/* ==========================================================================
   NIFTY 50 Waterfall Chart — style.css
   Art direction: Financial data tool → precise, dark, data-dense
   Palette: Dark slate surfaces + green/red data accents
   Typography: Satoshi (body) + Instrument Serif (display title only)
   Density: Dense — this is a data dashboard, not an editorial page
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. DESIGN TOKENS
   -------------------------------------------------------------------------- */

:root {
  /* Fonts */
  --font-body:    'Satoshi', 'Inter', system-ui, sans-serif;
  --font-display: 'Instrument Serif', Georgia, serif;

  /* Type scale (fluid) */
  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);

  /* Spacing (4px base) */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Radius */
  --radius-sm:   0.375rem;
  --radius-md:   0.5rem;
  --radius-lg:   0.75rem;
  --radius-xl:   1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-wide: 1280px;
  --content-default: 960px;

  /* Chart colours (spec-exact values) */
  --chart-green:       #22c55e;
  --chart-red:         #ef4444;
  --chart-non-trading: #1e293b;
  --chart-bridge:      #94a3b8;
  --chart-grid:        #1e293b;
  --chart-axis-label:  #64748b;

  /* Weekday badge colours (from spec) */
  --badge-mon-bg:  #dbeafe; --badge-mon-text:  #1e40af;
  --badge-tue-bg:  #ede9fe; --badge-tue-text:  #5b21b6;
  --badge-wed-bg:  #dcfce7; --badge-wed-text:  #166534;
  --badge-thu-bg:  #fef9c3; --badge-thu-text:  #854d0e;
  --badge-fri-bg:  #ffedd5; --badge-fri-text:  #9a3412;
  --badge-sat-bg:  #f1f5f9; --badge-sat-text:  #475569;
  --badge-sun-bg:  #f1f5f9; --badge-sun-text:  #475569;
  --badge-hol-bg:  #fce7f3; --badge-hol-text:  #9d174d;
}

/* Dark theme (default — always dark for this product) */
[data-theme="dark"], :root {
  --color-bg:              #0f172a;
  --color-surface:         #1e293b;
  --color-surface-2:       #243044;
  --color-surface-offset:  #162032;
  --color-border:          #2d3f55;
  --color-divider:         #1e2d3d;
  --color-text:            #e2e8f0;
  --color-text-muted:      #94a3b8;
  --color-text-faint:      #475569;
  --color-primary:         #22c55e;
  --color-primary-hover:   #16a34a;
  --color-danger:          #ef4444;
  --color-warning:         #f59e0b;
  --shadow-sm: 0 1px 3px oklch(0 0 0 / 0.3);
  --shadow-md: 0 4px 12px oklch(0 0 0 / 0.4);
  --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.5);
}

/* --------------------------------------------------------------------------
   2. BASE RESET
   -------------------------------------------------------------------------- */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-16);
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

::selection {
  background: oklch(from var(--color-primary) l c h / 0.25);
  color: var(--color-text);
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* Accessibility helpers */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0;
  margin: -1px; overflow: hidden; clip: rect(0,0,0,0);
  white-space: nowrap; border-width: 0;
}
.sr-only-focusable:focus {
  position: static; width: auto; height: auto;
  overflow: visible; clip: auto; white-space: normal;
}

/* --------------------------------------------------------------------------
   3. SKELETON ANIMATION
   -------------------------------------------------------------------------- */

@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position:  200% 0; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-surface) 25%,
    var(--color-surface-2) 50%,
    var(--color-surface) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm);
  color: transparent !important;
  user-select: none;
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   4. SITE HEADER
   -------------------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  background: oklch(from var(--color-bg) l c h / 0.92);
}

.header-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-3) var(--space-6);
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: var(--space-6);
}

/* Brand */
.brand-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  transition: opacity var(--transition);
}
.brand-link:hover { opacity: 0.75; }

.brand-logo {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.brand-name {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* Chart title */
.header-title-group {
  min-width: 0;
}

.chart-title {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.title-accent {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  color: var(--color-text-muted);
}

.chart-subtitle {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-1);
}

/* Status badge */
.header-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-1);
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--color-text-faint);
  flex-shrink: 0;
}

.status-badge.live .status-dot {
  background: var(--chart-green);
  box-shadow: 0 0 6px oklch(from var(--chart-green) l c h / 0.6);
  animation: pulse-dot 2s ease-in-out infinite;
}

.status-badge.stale .status-dot { background: var(--color-warning); }
.status-badge.error .status-dot { background: var(--color-danger); }

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.last-updated {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------------------
   5. SUMMARY STATS — Row 1 (Component A)
   -------------------------------------------------------------------------- */

