/* ========== Liquid Glass Design System (B&W) ========== */

:root {
  /* Surface - white glass on black */
  --glass-bg: rgba(255, 255, 255, 0.07);
  --glass-bg-strong: rgba(255, 255, 255, 0.13);
  --glass-bg-active: rgba(255, 255, 255, 0.18);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-border-strong: rgba(255, 255, 255, 0.22);
  --glass-highlight: rgba(255, 255, 255, 0.1);
  --glass-shadow: rgba(0, 0, 0, 0.4);
  --glass-text: #ffffff;
  --glass-text-secondary: rgba(255, 255, 255, 0.5);
  --glass-accent: rgba(255, 255, 255, 0.18);
  --glass-accent-strong: rgba(255, 255, 255, 0.3);
  --glass-accent-text: #ffffff;
  --glass-danger: rgba(255, 255, 255, 0.1);
  --glass-danger-text: rgba(255, 255, 255, 0.8);
  --glass-inverted: #ffffff;
  --glass-inverted-text: #0a0a0a;

  /* Refraction */
  --glass-refract-top: rgba(255, 255, 255, 0.15);
  --glass-refract-bottom: rgba(0, 0, 0, 0.25);

  /* Depth */
  --glass-depth-1: 0 4px 16px rgba(0,0,0,0.3), inset 0 1px 0 rgba(255,255,255,0.08);
  --glass-depth-2: 0 8px 32px rgba(0,0,0,0.4), inset 0 1px 0 rgba(255,255,255,0.1);
  --glass-depth-3: 0 24px 64px rgba(0,0,0,0.5), inset 0 1px 0 rgba(255,255,255,0.1);

  /* Inverted button depth */
  --inverted-depth: 0 2px 8px rgba(0,0,0,0.4), inset 0 1px 0 rgba(255,255,255,0.3);

  /* Radii */
  --radius-sm: 14px;
  --radius-md: 20px;
  --radius-lg: 28px;
  --radius-xl: 36px;

  /* Motion */
  --ease-liquid: cubic-bezier(0.2, 0.8, 0.2, 1);
  --duration-fast: 0.2s;
  --duration-normal: 0.35s;
}

/* ========== Reset & Base ========== */

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, "SF Pro Display", "Helvetica Neue", Arial, sans-serif;
  color: var(--glass-text);
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;

  /* Solid black background */
  background: #0a0a0a;
  background-attachment: fixed;
  min-height: 100dvh;
  padding: env(safe-area-inset-top, 0) env(safe-area-inset-right, 0) env(safe-area-inset-bottom, 0) env(safe-area-inset-left, 0);
}

/* ========== Glass Utilities ========== */

.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(40px) saturate(1.1);
  -webkit-backdrop-filter: blur(40px) saturate(1.1);
  border: 0.5px solid var(--glass-border);
  box-shadow: var(--glass-depth-1);
}

.glass-sm {
  background: var(--glass-bg-strong);
  backdrop-filter: blur(20px) saturate(1.1);
  -webkit-backdrop-filter: blur(20px) saturate(1.1);
  border: 0.5px solid var(--glass-border);
  box-shadow: inset 0 1px 0 var(--glass-highlight);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
}

.glass-strong {
  background: var(--glass-bg-strong);
  backdrop-filter: blur(20px) saturate(1.1);
  -webkit-backdrop-filter: blur(20px) saturate(1.1);
  border: 0.5px solid var(--glass-border-strong);
  box-shadow: var(--glass-depth-2);
}

.glass-giant {
  background: rgba(30, 30, 30, 0.95);
  backdrop-filter: blur(40px) saturate(1.2);
  -webkit-backdrop-filter: blur(40px) saturate(1.2);
  border: 0.5px solid var(--glass-border-strong);
  box-shadow: var(--glass-depth-3);
}

/* ========== Header ========== */

.glass-header {
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 8px 16px;
  border-radius: 0 0 var(--radius-xl) var(--radius-xl);
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

#app-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.header-actions {
  display: flex;
  gap: 8px;
}

.sync-btn {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--glass-text);
  border: none;
  transition: transform var(--duration-fast) var(--ease-liquid),
              background var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
}

.sync-btn:active {
  transform: scale(0.92);
  background: var(--glass-accent) !important;
}

.sync-btn svg {
  color: var(--glass-text);
}

/* ========== Month Navigation ========== */

.month-nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 14px 16px;
}

.month-chevron {
  width: 48px;
  height: 48px;
  min-height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--glass-text);
  font-size: 24px;
  border: none;
  transition: transform var(--duration-fast) var(--ease-liquid),
              background var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
}

.month-chevron:active {
  transform: scale(0.92);
  background: var(--glass-accent) !important;
}

.month-label {
  font-size: 22px;
  font-weight: 700;
  color: var(--glass-text);
  min-width: 180px;
  text-align: center;
}

