:root {
  color-scheme: light;
  --bg: #eef2f8;
  --bg-deep: #e5ebf5;
  --panel: rgba(255, 255, 255, 0.76);
  --panel-strong: rgba(255, 255, 255, 0.96);
  --panel-line: rgba(255, 255, 255, 0.72);
  --grid: #d8e0ec;
  --grid-strong: #c7d0df;
  --header-bg: rgba(245, 247, 251, 0.96);
  --header-bg-strong: rgba(237, 242, 249, 0.98);
  --text: #162033;
  --muted: #5f6c84;
  --accent: #0b66ff;
  --accent-soft: rgba(11, 102, 255, 0.12);
  --accent-strong: rgba(11, 102, 255, 0.22);
  --accent-text: #0b56cf;
  --shadow: 0 26px 70px rgba(15, 23, 42, 0.12);
  --shadow-soft: 0 12px 30px rgba(15, 23, 42, 0.08);
  --header-height: 42px;
  --index-width: 60px;
  --cell-width: 128px;
  --cell-height: 34px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(circle at top left, rgba(11, 102, 255, 0.12), transparent 22%),
    radial-gradient(circle at top right, rgba(255, 255, 255, 0.72), transparent 28%),
    linear-gradient(180deg, #f8fbff 0%, var(--bg) 45%, var(--bg-deep) 100%);
  color: var(--text);
}

body {
  min-height: 100vh;
  letter-spacing: -0.01em;
}

.app-shell {
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 18px;
  min-height: 100vh;
  padding: 18px;
}

.topbar,
.grid-frame {
  background: var(--panel);
  backdrop-filter: blur(22px) saturate(1.15);
  border: 1px solid var(--panel-line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}

.topbar {
  display: grid;
  gap: 16px;
  padding: 18px 20px;
}

.brand-lockup {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-mark {
  width: 18px;
  height: 44px;
  border-radius: 999px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.72) 0%, rgba(255, 255, 255, 0) 28%),
    linear-gradient(180deg, #60a5fa 0%, #1d4ed8 100%);
  box-shadow:
    inset 0 1px 2px rgba(255, 255, 255, 0.45),
    0 8px 18px rgba(29, 78, 216, 0.22);
}

.eyebrow,
.brand-lockup h1 {
  margin: 0;
}

.eyebrow {
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.brand-lockup h1 {
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.formula-bar {
  display: grid;
  grid-template-columns: auto auto 1fr;
  align-items: center;
  gap: 10px;
  padding: 8px;
  border-radius: 20px;
  background: rgba(244, 247, 252, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.68);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.72);
}

.formula-label,
.name-box,
.formula-input {
  min-height: 46px;
  border: 1px solid var(--grid);
  border-radius: 14px;
  background: var(--panel-strong);
  box-shadow: var(--shadow-soft);
}

.formula-label,
.name-box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  color: var(--muted);
  font-weight: 700;
}

.formula-label {
  min-width: 52px;
  background: linear-gradient(180deg, #fbfcfe 0%, #eef3fa 100%);
}

.name-box {
  min-width: 84px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.formula-input {
  width: 100%;
  padding: 0 16px;
  font: inherit;
  color: var(--text);
  outline: none;
  border-color: rgba(199, 208, 223, 0.9);
  transition: border-color 120ms ease, box-shadow 120ms ease, background-color 120ms ease;
}

.formula-input:hover {
  background: #ffffff;
}

.formula-input:focus {
  border-color: rgba(11, 102, 255, 0.45);
  box-shadow:
    var(--shadow-soft),
    0 0 0 4px rgba(11, 102, 255, 0.12);
}

.formula-input::placeholder {
  color: #98a2b3;
}

.grid-frame {
  min-height: 0;
  overflow: hidden;
  padding: 10px;
}

.grid-scroll {
  height: calc(100vh - 186px);
  min-height: 460px;
  overflow: auto;
  border-radius: 18px;
  border: 1px solid rgba(215, 223, 236, 0.92);
  background:
    linear-gradient(180deg, rgba(247, 249, 252, 0.9) 0%, rgba(241, 245, 251, 0.62) 100%),
    #f5f7fb;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.85);
}

.sheet-grid {
  border-collapse: separate;
  border-spacing: 0;
  table-layout: fixed;
  width: max-content;
  min-width: 100%;
  font-size: 13px;
}

.sheet-grid th,
.sheet-grid td {
  border-right: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
  height: var(--cell-height);
  padding: 0 10px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  position: relative;
}

.sheet-grid th {
  background: var(--header-bg);
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  text-align: center;
  user-select: none;
  backdrop-filter: blur(18px);
}

