:root {
  --ink: #10253a;
  --muted: #5d6774;
  --accent: #c8612b;
  --accent-soft: rgba(198, 97, 43, 0.12);
  --teal: #1d6b78;
  --line: rgba(16, 37, 58, 0.12);
  --line-strong: rgba(16, 37, 58, 0.22);
  --paper: rgba(255, 252, 247, 0.95);
  --panel: rgba(248, 242, 233, 0.92);
  --panel-strong: rgba(242, 236, 228, 0.98);
  --shadow: 0 22px 48px rgba(16, 37, 58, 0.09);
  --radius: 22px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "IBM Plex Sans", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(198, 97, 43, 0.16), transparent 32%),
    radial-gradient(circle at bottom right, rgba(29, 107, 120, 0.14), transparent 28%),
    linear-gradient(140deg, #f5efe3 0%, #fffdf8 46%, #e7eef1 100%);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(16, 37, 58, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(16, 37, 58, 0.04) 1px, transparent 1px);
  background-size: 30px 30px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 90%);
}

a {
  color: inherit;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  appearance: none;
  border: none;
  cursor: pointer;
}

#app {
  position: relative;
  z-index: 1;
}

.page-shell {
  max-width: 1680px;
  margin: 0 auto;
  padding: 28px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) auto minmax(280px, 420px);
  gap: 22px;
  align-items: end;
  padding: 26px 28px;
  border: 1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  background:
    linear-gradient(180deg, rgba(255, 252, 247, 0.94), rgba(255, 252, 247, 0.86)),
    linear-gradient(120deg, rgba(198, 97, 43, 0.08), rgba(29, 107, 120, 0.06));
  box-shadow: var(--shadow);
}

.eyebrow,
.panel-kicker {
  margin: 0 0 8px;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.74rem;
  font-weight: 700;
}

h1,
h2,
h3,
h4,
summary {
  font-family: "Fraunces", serif;
}

h1 {
  margin: 0;
  font-size: clamp(2.5rem, 4vw, 4rem);
  line-height: 0.94;
}

.hero__copy {
  max-width: 780px;
  margin: 12px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: end;
}

.action-button {
  padding: 0.86rem 1.18rem;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(255, 252, 247, 0.74);
  color: var(--ink);
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    border-color 160ms ease;
}

.action-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 22px rgba(16, 37, 58, 0.08);
}

.action-button--primary {
  background: linear-gradient(135deg, #c8612b, #df8151);
  border-color: transparent;
  color: #fffdf9;
  box-shadow: 0 12px 26px rgba(198, 97, 43, 0.24);
}

.hero__status {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.workflow-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 18px 0 24px;
}

.workflow-nav a {
  padding: 0.72rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 252, 247, 0.88);
  text-decoration: none;
  font-size: 0.92rem;
  color: var(--muted);
}

.top-workflow-grid {
  display: grid;
  grid-template-columns: minmax(280px, 360px) minmax(360px, 520px) minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}

.top-input-stack,
.workspace,
.top-figure-column {
  display: flex;
  flex-direction: column;
  gap: 18px;
  min-width: 0;
}

.panel,
.subpanel,
.metric-card,
.step-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: var(--shadow);
}

.panel,
.subpanel {
  padding: 18px;
}

details.panel,
details.subpanel {
  padding: 0;
  overflow: hidden;
}

.accordion-summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 18px;
  user-select: none;
}

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

.accordion-copy p:last-child {
  margin-bottom: 0;
}

.accordion-copy h2 {
  margin: 0 0 4px;
}

.accordion-copy p {
  margin: 0;
  color: var(--muted);
}

.accordion-chevron {
  margin-left: auto;
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--muted);
  border-bottom: 2px solid var(--muted);
  transform: rotate(45deg);
  transition: transform 180ms ease;
}

details[open] > summary .accordion-chevron {
  transform: rotate(225deg);
}

.accordion-body {
  padding: 0 18px 18px;
}

.panel-head,
.panel-head--compact {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
}

