:root {
  color-scheme: dark;
  --bg: #101010;
  --bg-soft: #151515;
  --panel: #181818;
  --panel-strong: #202020;
  --plot-navy: #101a2a;
  --plot-navy-strong: #0b1421;
  --border: #3a3a3a;
  --border-strong: #5a5a5a;
  --text: #eeeeea;
  --muted: #aaa9a3;
  --quiet: #77766f;
  --accent: #eeeeea;
  --shadow: 0 22px 70px rgba(0, 0, 0, 0.32);
  --radius-panel: 8px;
  --radius-control: 5px;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  background:
    linear-gradient(180deg, #171717 0%, var(--bg) 42%, #0d0d0d 100%);
  color: var(--text);
}

button,
input {
  font: inherit;
}

.app-shell {
  width: min(1480px, calc(100% - 48px));
  margin: 0 auto;
  padding: 30px 0 56px;
}

.app-header {
  display: flex;
  justify-content: center;
  padding: 8px 0 24px;
  text-align: center;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 0;
  max-width: 980px;
  font-size: clamp(2.25rem, 5vw, 5.25rem);
  line-height: 0.95;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.control-form {
  display: grid;
  grid-template-columns: minmax(150px, 0.7fr) minmax(280px, 1.25fr) minmax(280px, 1.25fr) auto auto;
  grid-template-areas: "ticker strike dte smooth submit";
  gap: 12px;
  align-items: end;
  padding: 14px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  box-shadow: var(--shadow);
}

.field-group {
  display: grid;
  gap: 8px;
}

.ticker-field {
  grid-area: ticker;
}

.ticker-note {
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.4;
}

.control-form .range-control:first-of-type {
  grid-area: strike;
}

.control-form .range-control:nth-of-type(2) {
  grid-area: dte;
}

.toggle-row {
  grid-area: smooth;
}

.primary-button {
  grid-area: submit;
}

.field-group > span,
.field-heading > span,
.range-values span,
.surface-metric span,
.advanced-metric span {
  color: var(--muted);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.field-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
}

input[type="text"],
.range-number {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  background: #101010;
  color: var(--text);
  padding: 10px 12px;
}

input[type="text"]:focus,
.range-number:focus {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-color: var(--accent);
}

.range-values {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 6px;
  white-space: nowrap;
}

.range-number {
  width: 66px;
  min-height: 32px;
  padding: 5px 7px;
  text-align: center;
  color: var(--text);
  font-weight: 900;
  appearance: textfield;
}

.range-number::-webkit-outer-spin-button,
.range-number::-webkit-inner-spin-button {
  margin: 0;
  appearance: none;
}

.dual-range {
  position: relative;
  height: 34px;
  --thumb-size: 18px;
}

.range-track {
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 6px;
  transform: translateY(-50%);
  background: #2b2b2b;
  border: 1px solid #4a4a4a;
}

.range-fill {
  position: absolute;
  top: -1px;
  bottom: -1px;
  left: var(--range-min);
  right: calc(100% - var(--range-max));
  background: var(--accent);
}

.range-thumb {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 34px;
  margin: 0;
  appearance: none;
  pointer-events: none;
  background: transparent;
}

.range-thumb::-webkit-slider-runnable-track {
  height: 6px;
  background: transparent;
}

.range-thumb::-webkit-slider-thumb {
  width: var(--thumb-size);
  height: var(--thumb-size);
  margin-top: -6px;
  appearance: none;
  pointer-events: auto;
  cursor: grab;
  border: 2px solid #101010;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 1px #e6e3db;
}

.range-thumb::-moz-range-track {
  height: 6px;
  background: transparent;
}

.range-thumb::-moz-range-thumb {
  width: var(--thumb-size);
  height: var(--thumb-size);
  pointer-events: auto;
  cursor: grab;
  border: 2px solid #101010;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 1px #e6e3db;
}

.range-thumb:active::-webkit-slider-thumb,
.range-thumb:active::-moz-range-thumb {
  cursor: grabbing;
}

.toggle-row {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-control);
  color: var(--muted);
  background: #121212;
  cursor: pointer;
}

.toggle-row input {
  width: 17px;
  height: 17px;
  accent-color: var(--accent);
}

.toggle-row span {
  color: var(--text);
  font-family: inherit;
  font-size: 0.86rem;
  font-weight: 900;
  line-height: 1;
  text-transform: uppercase;
}

.primary-button {
  min-height: 42px;
  border: 1px solid var(--accent);
  border-radius: var(--radius-control);
  padding: 0 18px;
  color: #101010;
  background: var(--accent);
  cursor: pointer;
  font-size: 0.86rem;
  font-weight: 900;
  line-height: 1;
  text-transform: uppercase;
}

.primary-button:hover {
  background: #d8d5cd;
}

.primary-button:disabled {
  cursor: progress;
  opacity: 0.88;
}

.button-loading {
  display: none;
}

body.is-loading .button-ready {
  display: none;
}

body.is-loading .button-loading {
  display: inline;
}

.content-panel {
  display: grid;
  gap: 18px;
  padding-top: 18px;
}

.message-card,
.surface-card,
.advanced-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius-panel);
  box-shadow: var(--shadow);
}

