:root {
  color-scheme: light;
  --ink: #10332f;
  --ink-soft: #36534e;
  --muted: #70827d;
  --muted-light: #94a49e;
  --page: #f3f6f2;
  --surface: #ffffff;
  --surface-soft: #edf3ee;
  --line: #dce6df;
  --accent: #1f9b78;
  --accent-dark: #0d6b50;
  --accent-pale: #d9f0e4;
  --sun: #f2b452;
  --shadow: 0 18px 42px rgba(18, 52, 44, 0.1);
  --radius-lg: 26px;
  --radius-md: 17px;
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", "YuGothic", Meiryo, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--page);
}

body {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
  background:
    radial-gradient(circle at 96% 4%, rgba(213, 234, 220, 0.7), transparent 26rem),
    var(--page);
  color: var(--ink);
  -webkit-font-smoothing: antialiased;
}

body.modal-open {
  overflow: hidden;
}

button,
input {
  font: inherit;
}

button {
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

button:focus-visible,
input:focus-visible,
a:focus-visible {
  outline: 3px solid rgba(31, 155, 120, 0.45);
  outline-offset: 3px;
}

.app-shell {
  width: min(100%, 500px);
  margin: 0 auto;
  padding: max(17px, env(safe-area-inset-top)) 16px max(30px, env(safe-area-inset-bottom));
}

.topbar,
.brand-lockup,
.rate-strip,
.utility-row,
.section-heading,
.modal-topline,
.modal-actions,
.input-amount-row,
.result-amount-row,
.offline-badge {
  display: flex;
  align-items: center;
}

.topbar {
  justify-content: space-between;
  min-height: 48px;
  margin-bottom: 12px;
}

.brand-lockup {
  gap: 10px;
  color: inherit;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 14px;
  background: var(--ink);
  color: #f1c86d;
  font-family: Georgia, serif;
  font-size: 25px;
  font-weight: 700;
  box-shadow: 0 8px 16px rgba(16, 51, 47, 0.16);
}

.brand-name,
.brand-subtitle {
  display: block;
}

.brand-name {
  letter-spacing: -0.04em;
  font-size: 17px;
  line-height: 1.15;
}

.brand-subtitle {
  margin-top: 3px;
  color: var(--muted);
  font-size: 10px;
  letter-spacing: 0.08em;
}

.header-button,
.text-button,
.utility-button,
.modal-button,
.close-button,
.mode-tab,
.key-button,
.history-item {
  border: 0;
  cursor: pointer;
}

.header-button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 38px;
  padding: 0 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.68);
  color: var(--ink-soft);
  font-size: 12px;
  font-weight: 700;
}

.header-button:active,
.text-button:active,
.utility-button:active,
.modal-button:active,
.close-button:active,
.history-item:active {
  transform: translateY(1px);
}

.header-button-icon {
  color: var(--accent-dark);
  font-size: 17px;
  line-height: 1;
}

.rate-strip {
  gap: 7px;
  min-height: 38px;
  margin-bottom: 11px;
  padding: 8px 12px;
  border: 1px solid rgba(201, 222, 209, 0.9);
  border-radius: 13px;
  background: rgba(231, 244, 234, 0.84);
  color: var(--ink-soft);
  font-size: 11px;
}

.rate-strip strong {
  color: var(--accent-dark);
  font-size: 12px;
  white-space: nowrap;
}

.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(31, 155, 120, 0.14);
}

.text-button {
  margin-left: auto;
  padding: 4px 1px 4px 6px;
  background: transparent;
  color: var(--accent-dark);
  font-size: 11px;
  font-weight: 800;
  white-space: nowrap;
}

.text-button-muted {
  color: var(--muted);
}

.converter-card {
  overflow: hidden;
  padding: 11px;
  border-radius: var(--radius-lg);
  background: var(--ink);
  box-shadow: 0 20px 42px rgba(9, 52, 44, 0.2);
}

