:root {
  --bg: #f4efe7;
  --bg-strong: #efe3d3;
  --panel: rgba(255, 252, 247, 0.78);
  --panel-border: rgba(125, 92, 58, 0.18);
  --ink: #1e2430;
  --muted: #5b6471;
  --teal: #0f766e;
  --blue: #1d4ed8;
  --orange: #b45309;
  --red: #b91c1c;
  --line: rgba(30, 36, 48, 0.08);
  --shadow: 0 24px 60px rgba(71, 53, 35, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Avenir Next", "Trebuchet MS", sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at top left, rgba(15, 118, 110, 0.18), transparent 26rem),
    radial-gradient(circle at top right, rgba(180, 83, 9, 0.16), transparent 24rem),
    linear-gradient(180deg, #fbf7f0 0%, #f3ede2 52%, #efe7dc 100%);
}

.page-shell {
  width: min(1400px, calc(100vw - 2rem));
  margin: 0 auto;
  padding: 0.7rem 0 1rem;
}

.app-header,
.panel {
  animation: rise 0.6s ease both;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.9rem;
  margin-bottom: 0.7rem;
}

.panel {
  border: 1px solid var(--panel-border);
  border-radius: 1.4rem;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px);
}

.panel {
  padding: 1rem 1.05rem;
}

.eyebrow {
  margin: 0 0 0.2rem;
  color: var(--orange);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  font-weight: 700;
}

h1,
h2 {
  margin: 0;
}

h1 {
  font-family: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
  font-size: clamp(1.3rem, 2vw, 1.8rem);
  line-height: 1;
  max-width: none;
}

.formula-label,
.metric-label {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-weight: 700;
  color: var(--muted);
}

.panel-header p,
.field small,
.message-box {
  color: var(--muted);
}

.tf-display {
  min-height: 3rem;
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
  font-size: clamp(0.84rem, 0.98vw, 1rem);
  line-height: 1.18;
  word-break: break-word;
}

.formula-stack {
  display: grid;
  gap: 0.72rem;
}

.equation-block {
  display: grid;
  gap: 0.28rem;
}

.formula-subtitle {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.equation {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink);
}

.equation-compact {
  gap: 0.42rem;
}

.equation-compact .equation-symbol {
  font-size: 0.98em;
}

.equation-tight {
  gap: 0.34rem;
}

.equation-tight .equation-main {
  gap: 0.28rem;
}

.equation-tight .fraction-num,
.equation-tight .fraction-den {
  padding: 0.02rem 0.3rem;
}

.equation-tight .factor-row {
  gap: 0.22rem;
}

.equation-tight .factor-chip {
  padding: 0.14rem 0.34rem;
  font-size: 0.76rem;
}

.equation-symbol {
  font-family: "Iowan Old Style", "Palatino Linotype", serif;
  font-size: 1.05em;
  font-style: italic;
  white-space: nowrap;
}

.equation-main {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  row-gap: 0.25rem;
  min-width: 0;
}

.equation-prefix {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.34rem;
}

.delay-term {
  font-family: "Iowan Old Style", "Palatino Linotype", serif;
  font-size: 0.98em;
  white-space: nowrap;
}

.fraction {
  display: inline-grid;
  grid-template-rows: auto auto auto;
  justify-items: center;
  width: fit-content;
  max-width: 100%;
  min-width: 0;
}

.fraction-num,
.fraction-den {
  text-align: center;
  padding: 0.04rem 0.45rem;
  font-family: "Iowan Old Style", "Palatino Linotype", serif;
  max-width: 100%;
  overflow-wrap: anywhere;
}

.fraction-bar {
  height: 1.2px;
  width: 100%;
  background: rgba(30, 36, 48, 0.88);
  border-radius: 999px;
  margin: 0.04rem 0;
}

.poly-formula {
  display: inline-block;
  white-space: normal;
  overflow-wrap: anywhere;
}

.factor-row {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 0.3rem;
  max-width: 100%;
}

