:root {
  --primary: #1a73e8;
  --primary-hover: #1557b0;
  --primary-light: #e8f0fe;
  --bg-color: #f8fafc;
  --card-bg: #ffffff;
  --text-main: #202124;
  --text-muted: #5f6368;
  --text-sub: #80868b;
  --border-color: #dadce0;
  --border-light: #edf2f7;
  --success: #1e8e3e;
  --danger: #d93025;
  --danger-light: #fce8e6;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(60, 64, 67, 0.08);
  --shadow-md: 0 4px 12px rgba(60, 64, 67, 0.1);
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  padding: 30px 20px;
  min-height: 100vh;
}

.app-container {
  max-width: 820px;
  margin: 0 auto;
}

/* Header */
.app-header {
  margin-bottom: 24px;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 20px;
}

.logo-icon {
  width: 100px;
  height: 100px;
  flex: 0 0 auto;
  object-fit: contain;
}

.logo-area h1 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.3px;
}

.subtitle {
  font-size: 13.5px;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Tabs */
.tabs-nav {
  display: flex;
  gap: 8px;
  background-color: #ebedf0;
  padding: 4px;
  border-radius: var(--radius-md);
  width: fit-content;
}

.tab-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: none;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  color: var(--text-main);
}

.tab-btn.active {
  background-color: var(--card-bg);
  color: var(--primary);
  box-shadow: var(--shadow-sm);
}

/* Card */
.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* Input Area */
.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 10px;
}

.input-title {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-main);
}

.quick-tags {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.quick-chip {
  background: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s ease;
}

.quick-chip:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: #c2e7ff;
}

.quick-chip.clear {
  color: var(--danger);
  border-color: #f8d7da;
}

.quick-chip.clear:hover {
  background: var(--danger-light);
}

.input-group {
  position: relative;
  display: flex;
  align-items: center;
}

.input-group input {
  width: 100%;
  padding: 16px 65px 16px 18px;
  font-size: 28px;
  font-weight: 700;
  font-family: inherit;
  color: var(--text-main);
  background: #fdfdfd;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  letter-spacing: 0.5px;
}

.input-group input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
  background: #fff;
}

.currency-suffix {
  position: absolute;
  right: 18px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-sub);
  pointer-events: none;
}

/* Options */
.options-bar {
  display: flex;
  gap: 24px;
  margin-top: 18px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.custom-checkbox {
  display: flex;
  align-items: center;
  position: relative;
  font-size: 13.5px;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
  gap: 8px;
}

.custom-checkbox input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}

.checkmark {
  width: 18px;
  height: 18px;
  background-color: #fff;
  border: 2px solid var(--border-color);
  border-radius: 4px;
  display: inline-block;
  position: relative;
  transition: all 0.15s ease;
}

.custom-checkbox input:checked~.checkmark {
  background-color: var(--primary);
  border-color: var(--primary);
}

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
  left: 5px;
  top: 2px;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.custom-checkbox input:checked~.checkmark:after {
  display: block;
}

/* Result Box */
.result-box {
  background: #f8fafd;
  border: 1px solid #d2e3fc;
  border-radius: var(--radius-md);
  padding: 20px;
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.result-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.btn-copy {
  display: flex;
  align-items: center;
  gap: 6px;
  background: #ffffff;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  font-family: inherit;
}

.btn-copy:hover {
  background: var(--primary-light);
  color: var(--primary);
  border-color: #c2e7ff;
}

.result-text {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.6;
  min-height: 60px;
  display: flex;
  align-items: center;
  word-break: break-word;
}

.result-actions {
  margin-top: 14px;
  display: flex;
  justify-content: flex-end;
}

/* Calculator Tab */
.calc-intro {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
  gap: 16px;
  flex-wrap: wrap;
}

.calc-intro h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 4px;
}

.calc-form {
  margin-bottom: 24px;
}

.calc-form-fields {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.field-desc {
  flex: 1;
  min-width: 220px;
}

.field-expr {
  flex: 1.2;
  min-width: 240px;
}

.calc-form input {
  width: 100%;
  padding: 12px 14px;
  font-size: 14.5px;
  font-family: inherit;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.15s;
}

.calc-form input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.15);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-secondary:hover {
  background: #f1f3f4;
}

.btn-sm {
  padding: 6px 12px;
  font-size: 12.5px;
}

.btn-xs {
  padding: 4px 8px;
  font-size: 11.5px;
}

.text-danger {
  color: var(--danger) !important;
}

.text-danger:hover {
  background: var(--danger-light) !important;
}

.calc-hints {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 6px;
}

.calc-table-wrap {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin-bottom: 20px;
  background: #fff;
}

.calc-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
}

.calc-table th {
  background: #f8fafc;
  padding: 12px 14px;
  text-align: left;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
}

.calc-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-main);
}

.calc-table tr:last-child td {
  border-bottom: none;
}

.text-right {
  text-align: right;
}

.text-center {
  text-align: center;
}

.amount-col {
  font-weight: 700;
  color: #1a73e8;
}

.btn-action-del {
  background: transparent;
  border: none;
  color: #9aa0a6;
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  transition: color 0.15s;
}

.btn-action-del:hover {
  color: var(--danger);
  background: var(--danger-light);
}

.empty-state {
  padding: 30px;
  text-align: center;
  color: var(--text-sub);
  font-size: 13.5px;
}

/* Summary Card */
.calc-summary-card {
  background: #f8fafd;
  border: 1px solid #d2e3fc;
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.summary-info {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-bottom: 1px dashed #c2e7ff;
  padding-bottom: 12px;
  flex-wrap: wrap;
  gap: 8px;
}

.summary-count {
  font-size: 13px;
  color: var(--text-muted);
  background: #e8f0fe;
  padding: 2px 8px;
  border-radius: 12px;
  font-weight: 600;
}

.summary-total-label {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-muted);
}

.summary-total-number {
  font-size: 28px;
  font-weight: 800;
  color: #1a73e8;
  letter-spacing: -0.5px;
}

.summary-words-box {
  background: #ffffff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 14px;
}

.summary-words-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 12.5px;
  color: var(--text-muted);
  font-weight: 600;
}

.summary-words-text {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.5;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background-color: #202124;
  color: #ffffff;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: all 0.25s ease;
  z-index: 9999;
}

.toast.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 600px) {
  body {
    padding: 16px 12px;
  }

  .card {
    padding: 18px 14px;
  }

  .input-group input {
    font-size: 22px;
    padding: 12px 55px 12px 14px;
  }

  .result-text {
    font-size: 17px;
  }

  .summary-total-number {
    font-size: 22px;
  }
}