:root {
  color-scheme: light;
  --bg: #eef4f7;
  --surface: #fbfdff;
  --surface-strong: #ffffff;
  --text: #17202a;
  --muted: #5f6f7b;
  --line: #d8e2e8;
  --primary: #16756f;
  --primary-strong: #0d5651;
  --accent: #b45d18;
  --shadow: 0 18px 60px rgb(23 32 42 / 10%);
  --radius: 8px;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101820;
  --surface: #17222b;
  --surface-strong: #20313c;
  --text: #eef5f7;
  --muted: #a8b7c1;
  --line: #314653;
  --primary: #59c1b7;
  --primary-strong: #93ddd6;
  --accent: #f0a45f;
  --shadow: 0 18px 60px rgb(0 0 0 / 28%);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #101820;
    --surface: #17222b;
    --surface-strong: #20313c;
    --text: #eef5f7;
    --muted: #a8b7c1;
    --line: #314653;
    --primary: #59c1b7;
    --primary-strong: #93ddd6;
    --accent: #f0a45f;
    --shadow: 0 18px 60px rgb(0 0 0 / 28%);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgb(23 108 103 / 16%), transparent 30rem),
    linear-gradient(135deg, var(--bg), color-mix(in srgb, var(--surface), var(--accent) 7%));
}

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

button,
input,
select {
  color: inherit;
}

a {
  color: inherit;
}

.skip-link {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 10;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius);
  background: var(--text);
  color: var(--surface);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

.app-shell {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1rem 0 3rem;
}

.topbar,
.section-heading,
.hero,
.section-grid,
.settings-grid,
.input-row,
.expense-row,
.participant-row,
.hero-actions {
  display: flex;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 76px;
  padding: 0.8rem 0;
  background: color-mix(in srgb, var(--bg), transparent 8%);
  backdrop-filter: blur(18px);
}

.topbar h1,
.hero h2,
.panel h2 {
  margin: 0;
  line-height: 1.05;
  letter-spacing: 0;
}

.topbar h1 {
  font-size: clamp(1.35rem, 4vw, 1.8rem);
}

.eyebrow {
  margin: 0 0 0.35rem;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav {
  display: flex;
  gap: 0.35rem;
  padding: 0.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface), transparent 20%);
}

.nav a {
  min-width: 5.75rem;
  padding: 0.55rem 0.75rem;
  border-radius: calc(var(--radius) - 2px);
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
  text-align: center;
  text-decoration: none;
}

.nav a:hover,
.nav a:focus-visible,
.nav a[aria-current="page"] {
  background: var(--surface-strong);
  color: var(--text);
  outline: none;
}

main {
  display: grid;
  gap: 1rem;
}

.hero {
  align-items: stretch;
  justify-content: space-between;
  gap: 1rem;
  min-height: 360px;
  padding: clamp(1.25rem, 4vw, 3rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgb(22 117 111 / 14%), transparent 55%),
    linear-gradient(160deg, transparent 60%, rgb(180 93 24 / 12%)),
    var(--surface);
  box-shadow: var(--shadow);
}

.hero-copy {
  align-self: center;
  max-width: 690px;
}

.hero h2 {
  max-width: 12ch;
  font-size: clamp(2.3rem, 8vw, 5.6rem);
}

.hero p:not(.eyebrow) {
  max-width: 58ch;
  margin: 1.25rem 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.15rem);
  line-height: 1.6;
}

.hero-actions {
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.5rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.75rem;
  padding: 0.7rem 1rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
}

.button.primary {
  background: var(--primary);
  color: white;
}

.button.primary:hover,
.button.primary:focus-visible {
  background: var(--primary-strong);
}

.button.secondary {
  border-color: var(--line);
  background: var(--surface-strong);
}

.button.secondary:hover,
.button.secondary:focus-visible {
  border-color: var(--primary);
}

.status-panel {
  display: grid;
  align-self: flex-end;
  min-width: 220px;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
}

.status-panel div {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.status-panel strong {
  margin-top: 1.4rem;
  font-size: 4rem;
  line-height: 0.9;
}

