:root {
  --bg-dark: #0a0f16;
  --bg-panel: #0f1620;
  --bg-card: #131c27;
  --bg-input: #0b1119;
  --border: #223142;
  --border-active: #355b7a;
  --text: #e9eef5;
  --text-dim: #88a0b5;
  --text-label: #6f869a;
  --accent: #00b4d8;
  --accent-soft: rgba(0, 180, 216, 0.15);
  --warn: #ffc857;
  --danger: #ff5d5d;
  --ok: #00d68f;
  --blue: #4a9eff;
  --cyan: #00e5ff;
  --amber: #ffc857;
  --red: #ff5d5d;
  --purple: #b58cff;
  --green: #00d68f;
}

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

html, body {
  min-height: 100%;
}

body {
  font-family: "Rajdhani", sans-serif;
  background: radial-gradient(circle at 15% 5%, rgba(0, 180, 216, 0.1) 0%, transparent 32%), var(--bg-dark);
  color: var(--text);
}

.grid-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(rgba(0, 180, 216, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 180, 216, 0.035) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.app {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(180deg, rgba(0, 180, 216, 0.08), rgba(0, 180, 216, 0));
  padding: 16px 22px;
}

.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  color: var(--accent);
  filter: drop-shadow(0 0 8px rgba(0, 180, 216, 0.45));
}

h1 {
  font-size: 28px;
  letter-spacing: 0.14em;
  color: var(--accent);
  line-height: 1;
}

.logo-wrap p {
  font-size: 10px;
  letter-spacing: 0.24em;
  color: var(--text-dim);
}

.header-actions {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.header-badges {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.badge {
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-dim);
  font-size: 11px;
  letter-spacing: 0.08em;
  font-weight: 600;
  padding: 7px 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 8px rgba(0, 180, 216, 0.8);
}

.dot.warn {
  background: var(--warn);
  box-shadow: 0 0 8px rgba(255, 200, 87, 0.7);
}

.btn-pdf, .btn-reset {
  border: 1px solid var(--accent);
  background: linear-gradient(180deg, rgba(0, 180, 216, 0.22), rgba(0, 180, 216, 0.08));
  color: var(--accent);
  padding: 8px 16px;
  font-size: 11px;
  letter-spacing: 0.12em;
  font-weight: 700;
  cursor: pointer;
  text-transform: uppercase;
  transition: all 0.2s ease;
  font-family: "Rajdhani", sans-serif;
}

.btn-pdf:hover, .btn-reset:hover {
  box-shadow: 0 0 16px var(--accent-soft);
}

/* Tab Bar */
.tab-bar {
  display: inline-flex;
  width: fit-content;
  border: 1px solid var(--border);
  background: var(--bg-input);
  margin-bottom: 4px;
}

.tab-btn {
  border: 0;
  border-right: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  font-family: "Rajdhani", sans-serif;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  padding: 10px 18px;
  text-transform: uppercase;
  cursor: pointer;
}

.tab-btn:last-child {
  border-right: 0;
}

.tab-btn.active {
  background: linear-gradient(180deg, rgba(0, 180, 216, 0.24), rgba(0, 180, 216, 0.08));
  color: var(--accent);
}

.tab-content {
  display: none;
  flex-direction: column;
  gap: 16px;
}

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

/* Main layout */
.main {
  display: grid;
  grid-template-columns: minmax(320px, 400px) 1fr;
  min-height: calc(100vh - 90px);
}

.panel {
  padding: 20px;
}

.inputs-panel {
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  overflow-y: auto;
}

.results-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 20px;
}

.panel-title {
  font-size: 12px;
  letter-spacing: 0.18em;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 12px;
}

/* Input cards (details/summary pattern from HeatFlow) */
.card {
  position: relative;
  background: linear-gradient(180deg, rgba(19, 28, 39, 0.96), rgba(14, 21, 30, 0.96));
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px;
  margin-bottom: 12px;
}

.card summary {
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
  padding-left: 14px;
  position: relative;
  list-style: none;
}

.card summary::-webkit-details-marker {
  display: none;
}

.card summary::before {
  content: "\25B8";
  position: absolute;
  left: 0;
  color: var(--text-dim);
  transition: transform 0.2s;
}