/* ========== Gauge Section ========== */

.gauge-section {
  padding: 16px;
}

.gauge-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  border-radius: var(--radius-xl);
  padding: 24px 20px;
  gap: 8px;
}

#gauge-canvas {
  max-width: 100%;
  height: auto;
}

.gauge-info {
  display: flex;
  gap: 24px;
  align-items: center;
  flex-wrap: wrap;
  justify-content: center;
}

.gauge-budget-target {
  font-size: 20px;
  font-weight: 700;
}

.gauge-spent-amount {
  font-size: 18px;
  color: var(--glass-text-secondary);
}

.edit-budget-btn {
  font-size: 16px;
  color: var(--glass-accent-text);
  background: none;
  border: none;
  cursor: pointer;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  transition: background var(--duration-fast) var(--ease-liquid);
  min-height: 44px;
  -webkit-tap-highlight-color: transparent;
}

.edit-budget-btn:active {
  background: var(--glass-accent);
}

/* ========== Expense Form ========== */

.form-section {
  padding: 0 16px 16px;
}

.expense-form-card {
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

/* Glass Input */

.glass-input {
  background: rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 0.5px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--glass-text);
  font-size: 17px;
  padding: 16px 18px;
  width: 100%;
  min-height: 52px;
  outline: none;
  transition: border-color var(--duration-fast) var(--ease-liquid),
              background var(--duration-fast) var(--ease-liquid);
  -webkit-appearance: none;
}

.amount-display {
  text-align: right;
  font-size: 36px;
  font-weight: 300;
  color: var(--glass-text);
  letter-spacing: -1px;
  padding: 16px 8px;
  min-height: 56px;
  cursor: pointer;
  user-select: none;
}

.amount-display:active {
  background: rgba(255, 255, 255, 0.16);
}

.glass-input::placeholder {
  color: var(--glass-text-secondary);
}

.glass-input.small {
  width: auto;
  padding: 12px 14px;
  min-height: 44px;
  font-size: 17px;
}

.form-row {
  display: flex;
  align-items: center;
}

/* Regular Toggle */

.regular-toggle-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  cursor: pointer;
}

.regular-toggle-label span {
  font-size: 17px;
  color: var(--glass-text);
}

.toggle-switch {
  width: 56px;
  height: 36px;
  min-height: 48px;
  background: rgba(120, 120, 128, 0.35);
  border-radius: 18px;
  position: relative;
  cursor: pointer;
  transition: background var(--duration-fast) var(--ease-liquid);
}

.toggle-switch.active {
  background: var(--glass-inverted);
}

.toggle-knob {
  position: absolute;
  width: 30px;
  height: 30px;
  background: #0a0a0a;
  border-radius: 50%;
  top: 3px;
  left: 3px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
  transition: transform var(--duration-fast) var(--ease-liquid);
}

.toggle-switch.active .toggle-knob {
  transform: translateX(20px);
}

/* Primary Button - inverted (white filled) */

.glass-btn-primary {
  background: var(--glass-inverted);
  border: none;
  box-shadow: var(--inverted-depth);
  border-radius: var(--radius-sm);
  color: var(--glass-inverted-text);
  font-size: 17px;
  font-weight: 600;
  padding: 16px 20px;
  min-height: 52px;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-liquid),
              opacity var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.glass-btn-primary:active {
  transform: scale(0.97);
  opacity: 0.85;
}

/* Secondary Button - glass */

.glass-btn-secondary {
  background: var(--glass-bg-strong);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 0.5px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: var(--glass-text);
  font-size: 17px;
  font-weight: 500;
  padding: 16px 20px;
  min-height: 52px;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-liquid),
              background var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
  flex: 1;
}

.glass-btn-secondary:active {
  transform: scale(0.97);
  background: var(--glass-accent-strong);
}

/* Danger Button - glass with red text */

.glass-btn-danger {
  background: var(--glass-danger);
  border: 0.5px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  color: var(--glass-danger-text);
  font-size: 17px;
  font-weight: 500;
  padding: 16px 20px;
  min-height: 52px;
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-liquid),
              background var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
  flex: 1;
}

.glass-btn-danger:active {
  transform: scale(0.97);
  background: rgba(255, 80, 60, 0.3);
}

/* ========== Keypad ========== */

.keypad-overlay {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 200;
  justify-content: center;
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.keypad-overlay.visible {
  display: flex;
}

.keypad-panel {
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  padding: 24px 20px calc(20px + env(safe-area-inset-bottom, 0));
  margin-top: auto;
  width: 100%;
}

.keypad-display {
  font-size: 48px;
  font-weight: 300;
  text-align: right;
  padding: 16px 8px 12px;
  min-height: 64px;
  color: var(--glass-text);
  letter-spacing: -1px;
}

