:root {
  color-scheme: light;
  --bg: #eef6ff;
  --bg-soft: #f8fbff;
  --card: rgba(255, 255, 255, 0.92);
  --card-solid: #ffffff;
  --text: #102033;
  --muted: #64748b;
  --muted-strong: #475569;
  --border: rgba(148, 163, 184, 0.28);
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-soft: #dbeafe;
  --accent: #0891b2;
  --good: #059669;
  --warning: #d97706;
  --danger: #dc2626;
  --shadow: 0 24px 70px rgba(15, 23, 42, 0.12);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #07111f;
  --bg-soft: #0f172a;
  --card: rgba(15, 23, 42, 0.86);
  --card-solid: #111c31;
  --text: #e5efff;
  --muted: #94a3b8;
  --muted-strong: #cbd5e1;
  --border: rgba(148, 163, 184, 0.22);
  --primary: #60a5fa;
  --primary-dark: #3b82f6;
  --primary-soft: rgba(37, 99, 235, 0.18);
  --accent: #22d3ee;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top left, rgba(37, 99, 235, 0.18), transparent 34rem),
    radial-gradient(circle at top right, rgba(8, 145, 178, 0.16), transparent 34rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(148, 163, 184, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.08) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(to bottom, black, transparent 74%);
}

button,
input,
select {
  font: inherit;
}

button,
summary,
a,
select,
input {
  -webkit-tap-highlight-color: transparent;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(18px);
  background: color-mix(in srgb, var(--bg-soft) 82%, transparent);
  border-bottom: 1px solid var(--border);
}

.header-inner,
.page-shell,
.site-footer {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.header-inner {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  text-decoration: none;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--primary-soft), rgba(34, 211, 238, 0.18));
  border: 1px solid var(--border);
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.14);
}

.brand strong {
  display: block;
  font-size: 1rem;
  letter-spacing: -0.02em;
}

.brand small {
  display: block;
  color: var(--muted);
  font-size: 0.78rem;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  user-select: none;
}

.switch {
  position: relative;
  display: inline-block;
  width: 54px;
  height: 30px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background: #cbd5e1;
  border-radius: 999px;
  transition: 180ms ease;
  border: 1px solid var(--border);
}

.slider::before {
  content: "";
  position: absolute;
  height: 22px;
  width: 22px;
  left: 4px;
  top: 3px;
  background: white;
  border-radius: 50%;
  transition: 180ms ease;
  box-shadow: 0 3px 10px rgba(15, 23, 42, 0.24);
}

.switch input:checked + .slider {
  background: var(--primary);
}

.switch input:checked + .slider::before {
  transform: translateX(24px);
}

.page-shell {
  padding: 28px 0 48px;
  position: relative;
  z-index: 1;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
}

.hero-card {
  padding: clamp(24px, 5vw, 48px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  overflow: hidden;
  position: relative;
}

.hero-card::after {
  content: "";
  position: absolute;
  width: 260px;
  height: 260px;
  right: -90px;
  top: -80px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.18), transparent 70%);
  pointer-events: none;
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--primary);
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-size: 0.72rem;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 16px;
  font-size: clamp(2rem, 4vw, 3.15rem);
  line-height: 1.04;
  letter-spacing: -0.07em;
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.25rem, 2vw, 1.7rem);
  letter-spacing: -0.04em;
}

h3 {
  margin-bottom: 12px;
  letter-spacing: -0.03em;
}

.hero-copy p:not(.eyebrow) {
  color: var(--muted-strong);
  font-size: 1.03rem;
  margin-bottom: 0;
}

.hero-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 180px;
  z-index: 1;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  padding: 12px 18px;
  font-weight: 800;
  cursor: pointer;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button-primary {
  color: white;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.22);
}

.button-secondary {
  color: var(--text);
  background: var(--primary-soft);
  border: 1px solid var(--border);
}

.summary-grid {
  position: sticky;
  top: 88px;
  z-index: 15;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin: 6px 0 18px;
  padding: 12px 0;
  backdrop-filter: blur(18px);
}

