:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --bg: #f3f4f6;
  --surface: #ffffff;
  --surface-soft: #f8fafc;
  --text: #111827;
  --muted: #64748b;
  --muted-strong: #475569;
  --line: #e2e8f0;
  --accent: #111111;
  --accent-soft: #e5e5e5;
  --positive: #15803d;
  --negative: #dc2626;
  --today-bg: #f1f1f1;
  --today-border: #bdbdbd;
  --shadow: 0 14px 36px rgba(15, 23, 42, 0.08);
  --radius: 20px;
}

* { box-sizing: border-box; }
html { min-height: 100%; }
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
}
button, input { font: inherit; }
button { cursor: pointer; }
button:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.25);
  outline-offset: 2px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #000000;
  --surface: #111111;
  --surface-soft: #1b1b1b;
  --text: #ffffff;
  --muted: #94a3b8;
  --muted-strong: #dddddd;
  --line: #333333;
  --accent: #ffffff;
  --accent-soft: #2a2a2a;
  --positive: #ffffff;
  --negative: #dddddd;
  --today-bg: #1a1a1a;
  --today-border: #555555;
  --shadow: 0 18px 42px rgba(0, 0, 0, 0.3);
}

.app-shell {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 48px;
}

.topbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 34px;
}
.topbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.theme-toggle {
  position: relative;
  display: inline-grid;
  place-items: center;
  overflow: hidden;
  border-radius: 12px;
}
.theme-icon {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.theme-icon-sun { display: none; }
[data-theme="dark"] .theme-icon-moon { display: none; }
[data-theme="dark"] .theme-icon-sun { display: block; }
[data-theme="dark"] .button:hover,
[data-theme="dark"] .icon-button:hover {
  border-color: #475569;
}
.eyebrow,
.section-kicker {
  margin: 0 0 5px;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.14em;
}
h1, h2, p { margin-top: 0; }
h1 {
  margin-bottom: 8px;
  font-size: clamp(1.8rem, 4vw, 2.65rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
}
h2 {
  margin-bottom: 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
  letter-spacing: -0.025em;
}
.subtitle {
  margin-bottom: 0;
  color: var(--muted);
}

.button,
.icon-button,
.back-button {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--text);
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}
.button:hover,
.icon-button:hover,
.back-button:hover {
  transform: translateY(-1px);
  border-color: #cbd5e1;
}
.button {
  padding: 11px 16px;
  border-radius: 12px;
  font-weight: 700;
}
.button-secondary { box-shadow: 0 5px 18px rgba(15, 23, 42, 0.05); }
.icon-button {
  width: 42px;
  height: 42px;
  padding: 0;
  border-radius: 12px;
  font-size: 1.5rem;
  line-height: 1;
}
.back-button {
  margin-bottom: 10px;
  padding: 7px 0;
  border: 0;
  background: transparent;
  color: var(--muted);
  font-weight: 700;
}

.section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}
.year-controls {
  display: flex;
  gap: 8px;
}
.month-heading { align-items: center; }

.year-summary {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}
.summary-card {
  padding: 15px 16px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 5px 20px rgba(15, 23, 42, 0.04);
}
.summary-card span {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.8rem;
}
.summary-card strong { font-size: 1.05rem; }

.months-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.month-card {
  display: block;
  width: 100%;
  padding: 18px;
  text-align: left;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.03);
  transition: transform 140ms ease, border-color 140ms ease, box-shadow 140ms ease;
}
.month-card:hover {
  transform: translateY(-2px);
  border-color: #cbd5e1;
  box-shadow: var(--shadow);
}
.month-card.is-current {
  border-color: var(--today-border);
  box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.08);
}
.month-card-header {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  margin-bottom: 18px;
}
.month-name {
  font-weight: 800;
  text-transform: capitalize;
}
.month-status {
  color: var(--muted);
  font-size: 0.75rem;
}
.month-net-label {
  margin-bottom: 4px;
  color: var(--muted);
  font-size: 0.76rem;
}
.month-net {
  font-size: 1.35rem;
  font-weight: 850;
  letter-spacing: -0.02em;
}
.month-net.positive,
.value-positive { color: var(--positive); }
.month-net.negative,
.value-negative { color: var(--negative); }