.factor-chip {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.48rem;
  border-radius: 999px;
  border: 1px solid var(--factor-color);
  background: rgba(255, 255, 255, 0.92);
  color: var(--factor-color);
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
  font-size: 0.82rem;
  line-height: 1.25;
  white-space: nowrap;
}

.factor-neutral {
  border-color: rgba(30, 36, 48, 0.12);
  background: rgba(255, 255, 255, 0.8);
  color: var(--ink);
}

.gain-chip {
  border-color: rgba(15, 23, 42, 0.16);
  background: rgba(255, 255, 255, 0.84);
  color: var(--ink);
}

.factor-dot {
  color: var(--muted);
  font-size: 0.86rem;
}

.status-badge {
  align-self: flex-start;
  padding: 0.42rem 0.72rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  white-space: nowrap;
}

.status-valid {
  background: rgba(15, 118, 110, 0.12);
  color: var(--teal);
}

.status-error {
  background: rgba(185, 28, 28, 0.12);
  color: var(--red);
}

.app-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: 0.85rem;
}

.panel-full {
  grid-column: 1 / -1;
}

.panel-header {
  margin-bottom: 0.62rem;
}

.panel-header h2 {
  font-size: 1.08rem;
  margin-bottom: 0.18rem;
}

.panel-header p {
  margin: 0;
  line-height: 1.35;
  font-size: 0.88rem;
}

.field-grid {
  display: grid;
  gap: 0.78rem;
}

.field {
  display: grid;
  gap: 0.34rem;
}

.field span {
  font-weight: 700;
}

.field input {
  width: 100%;
  padding: 0.72rem 0.88rem;
  border-radius: 0.95rem;
  border: 1px solid rgba(30, 36, 48, 0.12);
  background: rgba(255, 255, 255, 0.9);
  font: inherit;
  color: var(--ink);
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.field input:focus {
  outline: none;
  border-color: rgba(15, 118, 110, 0.55);
  box-shadow: 0 0 0 4px rgba(15, 118, 110, 0.12);
  transform: translateY(-1px);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 0.8rem;
}

.button-row button {
  appearance: none;
  border: 0;
  border-radius: 999px;
  padding: 0.72rem 0.98rem;
  font: inherit;
  font-weight: 650;
  cursor: pointer;
  background: linear-gradient(135deg, #173c3b 0%, #0f766e 100%);
  color: #fff;
  box-shadow: 0 12px 20px rgba(15, 118, 110, 0.18);
  transition: transform 0.18s ease, box-shadow 0.18s ease, filter 0.18s ease;
}

.button-row button:nth-child(2) {
  background: linear-gradient(135deg, #2c3445 0%, #48566a 100%);
}

.button-row button:hover,
.button-row button:focus-visible {
  transform: translateY(-1px);
  filter: saturate(1.08);
}

.message-box {
  min-height: 1.3rem;
  margin-top: 0.7rem;
  line-height: 1.42;
  font-size: 0.88rem;
}

.message-box.error {
  color: var(--red);
}

.tf-card {
  margin-top: 0.75rem;
  padding: 0.7rem 0.8rem;
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.76);
  border: 1px solid rgba(30, 36, 48, 0.08);
}

.mono {
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
}

.metrics-content {
  display: grid;
  gap: 0.62rem;
}

.metrics-top,
.metrics-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.55rem;
}

.metric-card {
  padding: 0.62rem 0.68rem;
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--line);
}

.metric-value {
  margin-top: 0.24rem;
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
  font-size: 0.88rem;
  line-height: 1.34;
}

.metric-meta {
  margin-top: 0.14rem;
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.28;
}

.location-block {
  padding: 0.66rem 0.74rem;
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid var(--line);
}

.location-block .metric-label {
  margin-bottom: 0.28rem;
  display: block;
}

.location-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.38rem;
}

.plots-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.chip {
  padding: 0.34rem 0.56rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.86);
  border: 1px solid var(--line);
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
  font-size: 0.8rem;
}