.metric-card,
.breakdown-item {
  background: var(--card-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: 0 16px 40px rgba(15, 23, 42, 0.06);
}

.metric-card span,
.breakdown-item span {
  display: block;
  color: var(--muted);
  font-weight: 700;
  font-size: 0.83rem;
}

.metric-card strong,
.breakdown-item strong {
  display: block;
  margin: 8px 0 4px;
  font-size: clamp(1.45rem, 3vw, 2.1rem);
  letter-spacing: -0.05em;
}

.metric-card small,
.breakdown-item small,
.progress-block small,
.muted-note,
.disclaimer {
  color: var(--muted);
}

.accent-card {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
}

.accent-card span,
.accent-card small {
  color: rgba(255, 255, 255, 0.82);
}

.layout-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  gap: 18px;
  align-items: start;
}

.form-card,
.insights-card,
.breakdown-card,
.scenario-card,
.sources-card {
  padding: clamp(20px, 3vw, 30px);
}

.form-card {
  position: relative;
  z-index: 2;
}

.section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
}

.scenario-actions {
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  flex-wrap: wrap;
}

.compact-heading {
  margin-bottom: 18px;
}

.live-badge,
.muted-note {
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--primary-soft);
  border: 1px solid var(--border);
  font-size: 0.78rem;
  font-weight: 800;
}

.input-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

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

.compact-heading + .input-grid,
.compact-heading + .expense-grid {
  margin-top: 0;
}

.field-group {
  min-width: 0;
}

.field-group label {
  min-height: 28px;
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--muted-strong);
  font-size: 0.9rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.field-group input,
.field-group select {
  width: 100%;
  height: 48px;
  color: var(--text);
  background: color-mix(in srgb, var(--card-solid) 88%, transparent);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0 14px;
  outline: none;
  transition: border 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.field-group input:focus,
.field-group select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 18%, transparent);
}

.field-group input:disabled {
  opacity: 1;
  color: var(--primary);
  font-weight: 800;
  background: var(--primary-soft);
}

.input-prefix,
.input-suffix {
  display: flex;
  align-items: center;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--card-solid) 88%, transparent);
}

.input-prefix:focus-within,
.input-suffix:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 18%, transparent);
}

.input-prefix span,
.input-suffix span {
  color: var(--muted);
  font-weight: 900;
  padding: 0 12px;
}

.input-prefix input,
.input-suffix input {
  border: 0;
  border-radius: 0;
  box-shadow: none !important;
  background: transparent;
}

.checkbox-row {
  min-height: 76px;
  display: grid;
  grid-template-columns: 22px 1fr;
  align-items: center;
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--card-solid) 75%, transparent);
}

.checkbox-row input {
  width: 20px;
  height: 20px;
  accent-color: var(--primary);
}

.checkbox-row label {
  margin: 0;
}

.info-popover {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.info-popover summary {
  list-style: none;
  width: 20px;
  height: 20px;
  display: inline-grid;
  place-items: center;
  border-radius: 999px;
  color: var(--primary);
  background: var(--primary-soft);
  border: 1px solid var(--border);
  font-size: 0.75rem;
  font-weight: 900;
  cursor: pointer;
}

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

.popover-panel {
  position: absolute;
  z-index: 30;
  top: 28px;
  left: -10px;
  width: min(300px, calc(100vw - 36px));
  padding: 14px;
  background: var(--card-solid);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: var(--shadow);
  color: var(--text);
  font-size: 0.82rem;
  font-weight: 500;
}

.popover-panel.wide {
  width: min(390px, calc(100vw - 36px));
}

.input-grid > .field-group:nth-child(even) .popover-panel {
  left: auto;
  right: -10px;
}

.popover-panel p {
  margin-bottom: 10px;
  color: var(--muted-strong);
}

.popover-panel a,
.source-list a {
  color: var(--primary);
  font-weight: 800;
  text-decoration: none;
}

.popover-panel a:hover,
.source-list a:hover {
  text-decoration: underline;
}

.insights-card {
  position: sticky;
  top: 96px;
}

.progress-block {
  padding: 18px;
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--card-solid) 78%, transparent);
  border: 1px solid var(--border);
  margin-bottom: 14px;
}