.mode-switch {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 5px;
  padding: 4px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.09);
}

.mode-tab {
  min-height: 48px;
  padding: 5px 8px 6px;
  border-radius: 12px;
  background: transparent;
  color: rgba(255, 255, 255, 0.58);
  text-align: center;
  transition: color 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.mode-tab span,
.mode-tab small {
  display: block;
}

.mode-tab span {
  font-size: 13px;
  font-weight: 800;
}

.mode-tab small {
  margin-top: 2px;
  color: inherit;
  font-size: 9px;
  letter-spacing: 0.08em;
  opacity: 0.72;
}

.mode-tab.is-active {
  background: #f4faf5;
  color: var(--ink);
  box-shadow: 0 5px 12px rgba(0, 0, 0, 0.13);
}

.input-display {
  padding: 25px 12px 17px;
  text-align: right;
}

.display-label {
  color: rgba(231, 246, 238, 0.64);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-align: left;
}

.input-amount-row {
  justify-content: flex-end;
  gap: 10px;
  min-height: 72px;
}

.amount-input {
  width: 100%;
  min-width: 0;
  padding: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: #ffffff;
  font-size: clamp(50px, 14vw, 72px);
  font-variant-numeric: tabular-nums;
  font-weight: 750;
  letter-spacing: -0.075em;
  line-height: 1;
  text-align: right;
  caret-color: transparent;
}

.currency-code {
  flex: 0 0 auto;
  padding: 6px 8px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  color: #cbe5d8;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.display-helper {
  color: rgba(231, 246, 238, 0.48);
  font-size: 10px;
  text-align: left;
}

.conversion-divider {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 9px;
  padding: 0 12px 12px;
}

.conversion-divider > span:first-child,
.conversion-divider > span:last-child {
  height: 1px;
  background: rgba(255, 255, 255, 0.15);
}

.conversion-arrow {
  display: grid;
  width: 25px;
  height: 25px;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.17);
  border-radius: 50%;
  color: #a5dec0;
  font-size: 14px;
  line-height: 1;
}

.result-display {
  padding: 16px 17px 18px;
  border-radius: 18px;
  background: linear-gradient(145deg, #e5f3e9 0%, #d4eddf 100%);
  color: var(--ink);
}

.result-display .display-label {
  color: #5d7f71;
}

.result-amount-row {
  justify-content: flex-end;
  gap: 8px;
  min-height: 60px;
}

.result-amount {
  min-width: 0;
  flex: 1 1 auto;
  overflow: hidden;
  max-width: 100%;
  color: var(--ink);
  font-size: clamp(37px, 11vw, 57px);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  letter-spacing: -0.065em;
  line-height: 1;
  text-align: right;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.result-currency {
  color: var(--accent-dark);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.result-helper {
  margin-top: 4px;
  color: #638676;
  font-size: 10px;
  text-align: right;
}

.utility-row {
  gap: 8px;
  margin: 12px 0 18px;
}

.utility-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 44px;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--surface);
  color: var(--ink-soft);
  font-size: 11px;
  font-weight: 800;
  box-shadow: 0 5px 12px rgba(25, 71, 55, 0.04);
}

.utility-button:first-child {
  flex: 1;
}

.utility-button-secondary {
  flex: 0 0 auto;
  color: var(--muted);
}

.utility-icon {
  color: var(--accent-dark);
  font-size: 16px;
  font-weight: 900;
  line-height: 1;
}

.utility-button-secondary .utility-icon {
  font-size: 11px;
}

.utility-button-settings .utility-icon {
  font-size: 15px;
}

.section-heading {
  justify-content: space-between;
  gap: 12px;
}

.section-heading h2 {
  margin: 0;
  font-size: 14px;
  letter-spacing: -0.03em;
}

.section-heading p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: 10px;
}

.keypad-heading {
  margin-bottom: 9px;
}

.key-hint {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 8px;
  border-radius: 8px;
  background: rgba(237, 243, 238, 0.9);
  color: var(--muted);
  font-size: 10px;
  white-space: nowrap;
}

