:root {
  color-scheme: dark;
  --bg: #0f172a;
  --surface: #1e293b;
  --surface-hover: #253349;
  --well: #131c31;
  --border: #334155;
  --border-strong: #475569;
  --line: rgba(148, 163, 184, 0.12);
  --text: #e2e8f0;
  --muted: #94a3b8;
  --placeholder: #7c8aa0;
  --accent: #93c5fd;
  --accent-hover: #bfdbfe;
  --accent-ink: #0b1324;
  --accent-soft: rgba(147, 197, 253, 0.12);
  --accent-line: rgba(147, 197, 253, 0.5);
  --danger: #fca5a5;
  --radius: 12px;
  --radius-small: 10px;
  --shadow: 0 1px 2px rgba(2, 6, 23, 0.35), 0 12px 32px -14px rgba(2, 6, 23, 0.7);
  --speed: 180ms;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
}

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

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--bg);
  background-image:
    radial-gradient(56rem 26rem at 100% -6rem, rgba(147, 197, 253, 0.09), transparent 70%),
    radial-gradient(40rem 22rem at -12% 0, rgba(147, 197, 253, 0.05), transparent 70%);
  background-repeat: no-repeat;
  color: var(--text);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
p {
  margin: 0;
}

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

button {
  cursor: pointer;
  touch-action: manipulation;
}

button:disabled {
  cursor: default;
  opacity: 0.4;
}

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

[hidden] {
  display: none !important;
}

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

.clipboard-buffer {
  position: fixed;
  top: 0;
  left: 0;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.icon {
  width: 20px;
  height: 20px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- Page frame ---------- */

.app {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 1200px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 0 16px 16px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 0 10px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.logo {
  width: 38px;
  height: 38px;
  flex: none;
  filter: drop-shadow(0 6px 14px rgba(147, 197, 253, 0.2));
}

.brand-text {
  min-width: 0;
}

.brand h1 {
  font-size: 1.1875rem;
  font-weight: 750;
  line-height: 1.2;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.tagline {
  display: none;
  color: var(--muted);
  font-size: 0.8125rem;
}

.top-actions {
  display: flex;
  flex: none;
  gap: 8px;
}

.footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 20px;
  margin-top: auto;
  padding: 10px 0 0; /* the 40 px link box supplies the rest of the space */
  color: var(--muted);
  font-size: 0.8125rem;
}

.footer a {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 0 4px;
  color: var(--accent);
  text-decoration: none;
  border-radius: 8px;
}

.footer a:hover {
  text-decoration: underline;
}

.kbd-hints {
  display: none;
  flex-wrap: wrap;
  gap: 6px 14px;
}

.hint {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

kbd {
  display: inline-block;
  min-width: 22px;
  padding: 0 6px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
  font: 600 0.75rem/1.5 var(--font);
  text-align: center;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-small);
  background: var(--surface);
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  transition:
    background-color var(--speed) ease,
    border-color var(--speed) ease,
    color var(--speed) ease,
    transform var(--speed) ease;
}

.btn:hover {
  background: var(--surface-hover);
  border-color: var(--border-strong);
}

.btn:active {
  transform: translateY(1px);
}

.btn .icon {
  width: 18px;
  height: 18px;
}

.btn-accent {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.btn-accent:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-quiet {
  padding: 0 10px;
  background: transparent;
  border-color: transparent;
  color: var(--muted);
}

.btn-quiet:hover {
  background: rgba(148, 163, 184, 0.1);
  border-color: transparent;
  color: var(--text);
}

.btn-small {
  font-size: 0.875rem;
}

.btn-lang {
  min-width: 48px;
  padding: 0 12px;
  color: var(--accent);
  letter-spacing: 0.06em;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  flex: none;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 1px solid transparent;
  border-radius: var(--radius-small);
  background: transparent;
  color: var(--muted);
  transition:
    background-color var(--speed) ease,
    color var(--speed) ease,
    transform var(--speed) ease;
}

.icon-btn:hover:not(:disabled) {
  background: rgba(148, 163, 184, 0.12);
  color: var(--text);
}

.icon-btn:active:not(:disabled) {
  transform: scale(0.94);
}

.icon-btn .icon {
  width: 18px;
  height: 18px;
}

/* ---------- Category chips ---------- */

.chips-wrap {
  margin: 0 -16px;
}

.chips {
  position: relative;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  padding: 4px 16px 10px;
  scrollbar-width: none;
  -webkit-mask-image: linear-gradient(90deg, transparent 0, #000 14px, #000 calc(100% - 28px), transparent);
  mask-image: linear-gradient(90deg, transparent 0, #000 14px, #000 calc(100% - 28px), transparent);
}

