/* XL Formula Generator — same design system as QR Creator / Unix timestamp */
:root {
  --bg: #0f0f12;
  --surface: #18181c;
  --border: #2a2a30;
  --text: #e4e4e7;
  --text-muted: #a1a1aa;
  --accent: #22c55e;
  --accent-hover: #4ade80;
  --error: #f87171;
  --radius: 12px;
  --font-sans: "DM Sans", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
}

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

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
}

.container {
  max-width: 700px;
  margin: 0 auto;
  padding: 2rem 1.25rem;
}

.header {
  text-align: center;
  margin-bottom: 2rem;
}

.header .title {
  font-size: 1.35rem;
  font-weight: 600;
  margin: 0 0 0.5rem;
}

.tagline {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
}

.formula-type-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.formula-type-title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.formula-type-actions {
  display: flex;
  gap: 0.5rem;
  flex-shrink: 0;
}

.formula-type-dropdown-row {
  width: 100%;
}

.formula-type-dropdown-row .dropdown {
  width: 100%;
  margin-bottom: 0;
}

.btn-mode {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--text-muted);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  transition: border-color 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.btn-mode:hover {
  border-color: var(--text-muted);
  color: var(--text);
}

.btn-mode[aria-pressed="true"] {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(34, 197, 94, 0.1);
}

.params-row-hidden {
  display: none;
}

.card-output-hidden {
  display: none;
}

.card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 1rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.hint {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin: 0 0 1rem;
}

.input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 0.75rem;
  transition: border-color 0.15s ease;
}

.input:focus {
  outline: none;
  border-color: var(--accent);
}

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

.input.mono {
  font-family: var(--font-mono);
}

/* Custom formula-type dropdown */
.dropdown-select {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.dropdown {
  position: relative;
  margin-bottom: 0.75rem;
}

.dropdown-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: border-color 0.15s ease, background 0.15s ease;
  text-align: left;
}

.dropdown-trigger:hover {
  border-color: var(--text-muted);
}

.dropdown-trigger[aria-expanded="true"] {
  border-color: var(--accent);
  outline: none;
}

.dropdown-value {
  flex: 1;
  min-width: 0;
}

.dropdown-arrow {
  flex-shrink: 0;
  width: 1.25rem;
  height: 1.25rem;
  margin-left: 0.5rem;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%23a1a1aa' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat center;
  background-size: 1.25rem;
  transition: transform 0.2s ease;
}

.dropdown-trigger[aria-expanded="true"] .dropdown-arrow {
  transform: rotate(180deg);
}

.dropdown-list {
  position: absolute;
  z-index: 10;
  top: calc(100% + 4px);
  left: 0;
  right: 0;
  margin: 0;
  padding: 0.25rem 0;
  list-style: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  max-height: 16rem;
  overflow-y: auto;
}

.dropdown-list[hidden] {
  display: none;
}

.dropdown-list li {
  padding: 0.6rem 1rem;
  font-size: 1rem;
  color: var(--text);
  cursor: pointer;
  transition: background 0.1s ease;
}

.dropdown-list li:hover {
  background: var(--border);
}

.dropdown-list li[aria-selected="true"] {
  background: rgba(34, 197, 94, 0.15);
  color: var(--accent);
}

.dropdown-list li:focus {
  outline: none;
  background: var(--border);
}

.label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.value-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.formula-output {
  flex: 1;
  min-width: 0;
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  word-break: break-all;
  color: var(--text);
}


.btn-copy {
  flex-shrink: 0;
  padding: 0.4rem 0.75rem;
  font-size: 0.8125rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--accent);
  background: transparent;
  border: 1px solid var(--accent);
  border-radius: 6px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  transition: background 0.15s ease, color 0.15s ease;
}

.btn-copy:hover:not(:disabled) {
  background: var(--accent);
  color: var(--bg);
}

.btn-copy:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-copy:active:not(:disabled) {
  transform: scale(0.98);
}

.btn-copy.copied {
  border-color: var(--accent);
  color: var(--accent);
}

.footer {
  text-align: center;
  padding-top: 2rem;
  margin-top: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Two cards: To (left) and From (right) */
.params-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
  align-items: stretch;
}

.params-card {
  flex: 1;
  min-width: 280px;
  margin-bottom: 0;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.params-card-title {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 0.25rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.params-hint {
  margin: 0 0 0.75rem;
  font-size: 0.8125rem;
}

#params-to-hint:empty,
#params-from-hint:empty {
  display: none;
  margin: 0;
}

#params-to-container,
#params-from-container {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.params-card-actions {
  margin-top: auto;
  padding-top: 0.75rem;
  display: flex;
  justify-content: flex-end;
}

.params-card-actions-left {
  justify-content: flex-start;
}

#params-to-container .label,
#params-from-container .label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
  margin-top: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

#params-to-container .label:first-child,
#params-from-container .label:first-child {
  margin-top: 0;
}

#params-to-container .input,
#params-from-container .input {
  width: 100%;
  margin-bottom: 0.75rem;
}

.params-block-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  margin: 1rem 0 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.params-block-label:first-child {
  margin-top: 0;
}

.btn-add-sheet {
  margin-top: 0.5rem;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--accent);
  background: transparent;
  border: 1px dashed var(--border);
  border-radius: 8px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  transition: border-color 0.15s ease, color 0.15s ease;
}

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

.btn-remove-sheet,
.btn-remove-key {
  margin-top: 0.25rem;
  margin-bottom: 0.75rem;
  padding: 0.35rem 0.6rem;
  font-size: 0.8125rem;
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  transition: border-color 0.15s ease, color 0.15s ease;
}

.btn-remove-sheet:hover,
.btn-remove-key:hover {
  color: var(--error);
  border-color: var(--error);
}