.key-hint b {
  color: var(--accent-dark);
  font-size: 12px;
}

.keypad {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  grid-auto-rows: minmax(57px, 1fr);
  gap: 8px;
}

.key-button {
  min-width: 0;
  min-height: 57px;
  padding: 3px;
  border: 1px solid #e3ebe5;
  border-radius: var(--radius-md);
  background: var(--surface);
  color: var(--ink);
  font-size: 25px;
  font-variant-numeric: tabular-nums;
  font-weight: 760;
  line-height: 1;
  box-shadow: 0 5px 0 #d9e5dc, 0 8px 15px rgba(22, 63, 49, 0.05);
  transition: transform 100ms ease, box-shadow 100ms ease, background 100ms ease;
}

.key-button:active {
  transform: translateY(4px);
  box-shadow: 0 1px 0 #d9e5dc, 0 3px 8px rgba(22, 63, 49, 0.05);
}

.key-button-action {
  background: #eef4ef;
  color: var(--muted);
  font-size: 18px;
}

.key-button-k {
  background: var(--accent);
  color: #ffffff;
  box-shadow: 0 5px 0 #0d795c, 0 9px 16px rgba(12, 109, 80, 0.18);
}

.key-button-k:active {
  box-shadow: 0 1px 0 #0d795c, 0 3px 8px rgba(12, 109, 80, 0.12);
}

.key-button-k-tall {
  grid-column: 4;
  grid-row: 3 / span 2;
}

.key-button-wide-label {
  grid-column: 1;
  grid-row: 4;
}

.key-button-zero {
  grid-column: 2;
  grid-row: 4;
}

.key-button-decimal {
  grid-column: 3;
  grid-row: 4;
}

.key-button-wide-label {
  font-size: 19px;
}

.history-section {
  margin-top: 25px;
}

.history-list {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.history-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  width: 100%;
  min-height: 58px;
  padding: 10px 13px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--ink);
  text-align: left;
  box-shadow: 0 4px 10px rgba(25, 71, 55, 0.03);
}

.history-item-main,
.history-item-result {
  min-width: 0;
}

.history-item-main strong,
.history-item-result strong,
.history-item-main small,
.history-item-result small {
  display: block;
}

.history-item-main strong {
  overflow: hidden;
  color: var(--ink-soft);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.history-item-main small,
.history-item-result small {
  margin-top: 3px;
  color: var(--muted);
  font-size: 9px;
}

.history-item-result {
  text-align: right;
}

.history-item-result strong {
  color: var(--accent-dark);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.history-item-result small {
  color: var(--muted);
}

.empty-history {
  margin-top: 10px;
  padding: 22px 12px;
  border: 1px dashed #cbdad0;
  border-radius: 15px;
  background: rgba(255, 255, 255, 0.35);
  color: var(--muted);
  text-align: center;
}

.empty-history[hidden] {
  display: none;
}

.empty-history-icon {
  display: inline-grid;
  width: 28px;
  height: 28px;
  place-items: center;
  margin-bottom: 4px;
  border-radius: 9px;
  background: var(--accent-pale);
  color: var(--accent-dark);
  font-size: 17px;
  font-weight: 900;
}

.empty-history p {
  margin: 0;
  font-size: 11px;
  font-weight: 700;
}

.empty-history small {
  display: block;
  margin-top: 4px;
  font-size: 10px;
}

.app-footer {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-top: 24px;
  color: var(--muted-light);
  font-size: 9px;
}

.offline-badge {
  gap: 6px;
  white-space: nowrap;
}

.offline-badge .status-dot {
  width: 5px;
  height: 5px;
  box-shadow: none;
}

.modal-backdrop {
  position: fixed;
  z-index: 20;
  inset: 0;
  display: grid;
  align-items: end;
  padding: 18px;
  background: rgba(7, 26, 23, 0.5);
  backdrop-filter: blur(5px);
}