.chips::-webkit-scrollbar {
  display: none;
}

.chips.is-dragging {
  cursor: grabbing;
  user-select: none;
}

.chip {
  flex: none;
  min-height: 40px;
  padding: 0 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
  transition:
    background-color var(--speed) ease,
    border-color var(--speed) ease,
    color var(--speed) ease,
    box-shadow var(--speed) ease;
}

.chip:hover {
  border-color: var(--border-strong);
  color: var(--text);
}

.chip[aria-checked="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  box-shadow: 0 8px 20px -10px rgba(147, 197, 253, 0.75);
}

/* ---------- Layout and cards ---------- */

.layout {
  display: grid;
  gap: 16px;
  align-items: start;
  padding-top: 4px;
}

.col {
  display: grid;
  gap: 16px;
  min-width: 0;
}

.card {
  min-width: 0;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.card-title {
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.section-title {
  color: var(--muted);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-title:focus {
  outline: none;
}

/* ---------- Smart input line ---------- */

.query-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr); /* lets the text field shrink on narrow phones */
  gap: 8px;
}

.query-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 4px 4px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--well);
  transition:
    border-color var(--speed) ease,
    box-shadow var(--speed) ease;
}

.query-row:focus-within {
  border-color: var(--accent-line);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.query-row > .icon {
  color: var(--muted);
}

.query-input {
  flex: 1;
  min-width: 0;
  min-height: 40px;
  border: 0;
  background: transparent;
  font-size: 1.0625rem;
}

.query-input:focus {
  outline: none;
}

.query-input::placeholder {
  color: var(--placeholder);
}

.query-status {
  display: flex;
  align-items: flex-start;
  gap: 6px;
  min-height: 1.5rem;
  color: var(--muted);
  font-size: 0.875rem;
}

.query-status .icon {
  width: 16px;
  height: 16px;
  margin-top: 2px;
}

.query-status.is-preview {
  color: var(--accent);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.query-status.is-error {
  color: var(--danger);
}

/* ---------- Converter ---------- */

.converter .card-head {
  align-items: flex-start;
  margin-bottom: 8px;
}

.card-head-text {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0 12px;
  min-width: 0;
  padding-top: 4px;
}

.formula {
  color: var(--muted);
  font-size: 0.875rem;
  font-variant-numeric: tabular-nums;
  overflow-wrap: anywhere;
}

.star {
  margin: -6px -6px 0 0;
}

.star .icon {
  width: 22px;
  height: 22px;
  transition:
    transform var(--speed) ease,
    fill var(--speed) ease;
}

.star[aria-pressed="true"] {
  color: var(--accent);
}

.star[aria-pressed="true"] .icon {
  fill: currentColor;
  transform: scale(1.06);
}

.pair {
  display: grid;
  gap: 8px;
}

.side {
  display: grid;
  gap: 4px;
  min-width: 0;
  padding: 10px 12px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--well);
  transition:
    border-color var(--speed) ease,
    box-shadow var(--speed) ease;
}

.side:focus-within {
  border-color: var(--accent-line);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.side-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: -6px -6px -4px 0;
}

.side-tools {
  display: flex;
  gap: 2px;
}

.amount {
  width: 100%;
  min-width: 0;
  min-height: 40px;
  padding: 0 0 6px;
  border: 0;
  background: transparent;
  font-size: 1.75rem;
  font-weight: 650;
  line-height: 1.25;
  letter-spacing: -0.015em;
  font-variant-numeric: tabular-nums;
}

.amount:focus {
  outline: none;
}

.amount[aria-invalid="true"] {
  color: var(--danger);
}

.unit-select {
  width: 100%;
  min-height: 44px;
  padding: 0 40px 0 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-small);
  background: var(--surface)
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E")
    no-repeat right 12px center / 18px 18px;
  font-size: 1rem;
  text-overflow: ellipsis;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: border-color var(--speed) ease;
}

.unit-select:hover {
  border-color: var(--border-strong);
}

.unit-select option {
  background: var(--surface);
  color: var(--text);
}

.field-error {
  color: var(--danger);
  font-size: 0.8125rem;
}

.swap {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  justify-self: center;
  width: 44px;
  height: 44px;
  margin: -18px 0;
  padding: 0;
  border: 1px solid var(--border-strong);
  border-radius: 50%;
  background: var(--surface);
  color: var(--accent);
  box-shadow: 0 0 0 4px var(--surface);
  transition:
    background-color var(--speed) ease,
    border-color var(--speed) ease;
}

.swap:hover {
  background: var(--surface-hover);
  border-color: var(--accent-line);
}

.swap .icon {
  transform: rotate(calc(90deg + var(--turns, 0deg)));
  transition: transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}

/* ---------- Favorites and recents ---------- */

.lists {
  display: grid;
  gap: 18px;
}

.list-block {
  min-width: 0;
}

.list-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  min-height: 28px;
  margin-bottom: 6px;
}