.panel-head h2,
.panel-head h3,
.subpanel h3 {
  margin: 0;
}

.panel-head p,
.subpanel p {
  margin: 0;
}

.field-grid {
  display: grid;
  gap: 14px;
}

.field-grid--two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.field-grid--three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.field {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.field span {
  font-weight: 600;
  color: var(--ink);
}

.field small {
  color: var(--muted);
  line-height: 1.4;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  border-radius: 14px;
  border: 1px solid var(--line-strong);
  padding: 0.82rem 0.94rem;
  background: rgba(255, 255, 255, 0.84);
  color: var(--ink);
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: 2px solid rgba(198, 97, 43, 0.18);
  border-color: rgba(198, 97, 43, 0.32);
}

.field--wide {
  grid-column: 1 / -1;
}

.field--checkbox {
  justify-content: end;
}

.field--checkbox input {
  width: 20px;
  height: 20px;
  padding: 0;
}

.logo-uploader {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 16px;
  margin-top: 18px;
}

.logo-preview {
  min-height: 110px;
  border-radius: 18px;
  border: 1px dashed var(--line-strong);
  background: rgba(255, 255, 255, 0.82);
  display: grid;
  place-items: center;
  overflow: hidden;
  color: var(--muted);
}

.logo-preview img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  padding: 12px;
}

.logo-uploader__controls {
  display: grid;
  gap: 10px;
  align-content: start;
}

.action-button--file {
  width: fit-content;
}

.action-button--small {
  padding: 0.58rem 0.86rem;
  font-size: 0.84rem;
}

.action-button--danger {
  border-color: rgba(177, 55, 30, 0.22);
  color: #8f2c19;
}

.derived-strip,
.metric-grid,
.dashboard-grid {
  display: grid;
  gap: 14px;
}

.derived-strip,
.metric-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

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

.derived-strip--tall {
  align-items: stretch;
}

.metric-card {
  padding: 16px;
  background:
    linear-gradient(180deg, rgba(255, 252, 247, 0.98), rgba(248, 242, 233, 0.98)),
    linear-gradient(115deg, rgba(198, 97, 43, 0.06), rgba(29, 107, 120, 0.04));
}

.metric-card__label {
  margin: 0 0 10px;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.metric-card__value {
  font-size: 1.55rem;
  font-weight: 700;
}

.metric-card__note {
  margin: 8px 0 0;
  color: var(--muted);
  line-height: 1.45;
}

.message-stack,
.assumption-list,
.equation-stack,
.report-outline,
.step-stack,
.layer-editor__rows,
.layer-editor-stack {
  display: grid;
  gap: 12px;
}

.message-card {
  padding: 14px 16px;
  border-radius: 16px;
  border: 1px solid var(--line);
  line-height: 1.5;
}

.message-card--info {
  background: rgba(29, 107, 120, 0.08);
}

.message-card--warning {
  background: rgba(198, 97, 43, 0.1);
}

.message-card--error {
  background: rgba(177, 55, 30, 0.1);
}

.assumption-pill {
  padding: 12px 14px;
  border-radius: 999px;
  background: rgba(255, 252, 247, 0.84);
  border: 1px solid var(--line);
}

.analysis-grid,
.report-preview-grid,
.steps-grid {
  display: grid;
  gap: 18px;
}

.analysis-grid,
.report-preview-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

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

.equation-stack .equation-block,
.equation-note {
  margin: 0;
}

.equation-note {
  color: var(--muted);
  line-height: 1.6;
}

.equation-block {
  padding: 14px 16px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.84);
  border: 1px solid rgba(16, 37, 58, 0.08);
  overflow-x: auto;
}

.equation-inline {
  display: inline-flex;
  margin: 0 4px;
}

.kv-grid {
  display: grid;
  gap: 10px;
}

.kv-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.kv-row span {
  color: var(--muted);
}