.corner-cell,
.row-header {
  position: sticky;
  left: 0;
  z-index: 3;
}

.corner-cell {
  top: 0;
  z-index: 5;
  width: var(--index-width);
  min-width: var(--index-width);
  border-top: 0;
  background:
    linear-gradient(135deg, rgba(11, 102, 255, 0.14) 0%, rgba(11, 102, 255, 0) 46%),
    var(--header-bg-strong);
}

.column-header {
  position: sticky;
  top: 0;
  z-index: 4;
  min-width: var(--cell-width);
  width: var(--cell-width);
  height: var(--header-height);
  border-top: 0;
  box-shadow: inset 0 -1px 0 rgba(199, 208, 223, 0.95);
}

.row-header {
  min-width: var(--index-width);
  width: var(--index-width);
  background: var(--header-bg);
  text-align: right;
  padding-right: 12px;
  font-variant-numeric: tabular-nums;
}

.header-label-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  width: 100%;
  position: relative;
}

.header-label-text {
  min-width: 0;
  flex: 1;
}

.header-action-trigger,
.header-action-button {
  border: 0;
  font: inherit;
}

.header-action-trigger {
  width: 22px;
  height: 22px;
  padding: 0;
  border-radius: 999px;
  background: transparent;
  color: #98a2b3;
  cursor: pointer;
}

.header-action-trigger:hover,
.header-action-trigger[aria-expanded="true"] {
  background: rgba(26, 115, 232, 0.08);
  color: #175cd3;
}

.header-action-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  display: grid;
  gap: 4px;
  min-width: 138px;
  padding: 8px;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 18px 36px rgba(15, 23, 42, 0.14);
  z-index: 20;
}

.header-action-button {
  padding: 8px 10px;
  border-radius: 10px;
  background: transparent;
  color: var(--text);
  text-align: left;
  cursor: pointer;
}

.header-action-button:hover {
  background: rgba(26, 115, 232, 0.08);
}

.sheet-grid tr > *:first-child {
  border-left: 0;
}

.sheet-grid tr:first-child > * {
  border-top: 0;
}

.sheet-grid td {
  min-width: var(--cell-width);
  width: var(--cell-width);
  background: rgba(255, 255, 255, 0.9);
  color: var(--text);
  cursor: cell;
  user-select: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.32);
}

.sheet-grid td:hover {
  background: #fcfdff;
}

.cell-range {
  background: linear-gradient(180deg, rgba(11, 102, 255, 0.06) 0%, var(--accent-soft) 100%) !important;
  box-shadow: inset 0 0 0 1px rgba(11, 102, 255, 0.08);
}

.cell-active {
  background: rgba(255, 255, 255, 0.98) !important;
  box-shadow:
    inset 0 0 0 2px var(--accent),
    0 0 0 1px rgba(255, 255, 255, 0.95),
    0 10px 18px rgba(11, 102, 255, 0.1);
  z-index: 2;
}

.cell-active::after {
  content: "";
  position: absolute;
  right: -4px;
  bottom: -4px;
  width: 8px;
  height: 8px;
  border-radius: 3px;
  background: var(--accent);
  border: 2px solid #ffffff;
  box-shadow: 0 2px 6px rgba(11, 102, 255, 0.22);
}

.header-active,
.header-range {
  color: var(--accent-text) !important;
}

.header-active {
  background: linear-gradient(180deg, #f3f7ff 0%, #e8f0ff 100%) !important;
  box-shadow:
    inset 0 -2px 0 var(--accent),
    inset 0 1px 0 rgba(255, 255, 255, 0.78);
}

.header-range {
  background: linear-gradient(180deg, rgba(236, 243, 255, 0.98) 0%, rgba(230, 239, 255, 0.98) 100%) !important;
}

.sheet-grid:focus-within .cell-active {
  box-shadow:
    inset 0 0 0 2px var(--accent),
    0 0 0 1px rgba(255, 255, 255, 0.95),
    0 12px 22px rgba(11, 102, 255, 0.14);
}

@media (max-width: 900px) {
  .app-shell {
    padding: 12px;
    gap: 12px;
  }

  .topbar {
    padding: 14px;
  }

  .brand-lockup h1 {
    font-size: 22px;
  }

  .formula-bar {
    grid-template-columns: auto 1fr;
  }

  .formula-input {
    grid-column: 1 / -1;
  }

  .grid-scroll {
    height: calc(100vh - 208px);
  }

  .header-action-menu {
    left: 0;
    right: auto;
  }
}