.status-panel span:last-child {
  color: var(--muted);
}

.status-dot {
  width: 0.65rem;
  height: 0.65rem;
  border-radius: 999px;
  background: #2fa36b;
}

.section-grid {
  align-items: flex-start;
  gap: 1rem;
}

.workspace-panel {
  flex: 1 1 680px;
}

.panel {
  padding: clamp(1rem, 3vw, 1.5rem);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.section-heading {
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.panel h2 {
  font-size: clamp(1.35rem, 3vw, 2rem);
}

.expense-form {
  display: grid;
  gap: 1rem;
}

.expense-form label,
.field span {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

.form-grid {
  display: grid;
  grid-template-columns: minmax(12rem, 1fr) minmax(8rem, 0.45fr) minmax(10rem, 0.55fr);
  gap: 0.75rem;
}

.input-row {
  gap: 0.6rem;
}

input,
select {
  width: 100%;
  min-height: 2.75rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  padding: 0.65rem 0.75rem;
}

input:focus,
select:focus,
button:focus-visible,
a:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--primary), transparent 62%);
  outline-offset: 2px;
}

.split-fieldset {
  display: grid;
  gap: 0.75rem;
  margin: 0;
  padding: 0.85rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.split-fieldset legend {
  padding: 0 0.35rem;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

.choice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(8rem, 1fr));
  gap: 0.5rem;
}

.choice {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  min-height: 2.45rem;
  padding: 0.55rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
}

.choice input {
  width: 1rem;
  min-height: 1rem;
  accent-color: var(--primary);
}

.choice span {
  color: var(--text);
  overflow-wrap: anywhere;
}

.split-all {
  width: fit-content;
}

.expense-list,
.participant-list {
  display: grid;
  gap: 0.6rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.empty-state {
  margin: 0;
  padding: 1rem;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  color: var(--muted);
}

.expense-row,
.participant-row {
  align-items: center;
  gap: 0.75rem;
  min-height: 3.25rem;
  padding: 0.7rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
}

.expense-row > input {
  width: 1.15rem;
  min-height: 1.15rem;
  accent-color: var(--primary);
}

.expense-details,
.participant-row span {
  flex: 1;
  overflow-wrap: anywhere;
}

.expense-details {
  display: grid;
  gap: 0.25rem;
}

.expense-details span {
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.35;
}

.expense-row[data-settled="true"] .expense-details {
  color: var(--muted);
  text-decoration: line-through;
}

.icon-button {
  width: 2.25rem;
  height: 2.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: transparent;
  cursor: pointer;
}

.icon-button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.participant-form {
  margin-top: 1rem;
}

.participant-list {
  margin-top: 0.75rem;
}

.stat-list {
  display: grid;
  gap: 0.75rem;
  min-width: 240px;
  margin: 1rem 0 0;
}

.stat-list div {
  display: grid;
  gap: 0.2rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--line);
}

.stat-list dt {
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 800;
}

.stat-list dd {
  margin: 0;
  font-weight: 800;
}

code {
  padding: 0.1rem 0.25rem;
  border-radius: 4px;
  background: color-mix(in srgb, var(--primary), transparent 88%);
}

.settings-panel {
  margin-bottom: 1rem;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.5rem 0 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.site-footer a {
  color: var(--primary);
}

.settings-grid {
  gap: 1rem;
}

.field {
  display: grid;
  flex: 1;
  gap: 0.45rem;
}

.save-state {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

@media (max-width: 780px) {
  .topbar,
  .hero,
  .section-grid,
  .settings-grid,
  .input-row {
    flex-direction: column;
  }

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

  .topbar {
    align-items: stretch;
    position: static;
  }

  .nav {
    overflow-x: auto;
  }

  .nav a {
    flex: 1;
  }

  .hero h2 {
    max-width: 9ch;
  }

  .status-panel {
    width: 100%;
  }

  .section-heading {
    align-items: flex-start;
    flex-direction: column;
  }
}