.message-card {
  padding: 26px;
  background: var(--panel);
}

.message-card h2 {
  margin-bottom: 0;
  font-size: 1.2rem;
  text-transform: uppercase;
}

.error-card {
  border-color: #85817a;
}

.surface-card {
  padding: 18px;
  background: var(--plot-navy);
  border-color: #263448;
}

.surface-header {
  display: grid;
  grid-template-columns: minmax(160px, auto) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 2px 2px 16px;
}

.surface-header h2 {
  margin-bottom: 0;
  font-size: clamp(1.45rem, 2vw, 2.1rem);
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: uppercase;
}

.surface-metrics {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.surface-metric {
  display: grid;
  min-width: 128px;
  gap: 4px;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(238, 238, 234, 0.22);
  border-radius: var(--radius-control);
}

.surface-metric strong {
  font-size: 1.1rem;
  line-height: 1;
}

.plot-wrapper {
  position: relative;
  width: min(100%, 1160px);
  aspect-ratio: 4 / 3;
  margin: 0 auto;
  overflow: hidden;
  background: var(--plot-navy-strong);
  border: 1px solid #2b3b50;
  border-radius: var(--radius-control);
}

.plot-wrapper > div,
.plot-wrapper .plotly-graph-div {
  width: 100% !important;
  height: 100% !important;
}

.plot-loading-overlay,
.plot-loading-placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 16px;
  color: var(--text);
  background:
    radial-gradient(circle at center, rgba(238, 238, 234, 0.08), transparent 32%),
    rgba(11, 20, 33, 0.88);
  z-index: 6;
}

.plot-loading-overlay {
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.14s ease, visibility 0.14s ease;
}

body.is-loading .plot-loading-overlay {
  opacity: 1;
  visibility: visible;
}

.plot-loading-overlay p,
.plot-loading-placeholder p {
  margin: 0;
  color: var(--text);
  font-size: 0.84rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.loading-spinner {
  width: 54px;
  height: 54px;
  border: 3px solid rgba(238, 238, 234, 0.22);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: surface-spin 0.8s linear infinite;
}

.loading-surface-card {
  display: none;
}

body.is-loading .loading-surface-card {
  display: block;
}

body.is-loading.has-existing-surface .loading-surface-card {
  display: none;
}

body.is-loading .empty-card,
body.is-loading .error-card {
  display: none;
}

.loading-plot-shell {
  min-height: 520px;
}

@keyframes surface-spin {
  to {
    transform: rotate(360deg);
  }
}

.advanced-panel {
  background: var(--panel);
}

.advanced-panel summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 18px 20px;
  cursor: pointer;
  list-style: none;
}

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

.advanced-panel summary span {
  font-size: 1rem;
  font-weight: 900;
  text-transform: uppercase;
}

.advanced-panel summary small {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.advanced-panel summary::after {
  content: "+";
  display: inline-grid;
  place-items: center;
  width: 24px;
  height: 24px;
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  color: var(--text);
  font-weight: 900;
}

.advanced-panel[open] summary {
  border-bottom: 1px solid var(--border);
}

.advanced-panel[open] summary::after {
  content: "-";
}

.advanced-content {
  display: grid;
  gap: 16px;
  padding: 18px;
}

.advanced-metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 10px;
}

.advanced-metric,
.diagnostics-panel {
  border: 1px solid var(--border);
  background: var(--bg-soft);
  border-radius: var(--radius-control);
}

.advanced-metric {
  display: grid;
  gap: 6px;
  padding: 14px;
}

.advanced-metric strong {
  font-size: 1.18rem;
}

.diagnostics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 12px;
}

.diagnostics-panel {
  padding: 16px;
}

.diagnostics-panel h2 {
  margin-bottom: 12px;
  font-size: 0.95rem;
  text-transform: uppercase;
}

.diagnostics-panel ul {
  display: grid;
  gap: 8px;
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

@media (max-width: 1220px) {
  .control-form {
    grid-template-columns: minmax(0, 1fr) minmax(260px, 0.95fr);
    grid-template-areas:
      "ticker smooth"
      "dte smooth"
      "strike submit";
    align-items: stretch;
  }

  .ticker-field,
  .toggle-row,
  .primary-button {
    min-width: 0;
  }

  .toggle-row,
  .primary-button {
    width: 100%;
    min-height: 43px;
    align-self: end;
  }
}

@media (max-width: 820px) {
  .app-shell {
    width: min(100% - 24px, 1480px);
    padding-top: 18px;
  }

  .control-form {
    grid-template-columns: 1fr;
    grid-template-areas:
      "ticker"
      "dte"
      "strike"
      "smooth"
      "submit";
  }

  .field-heading,
  .surface-header,
  .advanced-panel summary {
    align-items: start;
    flex-direction: column;
  }

  .field-heading,
  .surface-header {
    display: grid;
    grid-template-columns: 1fr;
  }

  .range-values,
  .surface-metrics {
    justify-content: flex-start;
  }

  .plot-wrapper {
    width: 100%;
    aspect-ratio: 1 / 1;
    min-height: 420px;
  }
}