.stability-stable {
  color: #16a34a;
}

.stability-marginal {
  color: #d97706;
}

.stability-unstable {
  color: #dc2626;
}

.corner-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
}

.corner-icon {
  font-weight: 700;
  font-size: 0.72rem;
}

.corner-pole {
  color: #dc2626;
}

.corner-zero {
  color: #16a34a;
}

.plot-readout {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 0 0 0.55rem;
}

.readout-pill {
  display: inline-flex;
  align-items: baseline;
  gap: 0.36rem;
  padding: 0.38rem 0.68rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.84);
  border: 1px solid rgba(30, 36, 48, 0.08);
  font-family: "SFMono-Regular", "Menlo", "Consolas", monospace;
  font-size: 0.84rem;
  color: var(--ink);
}

.readout-label {
  font-family: "Avenir Next", "Trebuchet MS", sans-serif;
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.plot {
  width: 100%;
  height: 600px;
  border-radius: 1rem;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(255, 255, 255, 0.56)),
    radial-gradient(circle at top right, rgba(15, 118, 110, 0.08), transparent 18rem);
  border: 1px solid rgba(30, 36, 48, 0.07);
}

.plot svg {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}

.plot-placeholder {
  height: 100%;
  display: grid;
  place-items: center;
  color: var(--muted);
  text-align: center;
  padding: 1.5rem;
}

@media (max-width: 1080px) {
  .app-grid {
    grid-template-columns: 1fr;
  }

  .metrics-top,
  .metrics-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .plots-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 680px) {
  .page-shell {
    width: calc(100vw - 0.75rem);
    padding-top: 0.4rem;
  }

  .app-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
  }

  h1 {
    font-size: 1.2rem;
  }

  .panel {
    border-radius: 1rem;
    padding: 0.75rem 0.8rem;
  }

  .panel-header h2 {
    font-size: 0.95rem;
  }

  .panel-header p {
    font-size: 0.8rem;
  }

  .field input {
    padding: 0.6rem 0.72rem;
    font-size: 0.9rem;
    border-radius: 0.75rem;
  }

  .field span {
    font-size: 0.85rem;
  }

  .field small {
    font-size: 0.72rem;
  }

  .button-row {
    gap: 0.45rem;
    margin-top: 0.6rem;
  }

  .button-row button {
    padding: 0.6rem 0.8rem;
    font-size: 0.85rem;
  }

  .plot {
    height: 520px;
    border-radius: 0.75rem;
  }

  .metrics-top,
  .metrics-row {
    grid-template-columns: 1fr 1fr;
    gap: 0.4rem;
  }

  .metric-card {
    padding: 0.5rem 0.55rem;
    border-radius: 0.75rem;
  }

  .metric-label {
    font-size: 0.68rem;
  }

  .metric-value {
    font-size: 0.78rem;
  }

  .tf-card {
    padding: 0.55rem 0.65rem;
    border-radius: 0.75rem;
  }

  .tf-display {
    font-size: 0.78rem;
    min-height: 2.4rem;
  }

  .equation {
    grid-template-columns: 1fr;
    gap: 0.3rem;
  }

  .equation-main {
    flex-wrap: wrap;
  }

  .factor-chip {
    padding: 0.14rem 0.34rem;
    font-size: 0.72rem;
  }

  .readout-pill {
    padding: 0.3rem 0.5rem;
    font-size: 0.76rem;
  }

  .readout-label {
    font-size: 0.68rem;
  }

  .plot-readout {
    gap: 0.38rem;
    margin-bottom: 0.4rem;
  }

  .chip {
    padding: 0.28rem 0.44rem;
    font-size: 0.72rem;
  }

  .location-block {
    padding: 0.5rem 0.6rem;
  }

  .message-box {
    font-size: 0.8rem;
    margin-top: 0.5rem;
  }

  .status-badge {
    padding: 0.32rem 0.58rem;
    font-size: 0.72rem;
  }
}

@media (max-width: 380px) {
  .page-shell {
    width: calc(100vw - 0.5rem);
  }

  .metrics-top,
  .metrics-row {
    grid-template-columns: 1fr;
  }

  .plot {
    height: 440px;
  }

  .button-row {
    flex-direction: column;
  }

  .button-row button {
    width: 100%;
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}