/* Charm — mobile-first tip calculator */

:root {
  --font-ui: "Outfit", "Segoe UI", sans-serif;
  --font-brand: "Fraunces", Georgia, serif;

  --bg0: #eef4f2;
  --bg1: #f7faf9;
  --surface: rgba(255, 255, 255, 0.78);
  --surface-solid: #ffffff;
  --ink: #12201c;
  --ink-soft: #4a5c56;
  --muted: #6d7f78;
  --line: rgba(18, 32, 28, 0.08);
  --accent: #0f766e;
  --accent-strong: #0b5f59;
  --accent-soft: rgba(15, 118, 110, 0.12);
  --accent-glow: rgba(15, 118, 110, 0.22);
  --charm: #c4512a;
  --charm-soft: rgba(196, 81, 42, 0.12);
  --danger: #b42318;
  --shadow: 0 10px 30px rgba(18, 32, 28, 0.08);
  --shadow-soft: 0 4px 14px rgba(18, 32, 28, 0.05);
  --radius-lg: 22px;
  --radius-md: 16px;
  --radius-sm: 12px;
  --tap: 48px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg0: #0b1220;
    --bg1: #121a2a;
    --surface: rgba(24, 34, 52, 0.82);
    --surface-solid: #182234;
    --ink: #edf3f1;
    --ink-soft: #b7c5bf;
    --muted: #8a9b94;
    --line: rgba(237, 243, 241, 0.1);
    --accent: #2dd4bf;
    --accent-strong: #5eead4;
    --accent-soft: rgba(45, 212, 191, 0.14);
    --accent-glow: rgba(45, 212, 191, 0.2);
    --charm: #fb923c;
    --charm-soft: rgba(251, 146, 60, 0.14);
    --shadow: 0 12px 36px rgba(0, 0, 0, 0.35);
    --shadow-soft: 0 4px 16px rgba(0, 0, 0, 0.25);
  }
}

html[data-theme="light"] {
  --bg0: #eef4f2;
  --bg1: #f7faf9;
  --surface: rgba(255, 255, 255, 0.78);
  --surface-solid: #ffffff;
  --ink: #12201c;
  --ink-soft: #4a5c56;
  --muted: #6d7f78;
  --line: rgba(18, 32, 28, 0.08);
  --accent: #0f766e;
  --accent-strong: #0b5f59;
  --accent-soft: rgba(15, 118, 110, 0.12);
  --accent-glow: rgba(15, 118, 110, 0.22);
  --charm: #c4512a;
  --charm-soft: rgba(196, 81, 42, 0.12);
  --shadow: 0 10px 30px rgba(18, 32, 28, 0.08);
  --shadow-soft: 0 4px 14px rgba(18, 32, 28, 0.05);
}

html[data-theme="dark"] {
  --bg0: #0b1220;
  --bg1: #121a2a;
  --surface: rgba(24, 34, 52, 0.82);
  --surface-solid: #182234;
  --ink: #edf3f1;
  --ink-soft: #b7c5bf;
  --muted: #8a9b94;
  --line: rgba(237, 243, 241, 0.1);
  --accent: #2dd4bf;
  --accent-strong: #5eead4;
  --accent-soft: rgba(45, 212, 191, 0.14);
  --accent-glow: rgba(45, 212, 191, 0.2);
  --charm: #fb923c;
  --charm-soft: rgba(251, 146, 60, 0.14);
  --shadow: 0 12px 36px rgba(0, 0, 0, 0.35);
  --shadow-soft: 0 4px 16px rgba(0, 0, 0, 0.25);
}

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

html {
  -webkit-text-size-adjust: 100%;
  color-scheme: light dark;
}

html[data-theme="light"] {
  color-scheme: light;
}

html[data-theme="dark"] {
  color-scheme: dark;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-ui);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(45, 212, 191, 0.16), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(196, 81, 42, 0.1), transparent 50%),
    linear-gradient(165deg, var(--bg0), var(--bg1) 45%, var(--bg0));
  background-attachment: fixed;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

button,
input,
select {
  font: inherit;
  color: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -48px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
}