.modal-backdrop[hidden] {
  display: none;
}

.settings-modal {
  width: min(100%, 460px);
  margin: 0 auto;
  padding: 22px 20px max(20px, env(safe-area-inset-bottom));
  border-radius: 25px;
  background: var(--surface);
  box-shadow: 0 -6px 35px rgba(5, 38, 30, 0.25);
  animation: slide-up 180ms ease-out;
}

@keyframes slide-up {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.modal-topline {
  justify-content: space-between;
}

.eyebrow {
  color: var(--accent-dark);
  font-size: 10px;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.close-button {
  display: grid;
  width: 33px;
  height: 33px;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-soft);
  color: var(--muted);
  font-size: 24px;
  line-height: 1;
}

.settings-modal h2 {
  margin: 14px 0 6px;
  font-size: 23px;
  letter-spacing: -0.06em;
}

.modal-description {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.rate-input-wrap {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-top: 18px;
  padding: 13px 15px;
  border: 2px solid var(--accent);
  border-radius: 15px;
  background: #f5fbf7;
  color: var(--ink);
}

.rate-prefix,
.rate-suffix {
  font-size: 13px;
  font-weight: 800;
  white-space: nowrap;
}

.rate-input-wrap input {
  width: 100%;
  min-width: 0;
  padding: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 29px;
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  letter-spacing: -0.05em;
  text-align: right;
}

.rate-suffix {
  color: var(--accent-dark);
}

.modal-note {
  margin: 10px 2px 0;
  color: var(--muted);
  font-size: 10px;
}

.modal-actions {
  gap: 8px;
  margin-top: 19px;
}

.modal-button {
  flex: 1;
  min-height: 49px;
  border-radius: 13px;
  font-size: 13px;
  font-weight: 800;
}

.modal-button-secondary {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
}

.modal-button-primary {
  background: var(--accent-dark);
  color: #ffffff;
  box-shadow: 0 5px 12px rgba(13, 107, 80, 0.2);
}

.toast {
  position: fixed;
  z-index: 30;
  right: 16px;
  bottom: max(18px, env(safe-area-inset-bottom));
  left: 16px;
  width: fit-content;
  max-width: calc(100% - 32px);
  margin: 0 auto;
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--ink);
  color: #ffffff;
  font-size: 11px;
  font-weight: 700;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 370px) {
  .app-shell {
    padding-right: 12px;
    padding-left: 12px;
  }

  .converter-card {
    padding: 9px;
  }

  .input-display {
    padding-top: 20px;
  }

  .keypad {
    gap: 6px;
  }

  .key-button {
    min-height: 53px;
  }

  .utility-button {
    padding-right: 9px;
    padding-left: 9px;
    font-size: 10px;
  }
}

/* Keep the calculator and the complete keypad within the first iPhone viewport. */
@media (max-width: 500px) and (max-height: 900px) {
  .converter-card {
    padding: 9px;
  }

  .input-display {
    padding: 17px 10px 10px;
  }

  .input-amount-row {
    min-height: 57px;
  }

  .amount-input {
    font-size: clamp(44px, 13vw, 64px);
  }

  .conversion-divider {
    padding: 0 10px 7px;
  }

  .result-display {
    padding: 12px 13px 13px;
  }

  .result-amount-row {
    min-height: 48px;
  }

  .result-amount {
    font-size: clamp(34px, 10vw, 50px);
  }

  .utility-row {
    margin: 9px 0 12px;
  }

  .keypad-heading {
    margin-bottom: 6px;
  }

  .keypad {
    grid-auto-rows: minmax(52px, 1fr);
    gap: 6px;
  }

  .key-button {
    min-height: 52px;
  }

  .history-section {
    margin-top: 19px;
  }
}

@media (min-width: 501px) {
  .app-shell {
    padding-top: 28px;
  }
}

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