.keypad-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-top: 8px;
}

.keypad-btn {
  background: var(--glass-bg-strong);
  backdrop-filter: blur(15px) saturate(1.1);
  -webkit-backdrop-filter: blur(15px) saturate(1.1);
  border: 0.5px solid var(--glass-border);
  box-shadow: inset 0 1px 0 var(--glass-highlight), 0 2px 8px var(--glass-shadow);
  border-radius: var(--radius-md);
  color: var(--glass-text);
  font-size: 32px;
  font-weight: 400;
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background var(--duration-fast) var(--ease-liquid),
              transform var(--duration-fast) var(--ease-liquid);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

.keypad-btn:active {
  background: var(--glass-bg-active);
  transform: scale(0.96);
}

.keypad-btn.action {
  background: var(--glass-inverted);
  color: var(--glass-inverted-text);
  box-shadow: var(--inverted-depth);
}

.keypad-btn.action:active {
  opacity: 0.85;
}

.keypad-btn.clear {
  background: rgba(255, 255, 255, 0.06);
  color: var(--glass-text-secondary);
}

.keypad-btn.clear:active {
  background: rgba(255, 255, 255, 0.12);
}

.keypad-btn.wide {
  grid-column: span 3;
  min-height: 60px;
  font-size: 28px;
}

/* ========== Expense List ========== */

.list-section {
  padding: 0 16px 120px;
}

#expenses-container {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.empty-state {
  text-align: center;
  padding: 40px 20px;
  border-radius: var(--radius-md);
  color: var(--glass-text-secondary);
}

.expense-group {
  margin-bottom: 8px;
}

.expense-group-header {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--glass-text-secondary);
  padding: 16px 8px 8px;
}

.expense-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  margin-top: 2px;
  border-radius: var(--radius-md);
  min-height: 56px;
  transition: background var(--duration-fast) var(--ease-liquid),
              transform var(--duration-fast) var(--ease-liquid);
  position: relative;
}

.expense-row:active {
  background: var(--glass-accent);
}

/* Swipe delete area - full height tap target */
.swipe-delete-bg {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 110px;
  background: rgba(255, 80, 60, 0.3);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 20px;
  color: var(--glass-danger-text);
  font-weight: 600;
  font-size: 17px;
}

.expense-purpose {
  font-size: 17px;
  font-weight: 500;
  flex: 1;
}

.expense-amount {
  font-size: 17px;
  font-weight: 600;
  margin-left: 12px;
  white-space: nowrap;
}

.expense-amount.regular-badge::after {
  content: ' \2601';
  font-size: 14px;
  margin-left: 4px;
  opacity: 0.5;
}

/* Swipe actions container */
.expense-row-wrapper {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-md);
}

.swipe-delete-bg {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 110px;
  background: rgba(255, 80, 60, 0.3);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 20px;
  color: var(--glass-danger-text);
  font-weight: 600;
  font-size: 17px;
}

/* ========== Sync Indicator ========== */

.sync-indicator {
  position: fixed;
  bottom: 24px;
  right: 16px;
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: var(--radius-lg);
  font-size: 14px;
  color: var(--glass-text-secondary);
  min-height: 40px;
  transition: opacity var(--duration-normal) var(--ease-liquid),
              transform var(--duration-normal) var(--ease-liquid);
  opacity: 0;
  pointer-events: none;
}

.sync-indicator.visible {
  opacity: 1;
  pointer-events: auto;
}

.sync-spinner circle {
  transform-origin: center;
}

/* ========== Modal Overlay ========== */

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 300;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-overlay.visible {
  display: flex;
}

.modal-overlay .glass-giant {
  width: 100%;
  max-width: 380px;
  border-radius: var(--radius-xl);
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-height: 90dvh;
  overflow-y: auto;
}

.modal-overlay h2 {
  font-size: 22px;
  font-weight: 700;
  text-align: center;
}

.budget-actions,
.user-actions,
.edit-actions {
  display: flex;
  gap: 10px;
}

.user-hint {
  font-size: 13px;
  color: var(--glass-text-secondary);
  text-align: center;
  line-height: 1.5;
}

.currency-row {
  display: flex;
  gap: 10px;
}

/* ========== Animations ========== */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}

.modal-enter {
  opacity: 0;
  transform: scale(0.92) translateY(20px);
}

.modal-enter-active {
  opacity: 1;
  transform: scale(1) translateY(0);
  transition: opacity var(--duration-normal) var(--ease-liquid),
              transform var(--duration-normal) var(--ease-liquid);
}

/* ========== Scrollbar ========== */

::-webkit-scrollbar { width: 0; height: 0; }

/* ========== Focus for accessibility ========== */

:focus-visible {
  outline: 2px solid var(--glass-inverted);
  outline-offset: 2px;
}