.card[open] summary::before {
  transform: rotate(90deg);
}

.card.amber { border-left: 3px solid var(--amber); }
.card.blue { border-left: 3px solid var(--blue); }
.card.cyan { border-left: 3px solid var(--cyan); }
.card.red { border-left: 3px solid var(--red); }
.card.purple { border-left: 3px solid var(--purple); }
.card.green { border-left: 3px solid var(--green); }
.card.warn { border-left: 3px solid var(--warn); }
.card.dim { border-left: 3px solid var(--text-label); }

.card-body {
  margin-top: 12px;
}

/* Form fields */
.field {
  margin-bottom: 14px;
}

label {
  display: block;
  font-size: 10px;
  letter-spacing: 0.15em;
  color: var(--text-label);
  margin-bottom: 5px;
  text-transform: uppercase;
}

input, select {
  width: 100%;
  border: 1px solid var(--border);
  background: var(--bg-input);
  color: var(--text);
  font-family: "JetBrains Mono", monospace;
  font-size: 13px;
  padding: 10px 12px;
  outline: none;
  border-radius: 4px;
}

input:focus, select:focus {
  border-color: var(--border-active);
  box-shadow: 0 0 0 2px rgba(53, 91, 122, 0.22);
}

input:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.input-wrap {
  position: relative;
}

.unit {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-family: "JetBrains Mono", monospace;
  font-size: 11px;
  color: var(--text-dim);
  pointer-events: none;
}

.meta {
  font-size: 11px;
  color: var(--text-dim);
  margin-top: 5px;
  font-family: "JetBrains Mono", monospace;
}

.grid-two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.radio-group {
  display: flex;
  gap: 8px;
}

.radio-group label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  text-transform: none;
  letter-spacing: 0.02em;
  color: var(--text);
  cursor: pointer;
}

.radio-group input[type="radio"] {
  width: auto;
  accent-color: var(--accent);
}

/* Dynamic rows */
.row-head {
  display: grid;
  gap: 6px;
  font-size: 9px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-label);
  padding: 0 0 4px 0;
  margin-bottom: 4px;
}

.dynamic-row {
  display: grid;
  gap: 6px;
  align-items: center;
  padding: 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--bg-input);
  margin-bottom: 6px;
}

.dynamic-row select,
.dynamic-row input {
  padding: 7px 8px;
  font-size: 12px;
}

.btn-remove {
  background: transparent;
  border: 1px solid var(--danger);
  color: var(--danger);
  padding: 5px 8px;
  font-size: 10px;
  cursor: pointer;
  border-radius: 4px;
  font-family: "Rajdhani", sans-serif;
  font-weight: 700;
  letter-spacing: 0.05em;
  transition: all 0.2s;
}

.btn-remove:hover {
  background: rgba(255, 93, 93, 0.15);
}

.btn-add {
  border: 1px dashed var(--border-active);
  background: transparent;
  color: var(--text-dim);
  padding: 8px 12px;
  font-size: 12px;
  letter-spacing: 0.08em;
  font-weight: 600;
  cursor: pointer;
  border-radius: 4px;
  font-family: "Rajdhani", sans-serif;
  text-transform: uppercase;
  transition: all 0.2s;
  width: 100%;
  margin-top: 4px;
}

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

.btn-calc {
  width: 100%;
  border: 1px solid var(--accent);
  background: linear-gradient(180deg, rgba(0, 180, 216, 0.22), rgba(0, 180, 216, 0.08));
  color: var(--text);
  padding: 11px;
  font-size: 13px;
  letter-spacing: 0.12em;
  font-weight: 700;
  cursor: pointer;
  text-transform: uppercase;
  transition: all 0.2s ease;
  font-family: "Rajdhani", sans-serif;
  border-radius: 4px;
  margin-top: 8px;
}

.btn-calc:hover {
  box-shadow: 0 0 16px var(--accent-soft);
}

/* Results */
.hero-card {
  border: 1px solid var(--accent);
  background: linear-gradient(180deg, rgba(0, 180, 216, 0.12), rgba(0, 180, 216, 0.03));
  border-radius: 10px;
  padding: 20px;
}