.summary-stats {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.stats-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding: var(--space-4) var(--space-6);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

.stat-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 500;
}

.stat-value {
  font-size: var(--text-xl);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  line-height: 1;
  min-width: 120px;
  min-height: 1.2em;
}

.stat-change {
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}

.stat-change.gain { color: var(--chart-green); }
.stat-change.loss { color: var(--chart-red); }
.stat-change.neutral { color: var(--color-text-muted); }

/* --------------------------------------------------------------------------
   6. CHART SECTION — Rows 2–3
   -------------------------------------------------------------------------- */

.chart-section {
  padding: var(--space-6) 0;
}

.chart-outer {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
  position: relative;
  min-height: 280px;
}

/* Error state */
.chart-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-16) var(--space-8);
  gap: var(--space-3);
  color: var(--color-text-muted);
}

.error-icon {
  width: 40px;
  height: 40px;
  color: var(--color-text-faint);
}

.error-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
}

.error-body {
  font-size: var(--text-sm);
  max-width: 36ch;
}

.btn-retry {
  margin-top: var(--space-2);
  padding: var(--space-2) var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  transition: background var(--transition), border-color var(--transition);
}
.btn-retry:hover {
  background: var(--color-surface);
  border-color: var(--color-text-muted);
}

/* Skeleton bars */
.chart-skeleton {
  width: 100%;
  height: 280px;
  display: flex;
  align-items: flex-end;
  gap: 3px;
  padding: var(--space-4) 0;
}

.skeleton-bars {
  display: flex;
  align-items: flex-end;
  gap: 3px;
  width: 100%;
  height: 100%;
}

.skeleton-bar {
  flex: 1;
  background: linear-gradient(
    90deg,
    var(--color-surface) 25%,
    var(--color-surface-2) 50%,
    var(--color-surface) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  min-height: 8px;
}

.skeleton-bar.non-trading {
  height: 100% !important;
  background: var(--chart-non-trading);
  animation: none;
  opacity: 0.5;
}

/* Chart scroll wrapper — horizontal scroll on mobile */
.chart-scroll-wrapper {
  width: 100%;
  overflow-x: auto;
  overflow-y: visible;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}

.chart-scroll-wrapper::-webkit-scrollbar {
  height: 4px;
}
.chart-scroll-wrapper::-webkit-scrollbar-track {
  background: transparent;
}
.chart-scroll-wrapper::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: var(--radius-full);
}

.chart-svg {
  display: block;
  min-width: 560px; /* prevents unreadable compression below 18px/col */
  width: 100%;
  height: 320px;
  overflow: visible;
}

/* --------------------------------------------------------------------------
   7. WEEKDAY WIN-RATE MATRIX — Row 4 (Component B)
   -------------------------------------------------------------------------- */

.analytics-section {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) 0;
}

.analytics-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.analytics-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
  gap: var(--space-4);
  flex-wrap: wrap;
}

.analytics-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
}

/* Period toggle buttons */
.period-toggle {
  display: flex;
  gap: var(--space-1);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 3px;
}

.period-btn {
  padding: var(--space-1) var(--space-3);
  border-radius: calc(var(--radius-lg) - 3px);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  transition: background var(--transition), color var(--transition);
}

.period-btn:hover:not(:disabled) {
  background: var(--color-surface-2);
  color: var(--color-text);
}

.period-btn.active {
  background: var(--color-surface-2);
  color: var(--color-text);
}

.period-btn.disabled,
.period-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* Weekday matrix grid */
.weekday-matrix {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.matrix-header,
.matrix-row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-2);
}

.matrix-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-variant-numeric: tabular-nums;
}

.header-cell {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-faint);
  background: transparent;
  padding-block: var(--space-1);
}

/* Weekday-specific badge colours on header cells */
.header-cell[data-day="mon"] { color: var(--badge-mon-text); }
.header-cell[data-day="tue"] { color: var(--badge-tue-text); }
.header-cell[data-day="wed"] { color: var(--badge-wed-text); }
.header-cell[data-day="thu"] { color: var(--badge-thu-text); }
.header-cell[data-day="fri"] { color: var(--badge-fri-text); }

.data-cell {
  font-size: var(--text-base);
  font-weight: 700;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  min-height: 52px;
  transition: background var(--transition);
}

/* Win-rate colour fill: app.js adds these classes */
.data-cell.high   { background: oklch(from var(--chart-green) l c h / 0.12); color: var(--chart-green); border-color: oklch(from var(--chart-green) l c h / 0.25); }
.data-cell.mid    { background: var(--color-surface); color: var(--color-text); }
.data-cell.low    { background: oklch(from var(--chart-red)   l c h / 0.12); color: var(--chart-red);   border-color: oklch(from var(--chart-red)   l c h / 0.25); }