.list-head .btn {
  margin: -6px -8px -6px 0;
}

.fav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.fav {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 40px;
  padding: 0 14px 0 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--well);
  font-size: 0.875rem;
  font-weight: 600;
  transition:
    background-color var(--speed) ease,
    border-color var(--speed) ease,
    color var(--speed) ease;
}

.fav:hover {
  background: var(--surface-hover);
  border-color: var(--border-strong);
}

.fav .icon {
  width: 14px;
  height: 14px;
  color: var(--accent);
  fill: currentColor;
  stroke-width: 1.5;
}

.fav[aria-current="true"] {
  background: var(--accent-soft);
  border-color: var(--accent-line);
  color: var(--accent);
}

.arrow {
  color: var(--muted);
}

.recent-list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.recent {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 8px;
  width: 100%;
  min-height: 40px;
  padding: 6px 10px;
  border: 0;
  border-radius: var(--radius-small);
  background: transparent;
  font-size: 0.9375rem;
  font-variant-numeric: tabular-nums;
  text-align: left;
  transition: background-color var(--speed) ease;
}

.recent:hover {
  background: rgba(148, 163, 184, 0.08);
}

.recent-from {
  color: var(--muted);
}

.recent-to {
  font-weight: 650;
}

.empty {
  color: var(--muted);
  font-size: 0.875rem;
}

/* ---------- All-units table ---------- */

.table-card {
  padding: 16px 10px 10px;
}

.table-card .card-head {
  padding: 0 4px 10px 6px;
}

.table-card .btn .icon {
  transition: transform var(--speed) ease;
}

.table-card .btn[aria-expanded="true"] .icon {
  transform: rotate(180deg);
}

.table-wrap {
  overflow-x: auto;
}

.unit-table {
  width: 100%;
  border-collapse: collapse;
}

.unit-table th,
.unit-table td {
  padding: 0;
  border-top: 1px solid var(--line);
  font-weight: 400;
  text-align: left;
  vertical-align: middle;
}

.unit-table tr:first-child > * {
  border-top: 0;
}

.unit-table tr.is-from,
.unit-table tr.is-to {
  background: var(--accent-soft);
}

/*
 * Phones get slightly smaller table text so the longest numbers
 * ("151,200,000,000,000", "−1.234567891 × 10⁻¹⁹") fit next to long Turkish
 * unit names at 360 px; wider screens go back to 16 px below.
 */
.unit-name {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 2px 8px;
  width: 100%;
  min-height: 40px;
  padding: 8px 4px 8px 8px;
  border: 0;
  border-radius: 8px;
  background: none;
  font-size: 0.9375rem;
  text-align: left;
}

.unit-name .name {
  transition: color var(--speed) ease;
}

.unit-name:hover .name {
  color: var(--accent);
}

.sym {
  color: var(--muted);
  font-size: 0.8125rem;
}

.tag {
  align-self: center;
  padding: 0 7px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.6;
  text-transform: uppercase;
}

.tag-from {
  background: transparent;
  color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent-line);
}

.unit-table td.num {
  padding: 0 2px 0 6px;
  font-size: 0.875rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  text-align: right;
  white-space: nowrap;
}

.unit-table tr.is-to td.num {
  color: var(--accent);
}

.unit-table td.copy-cell {
  width: 44px;
  text-align: right;
}

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 20px;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--text);
  color: var(--bg);
  font-size: 0.9375rem;
  font-weight: 650;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 12px);
  transition:
    opacity var(--speed) ease,
    transform var(--speed) ease;
}

.toast .icon {
  width: 18px;
  height: 18px;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

.toast.is-error {
  background: var(--danger);
}

/* ---------- Wider screens ---------- */

@media (hover: hover) and (pointer: fine) {
  .kbd-hints {
    display: flex;
  }
}

@media (min-width: 480px) {
  .unit-name {
    padding: 8px 6px 8px 10px;
    font-size: 1rem;
  }

  .unit-table td.num {
    padding: 0 4px 0 8px;
    font-size: 1rem;
  }
}

@media (min-width: 640px) {
  .tagline {
    display: block;
  }

  .pair {
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    align-items: center;
    gap: 10px;
  }

  .swap {
    margin: 0;
    box-shadow: none;
  }

  .swap .icon {
    transform: rotate(var(--turns, 0deg));
  }

  .amount {
    font-size: 1.5rem;
  }

  .lists {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 24px;
  }
}

@media (min-width: 960px) {
  .app {
    padding: 0 24px 16px;
  }

  .chips-wrap {
    margin: 0;
  }

  .chips {
    flex-wrap: wrap;
    gap: 6px;
    overflow: visible;
    padding: 4px 0 8px;
    -webkit-mask-image: none;
    mask-image: none;
  }

  .chip {
    padding: 0 12px;
  }

  .layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: 20px;
  }
}

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