.month-help {
  margin-bottom: 14px;
  padding: 13px 15px;
  color: #475569;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 14px;
  font-size: 0.88rem;
}

.sheet-card {
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.table-scroll { overflow-x: auto; }
.sheet-table {
  width: 100%;
  min-width: 680px;
  border-collapse: collapse;
}
.sheet-table th,
.sheet-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
}
.sheet-table thead th {
  position: sticky;
  top: 0;
  z-index: 1;
  background: var(--surface-soft);
  color: var(--muted-strong);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  text-align: left;
  text-transform: uppercase;
}
.sheet-table tbody tr:last-child td { border-bottom: 0; }
.sheet-table tbody tr.is-today { background: #eff6ff; }
.day-cell {
  width: 90px;
  font-weight: 800;
}
.today-badge {
  display: inline-block;
  margin-left: 7px;
  padding: 3px 7px;
  border-radius: 999px;
  color: var(--accent);
  background: var(--accent-soft);
  font-size: 0.68rem;
  font-weight: 800;
}
.money-input {
  width: 100%;
  max-width: 260px;
  padding: 10px 12px;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.money-input:focus {
  border-color: #93c5fd;
}
.net-cell {
  min-width: 145px;
  font-weight: 800;
}
.month-net-button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-width: 190px;
  padding: 13px 16px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.month-net-button span {
  display: block;
  color: var(--muted);
  font-size: 0.73rem;
}
.month-net-button strong {
  display: block;
  font-size: 1.05rem;
}

.modal-backdrop {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 18px;
  background: rgba(15, 23, 42, 0.48);
  backdrop-filter: blur(5px);
  z-index: 20;
}
.modal {
  width: min(650px, 100%);
  padding: 22px;
  background: var(--surface);
  border-radius: 22px;
  box-shadow: 0 30px 90px rgba(15, 23, 42, 0.25);
}
.modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
}
.modal-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}
.stat-card {
  padding: 16px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 16px;
}
.stat-card span {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 0.8rem;
}
.stat-card strong {
  display: block;
  font-size: 1.15rem;
}
.stat-highlight {
  border-color: #bfdbfe;
  background: var(--today-bg);
}
.modal-note {
  margin: 18px 2px 2px;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.5;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 30;
  max-width: min(360px, calc(100vw - 36px));
  padding: 12px 15px;
  color: white;
  background: #111827;
  border-radius: 12px;
  box-shadow: 0 16px 34px rgba(15, 23, 42, 0.24);
  transform: translateY(16px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease, transform 160ms ease;
}
.toast.show {
  opacity: 1;
  transform: translateY(0);
}
.hidden { display: none !important; }

@media (max-width: 900px) {
  .months-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 700px) {
  .app-shell {
    width: min(100% - 20px, 1180px);
    padding-top: 18px;
  }
  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }
  .topbar-actions {
    width: 100%;
  }
  .topbar-actions .button {
    flex: 1;
  }
  .topbar-actions .theme-toggle {
    flex: 0 0 44px;
  }
  .section-heading.month-heading {
    align-items: flex-start;
    flex-direction: column;
  }
  .topbar .button { width: 100%; }
  .year-summary { grid-template-columns: 1fr; }
  .months-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .month-net-button { width: 100%; }
}
@media (max-width: 430px) {
  .months-grid { grid-template-columns: 1fr; }
  .month-card { padding: 16px; }
  .modal-stats { grid-template-columns: 1fr; }
}
@media (pointer: coarse) {
  .button,
  .icon-button,
  .back-button,
  .month-card,
  .money-input,
  .month-net-button {
    min-height: 44px;
  }
  .money-input { font-size: 16px; }
  .theme-toggle { -webkit-tap-highlight-color: transparent; }
}