.progress-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
  font-weight: 800;
}

.progress-track {
  width: 100%;
  height: 10px;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in srgb, var(--muted) 18%, transparent);
  margin-bottom: 10px;
}

.progress-track span {
  display: block;
  width: 0%;
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width 180ms ease;
}

.callout {
  padding: 18px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--primary-soft), rgba(34, 211, 238, 0.12));
  border: 1px solid var(--border);
}

.callout p {
  margin: 6px 0 0;
  color: var(--muted-strong);
}

.breakdown-card,
.scenario-card,
.sources-card {
  margin-top: 18px;
}

.breakdown-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.formula-panel {
  margin-top: 18px;
  padding: 20px;
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--card-solid) 78%, transparent);
  border: 1px solid var(--border);
}

.formula-panel summary {
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--text);
  font-size: 1.08rem;
  font-weight: 800;
  cursor: pointer;
}

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

.formula-panel summary::after {
  content: "+";
  width: 28px;
  height: 28px;
  display: inline-grid;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 999px;
  color: var(--primary);
  background: var(--primary-soft);
  border: 1px solid var(--border);
  font-weight: 900;
}

.formula-panel[open] summary {
  margin-bottom: 12px;
}

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

.formula-panel ol {
  margin: 0;
  padding-left: 20px;
  color: var(--muted-strong);
}

.formula-panel li + li {
  margin-top: 8px;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 1120px;
  background: var(--card-solid);
}

th,
td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

th {
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: color-mix(in srgb, var(--primary-soft) 55%, transparent);
}

td {
  font-weight: 700;
}

.base-scenario td {
  background: color-mix(in srgb, var(--primary-soft) 42%, transparent);
  color: var(--text);
}

tr:last-child td {
  border-bottom: 0;
}

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

.source-list a {
  padding: 14px;
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--card-solid) 75%, transparent);
  border: 1px solid var(--border);
}

.disclaimer {
  margin: 18px 0 0;
}

.site-footer {
  padding: 26px 0 34px;
  color: var(--muted);
  text-align: center;
  position: relative;
  z-index: 1;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 22px;
  transform: translate(-50%, 20px);
  opacity: 0;
  pointer-events: none;
  padding: 12px 16px;
  border-radius: 999px;
  background: var(--text);
  color: var(--bg-soft);
  font-weight: 800;
  box-shadow: var(--shadow);
  transition: 180ms ease;
  z-index: 40;
}

.toast.show {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (max-width: 980px) {
  .summary-grid,
  .breakdown-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .insights-card {
    position: static;
  }

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

@media (max-width: 720px) {
  .header-inner,
  .page-shell,
  .site-footer {
    width: min(100% - 22px, 1180px);
  }

  .header-inner {
    min-height: 68px;
  }

  .brand small {
    display: none;
  }

  .hero-card,
  .section-heading {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions {
    flex-direction: row;
    min-width: 0;
  }

  .hero-actions .button {
    flex: 1;
  }

  .summary-grid,
  .input-grid,
  .expense-grid,
  .breakdown-grid,
  .source-list {
    grid-template-columns: 1fr;
  }

  .summary-grid {
    position: static;
    padding: 0;
  }

  .form-card,
  .insights-card,
  .breakdown-card,
  .scenario-card,
  .sources-card {
    padding: 18px;
    border-radius: 22px;
  }

  .metric-card,
  .breakdown-item {
    padding: 16px;
  }

  .popover-panel,
  .popover-panel.wide {
    position: fixed;
    left: 12px;
    right: 12px;
    top: auto;
    bottom: 18px;
    width: auto;
    max-height: 70vh;
    overflow-y: auto;
  }

  .input-grid > .field-group:nth-child(even) .popover-panel {
    left: 12px;
    right: 12px;
  }
}

@media (max-width: 440px) {
  h1 {
    font-size: 2.2rem;
  }

  .theme-toggle span {
    display: none;
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
  }
}