.hero-card .eyebrow {
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.hero-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 16px;
}

.hero-grid > div {
  display: flex;
  flex-direction: column;
}

.hero-grid span {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.hero-grid strong {
  font-family: "JetBrains Mono", monospace;
  font-size: 28px;
  color: var(--text);
  font-weight: 600;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}

.result-card {
  border: 1px solid var(--border);
  background: var(--bg-card);
  padding: 14px;
  border-radius: 8px;
}

.result-card.emphasis {
  border-color: rgba(0, 180, 216, 0.5);
  box-shadow: inset 0 0 0 1px rgba(0, 180, 216, 0.15);
}

.result-card h3 {
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-label);
}

.result-card .value {
  margin-top: 8px;
  font-family: "JetBrains Mono", monospace;
  font-size: 24px;
  color: var(--text);
}

.result-card .sub {
  margin-top: 6px;
  font-size: 12px;
  color: var(--text-dim);
}

.mono {
  font-family: "JetBrains Mono", monospace;
  line-height: 1.45;
}

/* Tables */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
}

thead th {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-label);
  text-align: left;
  padding: 10px;
  border-bottom: 1px solid var(--border);
  text-transform: uppercase;
}

tbody td {
  font-family: "JetBrains Mono", monospace;
  font-size: 12px;
  color: var(--text);
  padding: 9px 10px;
  border-bottom: 1px solid rgba(34, 49, 66, 0.8);
}

tbody tr:hover {
  background: rgba(0, 180, 216, 0.06);
}

tbody tr.subtotal {
  font-weight: 700;
  background: rgba(0, 180, 216, 0.08);
}

tbody tr.recommended {
  font-weight: 700;
  background: rgba(0, 180, 216, 0.14);
  color: var(--accent);
}

/* Status indicators */
.status-pill {
  display: inline-block;
  border: 1px solid;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 10px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  font-weight: 700;
}

.status-pill.ok { color: var(--ok); border-color: rgba(0, 214, 143, 0.7); }
.status-pill.warn { color: var(--warn); border-color: rgba(255, 200, 87, 0.7); }
.status-pill.danger { color: var(--danger); border-color: rgba(255, 93, 93, 0.7); }

.notice {
  font-size: 12px;
  color: var(--text-dim);
  font-family: "JetBrains Mono", monospace;
  line-height: 1.5;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-card);
}

.notice.warn {
  border-color: var(--warn);
  color: var(--warn);
}

.notice.danger {
  border-color: var(--danger);
  color: var(--danger);
}

/* Method notes */
.method-notes {
  border: 1px solid var(--border);
  background: var(--bg-card);
  border-radius: 8px;
  padding: 16px;
}

.method-notes h2 {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  margin-bottom: 10px;
  text-transform: uppercase;
}

.method-notes ul {
  list-style: none;
  padding: 0;
}

.method-notes li {
  font-size: 12px;
  color: var(--text-dim);
  font-family: "JetBrains Mono", monospace;
  line-height: 1.6;
  padding-left: 14px;
  position: relative;
}

.method-notes li::before {
  content: "\203A";
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* Responsive */
@media (max-width: 1100px) {
  .main {
    grid-template-columns: 1fr;
  }
  .inputs-panel {
    border-right: 0;
    border-bottom: 1px solid var(--border);
  }
}

@media (max-width: 640px) {
  h1 { font-size: 22px; }
  .header { flex-direction: column; align-items: flex-start; }
  .panel { padding: 14px; }
  .grid-two { grid-template-columns: 1fr; }
  .hero-grid strong { font-size: 22px; }
}

/* Print */
@media print {
  .grid-bg, .tab-bar, .header-actions, .btn-calc, .btn-add, .btn-remove, .btn-pdf, .btn-reset {
    display: none !important;
  }
  .tab-content { display: flex !important; }
  .inputs-panel { border: 0; }
  body { background: white; color: black; }
  .card, .result-card, .hero-card, .method-notes, .table-wrap {
    border: 1px solid #999;
    background: white;
    color: black;
  }
  .hero-grid strong, .result-card .value, tbody td, .mono {
    color: black;
  }
}