.drawing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.drawing-card {
  padding: 16px;
  border-radius: var(--radius);
  background: rgba(255, 252, 247, 0.94);
  border: 1px solid var(--line);
}

.drawing-card h3 {
  margin: 0 0 12px;
}

.diagram-panel {
  fill: rgba(255, 255, 255, 0.78);
  stroke: rgba(16, 37, 58, 0.1);
}

.drawing-card svg,
.figure-panel svg {
  display: block;
  width: 100%;
  height: auto;
}

.step-card {
  display: grid;
  grid-template-columns: 70px minmax(0, 1fr);
  gap: 14px;
  padding: 16px;
}

.step-card--detail {
  align-items: start;
}

.step-card__index {
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: linear-gradient(145deg, rgba(198, 97, 43, 0.18), rgba(29, 107, 120, 0.12));
  font-size: 1.15rem;
  font-weight: 700;
}

.step-card__body h4 {
  margin: 0 0 12px;
}

.step-card__narrative {
  margin: 0 0 12px;
  color: var(--muted);
  line-height: 1.55;
}

.report-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 18px;
}

.report-outline div {
  padding: 12px 14px;
  border-radius: 16px;
  background: rgba(248, 242, 233, 0.92);
}

.workspace-panel {
  scroll-margin-top: 24px;
}

.figure-panel {
  overflow: hidden;
}

.layer-schedule-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.layer-schedule-table {
  display: grid;
  gap: 10px;
}

.layer-schedule-row {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) 100px 120px;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  align-items: center;
}

.layer-editor {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(255, 252, 247, 0.88);
}

.layer-editor__header {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: start;
  margin-bottom: 14px;
}

.layer-editor__header h3 {
  margin: 0 0 4px;
}

.layer-editor__header p {
  margin: 0;
  color: var(--muted);
}

.layer-row {
  display: grid;
  gap: 12px;
  padding: 14px;
  border-radius: 16px;
  background: rgba(248, 242, 233, 0.96);
  border: 1px solid rgba(16, 37, 58, 0.08);
}

.layer-row__title {
  font: 600 0.9rem "IBM Plex Mono", monospace;
  color: var(--muted);
}

.layer-row__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
}

.layer-row__derived {
  padding: 0.82rem 0.94rem;
  border-radius: 14px;
  border: 1px solid rgba(16, 37, 58, 0.08);
  background: rgba(255, 255, 255, 0.76);
  display: grid;
  gap: 4px;
}

.layer-row__derived span {
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.empty-state {
  padding: 14px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.7);
  color: var(--muted);
  border: 1px dashed var(--line);
}

.section-outline {
  fill: none;
  stroke: #132740;
  stroke-width: 2.2;
}

.section-fill {
  fill: rgba(29, 107, 120, 0.08);
}

.compression-block {
  fill: rgba(198, 97, 43, 0.18);
  stroke: rgba(198, 97, 43, 0.45);
  stroke-width: 1.4;
}

.bar {
  stroke: #10253a;
  stroke-width: 1.6;
}

.bar--bottom {
  fill: rgba(29, 107, 120, 0.78);
}

.bar--top {
  fill: rgba(198, 97, 43, 0.74);
}

.stirrup-outline {
  fill: none;
  stroke: #1d6b78;
  stroke-width: 2.1;
}

.stirrup-hook {
  fill: none;
  stroke: #1d6b78;
  stroke-width: 2.1;
}

.neutral-axis,
.effective-depth-line,
.stress-axis,
.lever-arm-line,
.force-arrow,
.dim-arrow,
.dim-extension,
.callout-line,
.shear-crack {
  stroke: #10253a;
  stroke-width: 1.8;
  fill: none;
}