.subtext-cell {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  font-variant-numeric: tabular-nums;
  background: transparent;
  border: none;
  padding-block: var(--space-1);
}

/* --------------------------------------------------------------------------
   8. ANALYTICS CARDS — Row 5
   -------------------------------------------------------------------------- */

.cards-section {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) 0 var(--space-10);
}

.cards-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

.analytics-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.card-title {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-faint);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--color-divider);
}

.card-body {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.card-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
}

.card-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.card-value {
  font-size: var(--text-sm);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  text-align: right;
  min-width: 60px;
  min-height: 1em;
}

/* Coloured values — applied by app.js */
.card-value.gain    { color: var(--chart-green); }
.card-value.loss    { color: var(--chart-red); }
.card-value.neutral { color: var(--color-text); }
.card-value.warning { color: var(--color-warning); }

/* --------------------------------------------------------------------------
   9. TOOLTIP
   -------------------------------------------------------------------------- */

.chart-tooltip {
  position: fixed;
  z-index: 9999;
  pointer-events: none;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-4);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  max-width: 220px;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 120ms ease, transform 120ms ease;
}

.chart-tooltip:not([hidden]) {
  opacity: 1;
  transform: translateY(0);
}

/* hidden attr: override display so transition still works */
.chart-tooltip[hidden] {
  display: flex !important;
  opacity: 0;
  pointer-events: none;
}

.tooltip-date {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tooltip-close {
  font-size: var(--text-base);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.tooltip-change {
  font-size: var(--text-sm);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.tooltip-change.gain { color: var(--chart-green); }
.tooltip-change.loss { color: var(--chart-red); }
.tooltip-change.neutral { color: var(--color-text-muted); }

/* --------------------------------------------------------------------------
   10. FOOTER
   -------------------------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-6) 0;
  background: var(--color-surface);
}

.footer-inner {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.footer-disclaimer {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  max-width: 60ch;
}

.footer-links {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  display: flex;
  gap: var(--space-3);
  align-items: center;
}

.footer-links a {
  color: var(--color-text-muted);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--color-text); }

/* --------------------------------------------------------------------------
   11. RESPONSIVE — MOBILE FIRST
   -------------------------------------------------------------------------- */

/* Tablet: 768px */
@media (max-width: 768px) {

  .header-inner {
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    gap: var(--space-2) var(--space-4);
    padding: var(--space-3) var(--space-4);
  }

  .header-meta {
    grid-column: 1 / -1;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .stats-inner {
    padding-inline: var(--space-4);
    gap: var(--space-3);
  }

  .stat-value {
    font-size: var(--text-lg);
  }

  .chart-outer,
  .analytics-inner,
  .cards-inner {
    padding-inline: var(--space-4);
  }

  /* Weekday matrix: compress slightly */
  .matrix-cell {
    padding: var(--space-2);
  }

  .data-cell {
    font-size: var(--text-sm);
    min-height: 44px;
  }

  /* Cards: 2 columns on tablet */
  .cards-inner {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    padding-inline: var(--space-4);
  }
}

/* Mobile: 480px */
@media (max-width: 480px) {

  /* Header: single column stack */
  .header-inner {
    grid-template-columns: 1fr;
    grid-template-rows: auto auto auto;
  }

  .brand-name { display: none; }

  /* Stats: 3 columns still work at 480px with smaller values */
  .stats-inner {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-2);
  }

  .stat-value {
    font-size: var(--text-lg);
    min-width: unset;
  }

  /* Period toggle: full width */
  .analytics-header {
    flex-direction: column;
    align-items: flex-start;
  }

  /* Weekday matrix: tight */
  .matrix-header,
  .matrix-row {
    gap: var(--space-1);
  }

  .data-cell {
    font-size: var(--text-xs);
    padding: var(--space-2) var(--space-1);
    min-height: 40px;
  }

  .subtext-cell {
    font-size: 0.65rem;
  }

  /* Cards: single column on mobile */
  .cards-inner {
    grid-template-columns: 1fr;
  }
}

/* Touch: remove hover states that don't apply */
@media (hover: none) {
  .brand-link:hover { opacity: 1; }
  .btn-retry:hover { background: transparent; border-color: var(--color-border); }
  .period-btn:hover { background: transparent; color: var(--color-text-muted); }
  .footer-links a:hover { color: var(--color-text-muted); }
}