit-tap-highlight-color: transparent;
  border: none;
}

.action-btn--secondary {
  background-color: var(--color-primary-lightest);
  color: var(--color-primary);
  border: 1px solid var(--color-primary-lighter);
}

.action-btn--secondary:hover {
  background-color: var(--color-primary-lighter);
  transform: translateY(-1px);
}

.action-btn--secondary:active {
  transform: translateY(1px);
  transition-duration: 60ms;
}

.action-btn--outline {
  background-color: transparent;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

.action-btn--outline:hover {
  background-color: var(--color-bg-warm);
  border-color: var(--color-border-input);
  transform: translateY(-1px);
}

.action-btn--outline:active {
  transform: translateY(1px);
  transition-duration: 60ms;
}

.action-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Numpad */
.numpad-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.25);
  z-index: 40;
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms ease;
}

.numpad-overlay.open {
  opacity: 1;
  pointer-events: auto;
}

.numpad-sheet {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: var(--spacing-md) var(--spacing-lg) calc(var(--spacing-lg) + env(safe-area-inset-bottom));
  z-index: 50;
  transform: translateY(100%);
  transition: transform 300ms cubic-bezier(.2,.8,.2,1);
  max-width: 600px;
  margin: 0 auto;
}

.numpad-sheet.open {
  transform: translateY(0);
}

.numpad-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-sm);
}

.numpad-key {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--color-bg-warm);
  border: 1px solid var(--color-border);
  font-family: var(--font-family-mono);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: transform 80ms ease, background-color 80ms ease;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

.numpad-key:active {
  transform: scale(0.96);
  background: var(--color-primary-lighter);
}

.numpad-key--action {
  background: var(--color-primary-lightest);
  color: var(--color-primary);
  font-family: var(--font-family-body);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
}

/* Toast */
.toast {
  position: fixed;
  top: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  background: var(--color-text-primary);
  color: var(--color-text-inverse);
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms ease, transform 200ms ease;
  z-index: 60;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .digit-box, .confirm-btn, .clue-card, .action-btn, .numpad-sheet, .numpad-overlay, .toast {
    transition-duration: 0.01ms !important;
  }
}

/* Responsive digit boxes */
@media (max-width: 360px) {
  .digit-box {
    width: 56px;
    height: 66px;
    font-size: 26px;
  }
  .clue-digit {
    width: 32px;
    height: 32px;
    font-size: var(--font-size-base);
  }
}

@media (min-width: 640px) {
  .digit-box {
    width: 72px;
    height: 86px;
    font-size: 36px;
  }
}