/* ═══════════════════════════════════════════════════════
   Trader's Lab — Design Tokens
   OKLCH color system, tinted neutrals, 4px spacing scale
   ═══════════════════════════════════════════════════════ */

/* ── Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  /* ── Typography ── */
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'SFMono-Regular', 'Cascadia Code', 'Consolas', monospace;

  /* Type scale */
  --text-xs: 0.6875rem;   /* 11px */
  --text-sm: 0.75rem;     /* 12px */
  --text-base: 0.8125rem; /* 13px */
  --text-lg: 0.875rem;    /* 14px */
  --text-xl: 1rem;        /* 16px */
  --text-2xl: 1.125rem;   /* 18px */
  --text-3xl: 1.25rem;    /* 20px */
  --text-4xl: 2.625rem;   /* 42px */

  /* ── Spacing (4px base) ── */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.5rem;    /* 24px */
  --space-6: 2rem;      /* 32px */
  --space-7: 3rem;      /* 48px */
  --space-8: 4rem;      /* 64px */

  /* ── Colors — OKLCH tinted neutrals (blue hue) ── */
  --color-surface-base:   oklch(0.135 0.012 265);
  --color-surface-raised: oklch(0.165 0.014 265);
  --color-surface-overlay: oklch(0.195 0.015 265);
  --color-surface-hover:  oklch(0.225 0.016 265);

  /* Borders */
  --color-border:      oklch(0.235 0.014 265);
  --color-border-hover: oklch(0.35 0.025 265);

  /* Text */
  --color-text-primary:   oklch(0.83 0.012 265);
  --color-text-secondary: oklch(0.55 0.02 265);
  --color-text-brand:     oklch(0.95 0.01 265);

  /* Semantic */
  --color-accent:      oklch(0.55 0.16 260);
  --color-accent-hover: oklch(0.5 0.18 260);
  --color-up:          oklch(0.62 0.14 155);
  --color-down:        oklch(0.55 0.18 25);
  --color-warning:     oklch(0.75 0.15 75);
  --color-neutral:     oklch(0.55 0.02 265);

  /* ── Backward-compatible aliases (JS inline styles use the old names) ── */
  --bg-base:  var(--color-surface-base);
  --bg-panel: var(--color-surface-raised);
  --bg-hover: var(--color-surface-hover);
  --border:   var(--color-border);
  --text-main: var(--color-text-primary);
  --text:      var(--color-text-primary);
  --text-muted: var(--color-text-secondary);
  --up:       var(--color-up);
  --down:     var(--color-down);
  --accent:   var(--color-accent);
  --neutral:  var(--color-neutral);

  /* Shadows — OKLCH black with alpha */
  --shadow-sm: 0 1px 3px oklch(0 0 0 / 0.4);
  --shadow-md: 0 4px 12px oklch(0 0 0 / 0.5);
  --shadow-lg: 0 8px 24px oklch(0 0 0 / 0.6);

  /* Radii */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;

  /* Motion */
  --ease-in: cubic-bezier(0.4, 0, 1, 1);
  --ease-out: cubic-bezier(0, 0, 0.2, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --duration-fast: 150ms;
  --duration-normal: 200ms;
  --duration-slow: 300ms;
}

/* ── Global resets ── */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

body {
  font-family: var(--font-sans);
  background: var(--color-surface-base);
  color: var(--color-text-primary);
  min-height: 100vh;
  min-height: 100dvh;
}

/* ── Utilities ── */
.num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  text-align: right;
}

.up   { color: var(--color-up); }
.down { color: var(--color-down); }

/* ── Button group ── */
.btn-group {
  display: flex;
  background: var(--color-surface-base);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.btn-group button {
  background: transparent;
  border: none;
  color: var(--color-text-secondary);
  padding: 6px 12px;
  cursor: pointer;
  font-size: var(--text-sm);
  font-weight: 500;
  font-family: var(--font-sans);
  transition: color var(--duration-fast) var(--ease-out);
}

.btn-group button:hover { color: var(--color-text-primary); }
.btn-group button.active { background: var(--color-surface-hover); color: var(--color-text-primary); }

/* ── Spinner ── */
.spinner {
  width: 14px;
  height: 14px;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  display: inline-block;
  animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

/* ── Focus visible ── */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-border-hover); }