.skip-link:focus {
  top: calc(12px + var(--safe-top));
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.app {
  width: min(100%, 440px);
  margin: 0 auto;
  padding:
    calc(16px + var(--safe-top))
    16px
    calc(28px + var(--safe-bottom));
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: 14px;
  animation: fade-up 0.55s var(--ease) both;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 2px 2px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.brand-mark {
  color: var(--accent);
  font-size: 1.15rem;
  animation: spark 2.8s ease-in-out infinite;
}

@keyframes spark {
  0%, 100% { transform: rotate(0deg) scale(1); opacity: 0.85; }
  50% { transform: rotate(12deg) scale(1.08); opacity: 1; }
}

.brand-name {
  margin: 0;
  font-family: var(--font-brand);
  font-size: clamp(2rem, 7vw, 2.45rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
}

.icon-btn {
  width: var(--tap);
  height: var(--tap);
  border-radius: 14px;
  display: grid;
  place-items: center;
  color: var(--ink-soft);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.2s var(--ease), background 0.2s ease;
}

.icon-btn:active {
  transform: scale(0.94);
}

.app-main {
  display: flex;
  flex-direction: column;
  gap: 14px;
  flex: 1;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 18px 16px;
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.field-label,
.section-title {
  display: block;
  margin: 0 0 10px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.bill-input-wrap {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 4px;
}

.currency-prefix {
  font-size: 2rem;
  font-weight: 600;
  color: var(--ink-soft);
  line-height: 1;
}

.bill-input {
  flex: 1;
  width: 100%;
  min-height: var(--tap);
  border: none;
  background: transparent;
  font-size: clamp(2.2rem, 10vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  caret-color: var(--accent);
}

.bill-input::placeholder {
  color: color-mix(in srgb, var(--muted) 55%, transparent);
}

.bill-input.is-shake {
  animation: shake 0.42s var(--ease);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  50% { transform: translateX(6px); }
  75% { transform: translateX(-4px); }
}

.tip-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.tip-btn {
  min-height: var(--tap);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--surface-solid) 70%, transparent);
  border: 1px solid var(--line);
  font-weight: 600;
  font-size: 1rem;
  color: var(--ink);
  transition:
    background 0.2s ease,
    color 0.2s ease,
    border-color 0.2s ease,
    transform 0.18s var(--ease),
    box-shadow 0.2s ease;
}

.tip-btn:active {
  transform: scale(0.96);
}

.tip-btn.is-active {
  background: var(--accent);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 8px 20px var(--accent-glow);
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .tip-btn.is-active {
    color: #042f2e;
  }
}

html[data-theme="dark"] .tip-btn.is-active {
  color: #042f2e;
}

.tip-btn-custom {
  grid-column: 1 / -1;
}

.custom-tip-row {
  margin-top: 12px;
  animation: fade-up 0.3s var(--ease) both;
}

.custom-tip-input {
  width: 100%;
  min-height: var(--tap);
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--surface-solid);
  padding: 0 14px;
  font-size: 1.15rem;
  font-weight: 600;
}

.results-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px 12px;
}

.result-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.result-item-total {
  grid-column: 2;
  grid-row: 1 / span 2;
  justify-content: center;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  background: var(--accent-soft);
}

.result-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.result-value {
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.result-item-total .result-value {
  font-size: clamp(1.55rem, 6vw, 1.85rem);
  color: var(--accent-strong);
}

.charm-section {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.charm-btn {
  min-height: 56px;
  border-radius: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 20px;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: #fff;
  background: linear-gradient(135deg, #d4552c, #a63d1f 55%, #c4512a);
  box-shadow: 0 12px 28px rgba(196, 81, 42, 0.28);
  transition: transform 0.2s var(--ease), filter 0.2s ease;
}