.neutral-axis {
  stroke: #1d6b78;
  stroke-dasharray: 7 6;
}

.effective-depth-line {
  stroke: #c8612b;
  stroke-dasharray: 6 4;
}

.lever-arm-line,
.lever-arm-cap {
  stroke: #c8612b;
  stroke-width: 1.8;
}

.force-arrow--compression {
  color: #c8612b;
}

.force-arrow--tension {
  color: #1d6b78;
}

.dim-arrow {
  stroke: rgba(16, 37, 58, 0.56);
}

.dim-extension,
.callout-line {
  stroke: rgba(16, 37, 58, 0.34);
  stroke-width: 1.3;
}

.panel-divider {
  stroke: rgba(16, 37, 58, 0.12);
  stroke-width: 1.2;
}

.shear-crack {
  stroke: #c8612b;
  stroke-width: 2.4;
  stroke-dasharray: 8 6;
}

.drawing-frame {
  fill: rgba(255, 255, 255, 0.72);
  stroke: rgba(16, 37, 58, 0.12);
}

.drawing-title {
  font: 700 17px "IBM Plex Sans", sans-serif;
  fill: #10253a;
}

.drawing-subtitle,
.drawing-panel-title {
  font: 500 12px "IBM Plex Mono", monospace;
  fill: #58697b;
}

.drawing-label,
.dim-text,
.drawing-note {
  font: 500 13px "IBM Plex Mono", monospace;
  fill: #37495b;
}

.dim-text--center {
  text-anchor: middle;
}

.drawing-note {
  font-size: 12px;
}

.info-box {
  fill: rgba(248, 242, 233, 0.96);
  stroke: rgba(16, 37, 58, 0.12);
}

.rebar-line {
  stroke-width: 3;
}

.rebar-line--top {
  stroke: rgba(198, 97, 43, 0.78);
}

.rebar-line--bottom {
  stroke: rgba(29, 107, 120, 0.82);
}

.strain-profile {
  fill: rgba(29, 107, 120, 0.14);
  stroke: rgba(29, 107, 120, 0.82);
  stroke-width: 2;
}

.steel-stress-line {
  stroke-width: 2.2;
}

.steel-stress-line--compression {
  stroke: rgba(198, 97, 43, 0.8);
  color: rgba(198, 97, 43, 0.8);
}

.steel-stress-line--tension {
  stroke: rgba(29, 107, 120, 0.9);
  color: rgba(29, 107, 120, 0.9);
}

.report-preview-grid .subpanel,
.analysis-grid .subpanel {
  background: var(--panel-strong);
}

@media (max-width: 1280px) {
  .hero {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .hero__actions {
    justify-content: start;
  }

  .hero__status,
  .derived-strip,
  .metric-grid,
  .dashboard-grid,
  .analysis-grid,
  .report-preview-grid,
  .steps-grid,
  .layer-schedule-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .top-workflow-grid {
    grid-template-columns: minmax(320px, 420px) minmax(0, 1fr);
  }

  .top-input-stack--primary {
    grid-column: 1;
    grid-row: 1;
  }

  .top-input-stack--secondary {
    grid-column: 1;
    grid-row: 2;
  }

  .top-figure-column {
    grid-column: 2;
    grid-row: 1 / span 2;
  }
}

@media (max-width: 760px) {
  .page-shell {
    padding: 18px;
  }

  .hero,
  .panel,
  .subpanel {
    border-radius: 18px;
  }

  .field-grid--two,
  .field-grid--three,
  .hero__status,
  .derived-strip,
  .metric-grid,
  .dashboard-grid,
  .analysis-grid,
  .report-preview-grid,
  .steps-grid,
  .layer-schedule-grid {
    grid-template-columns: 1fr;
  }

  .step-card {
    grid-template-columns: 1fr;
  }

  .logo-uploader,
  .layer-row__grid,
  .layer-schedule-row {
    grid-template-columns: 1fr;
  }

  .workflow-nav {
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .top-workflow-grid {
    grid-template-columns: 1fr;
  }

  .top-input-stack--primary,
  .top-input-stack--secondary,
  .top-figure-column {
    grid-column: auto;
    grid-row: auto;
  }
}