/* ============================================================
   index.css — Design System & Global Styles
   Versia
   ============================================================ */

/* ── Google Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── Design Tokens ── */
:root {
  /* Brand palette */
  --color-primary:        hsl(243, 80%, 62%);   /* indigo */
  --color-primary-hover:  hsl(243, 80%, 55%);
  --color-primary-dim:    hsl(243, 80%, 62%, .15);
  --color-accent:         hsl(270, 70%, 65%);   /* violet */
  --color-success:        hsl(158, 64%, 42%);
  --color-warning:        hsl(38,  95%, 52%);
  --color-danger:         hsl(0,   80%, 60%);

  /* Surfaces */
  --surface-bg:           hsl(222, 22%, 9%);
  --surface-1:            hsl(222, 20%, 12%);
  --surface-2:            hsl(222, 18%, 16%);
  --surface-3:            hsl(222, 16%, 20%);
  --surface-border:       hsl(222, 16%, 24%);
  --surface-glass:        hsla(222, 20%, 14%, .75);

  /* Text */
  --text-primary:   hsl(220, 20%, 94%);
  --text-secondary: hsl(220, 12%, 62%);
  --text-muted:     hsl(220, 10%, 44%);
  --text-link:      hsl(243, 80%, 72%);

  /* Topbar */
  --topbar-h: 56px;

  /* Sidebar */
  --sidebar-w: 280px;
  --sidebar-collapsed-w: 0px;

  /* Spacing */
  --spacing-xs: .25rem;
  --spacing-sm: .5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border radius */
  --radius-sm: .375rem;
  --radius-md: .625rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:  0 1px  3px hsla(0,0%,0%,.4), 0 1px 2px hsla(0,0%,0%,.3);
  --shadow-md:  0 4px 12px hsla(0,0%,0%,.45);
  --shadow-lg:  0 12px 36px hsla(0,0%,0%,.5);
  --shadow-glow: 0 0 24px hsla(243,80%,62%,.25);

  /* Transitions */
  --ease-default: cubic-bezier(.4, 0, .2, 1);
  --duration-fast: 120ms;
  --duration-normal: 220ms;
  --duration-slow: 380ms;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--surface-bg);
  min-height: 100vh;
  overflow: hidden;
}

a { color: var(--text-link); text-decoration: none; }
a:hover { text-decoration: underline; }

img, svg { display: block; }

button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ── App Root ── */
#app {
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .375rem;
  font-family: var(--font-sans);
  font-size: .875rem;
  font-weight: 500;
  padding: .5rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  transition: background var(--duration-fast) var(--ease-default),
              color     var(--duration-fast) var(--ease-default),
              box-shadow var(--duration-fast) var(--ease-default),
              transform  var(--duration-fast) var(--ease-default);
  white-space: nowrap;
  user-select: none;
}

.btn svg { width: 1em; height: 1em; stroke: currentColor; stroke-width: 2; fill: none; flex-shrink: 0; }

.btn:disabled { opacity: .5; pointer-events: none; }

.btn:active { transform: scale(.97); }

.btn--primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: var(--shadow-sm), 0 0 0 0 hsla(243,80%,62%,0);
}
.btn--primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md), 0 0 16px hsla(243,80%,62%,.35);
}

.btn--secondary {
  background: var(--surface-3);
  color: var(--text-primary);
  border-color: var(--surface-border);
}
.btn--secondary:hover { background: var(--surface-2); }

.btn--ghost {
  color: var(--text-secondary);
}
.btn--ghost:hover { color: var(--text-primary); background: var(--surface-2); }

.btn--sm  { font-size: .8125rem; padding: .3125rem .75rem; }
.btn--lg  { font-size: 1rem; padding: .75rem 1.5rem; }
.btn--full { width: 100%; justify-content: center; }

/* ── Topbar ── */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--topbar-h);
  padding: 0 var(--spacing-lg);
  background: var(--surface-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--surface-border);
  z-index: 100;
  flex-shrink: 0;
}

.topbar__brand {
  display: flex;
  align-items: center;
  gap: .625rem;
}

.topbar__logo {
  width: 28px;
  height: 28px;
  fill: var(--color-primary);
  flex-shrink: 0;
}

.topbar__title,
.topbar__project-name {
  font-size: .9375rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 280px;
}

.topbar__back {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: color var(--duration-fast), background var(--duration-fast);
  flex-shrink: 0;
}
.topbar__back:hover { color: var(--text-primary); background: var(--surface-2); text-decoration: none; }
.topbar__back svg { width: 18px; height: 18px; stroke: currentColor; stroke-width: 2; fill: none; }

.topbar__sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: color var(--duration-fast), background var(--duration-fast);
  flex-shrink: 0;
}
.topbar__sidebar-toggle:hover { color: var(--text-primary); background: var(--surface-2); }
.topbar__sidebar-toggle svg { width: 18px; height: 18px; stroke: currentColor; stroke-width: 2; fill: none; }

.topbar__actions {
  display: flex;
  align-items: center;
  gap: .75rem;
}

/* ── User Chip ── */
.user-chip {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .25rem .625rem .25rem .25rem;
  border-radius: var(--radius-full);
  background: var(--surface-2);
  border: 1px solid var(--surface-border);
}

.user-chip__avatar,
.user-chip__fallback {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  flex-shrink: 0;
}

.user-chip__fallback {
  background: var(--color-primary);
  color: #fff;
  font-size: .75rem;
  font-weight: 700;
  align-items: center;
  justify-content: center;
}

.user-chip__name {
  font-size: .8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  max-width: 140px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ── Spinner ── */
@keyframes spin { to { transform: rotate(360deg); } }

.spinner {
  display: inline-block;
  width: 1em;
  height: 1em;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin .7s linear infinite;
}
.spinner--lg { width: 2.5rem; height: 2.5rem; border-width: 3px; }

/* ── Skeleton loaders ── */
@keyframes shimmer {
  0%   { background-position: -200% 0; }
  100% { background-position:  200% 0; }
}

.skeleton {
  border-radius: var(--radius-sm);
  background: linear-gradient(90deg,
    var(--surface-2) 25%,
    var(--surface-3) 50%,
    var(--surface-2) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s ease-in-out infinite;
}
.skeleton--text   { height: .875rem; border-radius: var(--radius-full); }
.skeleton--title  { height: 1.75rem; width: 60%; border-radius: var(--radius-full); }
.skeleton--avatar { width: 28px; height: 28px; border-radius: 50%; }
.skeleton--icon   { width: 16px; height: 16px; border-radius: var(--radius-sm); }
.skeleton--block  { height: 120px; border-radius: var(--radius-md); margin: 1rem 0; }
.skeleton--line   { height: .8125rem; margin-bottom: .5rem; border-radius: var(--radius-full); }

/* ── Empty / Error states ── */
.empty-state,
.error-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: var(--spacing-2xl) var(--spacing-xl);
  text-align: center;
  color: var(--text-secondary);
}

.empty-state svg,
.error-state svg {
  width: 48px;
  height: 48px;
  stroke: currentColor;
  stroke-width: 1.5;
  fill: none;
  opacity: .5;
}

.error-state svg { color: var(--color-danger); }

.empty-state h2,
.error-state h2 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.empty-state p,
.error-state p { font-size: .875rem; }

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