@media (prefers-color-scheme: dark) {
  html:not([data-theme="light"]) .charm-btn {
    color: #1c1208;
    background: linear-gradient(135deg, #fb923c, #f97316);
    box-shadow: 0 12px 28px rgba(251, 146, 60, 0.25);
  }
}

html[data-theme="dark"] .charm-btn {
  color: #1c1208;
  background: linear-gradient(135deg, #fb923c, #f97316);
  box-shadow: 0 12px 28px rgba(251, 146, 60, 0.25);
}

.charm-btn:hover {
  filter: brightness(1.05);
}

.charm-btn:active,
.charm-btn.is-pulse {
  transform: scale(0.97);
}

.charm-btn-sparkle {
  display: inline-block;
  animation: twinkle 1.8s ease-in-out infinite;
}

@keyframes twinkle {
  0%, 100% { transform: scale(1) rotate(0deg); }
  50% { transform: scale(1.15) rotate(-8deg); }
}

.charm-desc {
  margin: 0;
  text-align: center;
  font-size: 0.9rem;
  color: var(--muted);
}

.charm-suggestions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  animation: fade-up 0.35s var(--ease) both;
}

.charm-chip {
  min-height: 64px;
  padding: 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: transform 0.18s var(--ease), border-color 0.2s ease, background 0.2s ease;
}

.charm-chip:active {
  transform: scale(0.97);
}

.charm-chip.is-selected {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.charm-chip-amount {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.charm-chip-meta {
  font-size: 0.75rem;
  color: var(--muted);
}

.split-toggle {
  width: 100%;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-weight: 600;
  color: var(--ink);
}

.split-toggle .chevron {
  transition: transform 0.25s var(--ease);
  color: var(--muted);
}

.split-toggle.is-open .chevron {
  transform: rotate(180deg);
}

.split-body {
  margin-top: 14px;
  padding-top: 4px;
  animation: fade-up 0.3s var(--ease) both;
}

.split-control {
  display: grid;
  grid-template-columns: var(--tap) 1fr var(--tap);
  gap: 10px;
  align-items: center;
  margin-bottom: 14px;
}

.stepper-btn {
  width: var(--tap);
  height: var(--tap);
  border-radius: 14px;
  border: 1px solid var(--line);
  background: var(--surface-solid);
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--accent-strong);
  transition: transform 0.15s var(--ease);
}

.stepper-btn:active {
  transform: scale(0.94);
}

.split-input {
  width: 100%;
  min-height: var(--tap);
  text-align: center;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--surface-solid);
  font-size: 1.25rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.split-results {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(8, 14, 20, 0.45);
  opacity: 0;
  transition: opacity 0.28s ease;
  z-index: 40;
}

.overlay.is-open {
  opacity: 1;
}

.settings-sheet {
  position: fixed;
  left: 50%;
  bottom: 0;
  width: min(100%, 440px);
  transform: translate(-50%, 110%);
  z-index: 50;
  background: var(--surface-solid);
  border-radius: 24px 24px 0 0;
  box-shadow: var(--shadow);
  padding: 10px 18px calc(22px + var(--safe-bottom));
  transition: transform 0.32s var(--ease);
}

.settings-sheet.is-open {
  transform: translate(-50%, 0);
}

.settings-handle {
  width: 42px;
  height: 4px;
  border-radius: 999px;
  background: var(--line);
  margin: 4px auto 12px;
}

.settings-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.settings-header h2 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
}

.settings-body {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-top: 6px;
}

.settings-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: var(--tap);
  padding: 4px 0;
  font-weight: 500;
}

.settings-select {
  min-height: 42px;
  min-width: 148px;
  max-width: 58%;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg0) 70%, var(--surface-solid));
  padding: 0 12px;
}

.settings-note {
  margin: 4px 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

@media (min-width: 720px) {
  .app {
    padding-top: calc(28px + var(--safe-top));
  }

  .panel {
    padding: 20px 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}