/* Study Pill — primitives layer.
 *
 * Reusable components built from tokens.css. Once a screen migrates to these,
 * its bespoke `<style>` block can shrink to layout-only rules. Existing
 * screens keep working unchanged because every primitive uses a unique
 * `.sp-…` prefix that doesn't collide with the legacy class names.
 *
 * Available primitives:
 *   .sp-app-bar           sticky top app bar (back · title · actions)
 *   .sp-bottom-nav        thumb-zone bottom nav (5 tabs, safe-area aware)
 *   .sp-btn / variants    primary, ghost, link, icon
 *   .sp-card              elevated surface
 *   .sp-chip              pill — neutral, accent, success, warn, danger
 *   .sp-toast             ephemeral notification
 *   .sp-empty             empty-state container
 *   .sp-stack             vertical spacing scale
 */
@import url("./tokens.css");

/* ---------- Reset patches that the design wants everywhere ---------- */
.sp-app-bar *,
.sp-bottom-nav *,
.sp-card * { -webkit-tap-highlight-color: transparent; }

/* ---------- App bar ---------- */
.sp-app-bar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: var(--sp-space-3);
  padding: var(--sp-space-3) var(--sp-space-4);
  padding-top: calc(var(--sp-space-3) + env(safe-area-inset-top, 0));
  background: color-mix(in oklch, var(--sp-paper) 88%, transparent);
  backdrop-filter: saturate(1.2) blur(16px);
  -webkit-backdrop-filter: saturate(1.2) blur(16px);
  border-bottom: 1px solid var(--sp-rule-soft);
  flex-wrap: wrap; row-gap: var(--sp-space-2);
}
.sp-app-bar__back {
  flex: 0 0 auto;
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px;
  background: var(--sp-paper-2); color: var(--sp-ink);
  border: 1px solid var(--sp-rule); border-radius: var(--sp-radius-sm);
  text-decoration: none; cursor: pointer;
  font-size: 17px; line-height: 1;
  transition: background var(--sp-dur-fast) ease;
}
.sp-app-bar__back:hover { background: var(--sp-paper-edge); }
.sp-app-bar__back:active { transform: scale(.94); }
.sp-app-bar__title {
  flex: 1; min-width: 0;
  font-family: var(--sp-font-display); font-weight: 600; font-size: 16px;
  color: var(--sp-ink); letter-spacing: -.01em; line-height: 1.25;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  margin: 0;
}
.sp-app-bar__sub {
  font-family: var(--sp-font-mono); font-size: 11px; letter-spacing: .08em;
  color: var(--sp-ink-soft); text-transform: uppercase;
  margin-top: 2px;
}
.sp-app-bar__actions { flex: 0 0 auto; display: flex; gap: var(--sp-space-2); align-items: center; flex-wrap: wrap; }
@media (max-width: 500px) {
  .sp-app-bar__title { flex-basis: calc(100% - 50px); order: 0; }
  .sp-app-bar__actions { order: 1; flex-basis: 100%; justify-content: flex-end; }
  .sp-app-bar__back { order: -1; }
}

/* ---------- Bottom nav ---------- */
.sp-bottom-nav {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 30;
  display: grid; grid-template-columns: repeat(var(--sp-bnav-count, 5), 1fr);
  padding: 6px 4px;
  padding-bottom: calc(6px + env(safe-area-inset-bottom, 0));
  background: color-mix(in oklch, var(--sp-paper) 92%, transparent);
  backdrop-filter: saturate(1.4) blur(20px);
  -webkit-backdrop-filter: saturate(1.4) blur(20px);
  border-top: 1px solid var(--sp-rule-soft);
  transition: transform var(--sp-dur-base) var(--sp-ease-out), opacity var(--sp-dur-base) ease;
}
.sp-bottom-nav.is-hidden { transform: translateY(120%); opacity: 0; pointer-events: none; }
.sp-bottom-nav__btn {
  background: transparent; border: 0; cursor: pointer;
  min-height: 56px; padding: 6px 4px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 2px; border-radius: var(--sp-radius-sm);
  font-family: var(--sp-font-ui); font-size: 11px; font-weight: 600;
  color: var(--sp-ink-soft);
  transition: color var(--sp-dur-fast) ease, background var(--sp-dur-fast) ease, transform 80ms ease;
  position: relative;
}
.sp-bottom-nav__btn:active { transform: scale(.94); }
.sp-bottom-nav__btn[aria-current="page"], .sp-bottom-nav__btn.is-active { color: var(--sp-coral); }
.sp-bottom-nav__btn .ico { font-size: 20px; line-height: 1; }
.sp-bottom-nav__btn .badge {
  position: absolute; top: 6px; right: 22%;
  background: var(--sp-coral); color: #fff;
  font-size: 10px; font-weight: 700;
  min-width: 16px; height: 16px; padding: 0 5px;
  border-radius: 999px;
  display: inline-flex; align-items: center; justify-content: center;
}
@media (min-width: 768px) {
  .sp-bottom-nav { max-width: 560px; left: 50%; transform: translateX(-50%); border-radius: 18px 18px 0 0; border: 1px solid var(--sp-rule-soft); border-bottom: 0; }
  .sp-bottom-nav.is-hidden { transform: translate(-50%, 120%); }
}

/* ---------- Buttons ---------- */
.sp-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 20px; border-radius: var(--sp-radius-sm);
  font-family: var(--sp-font-ui); font-size: 14px; font-weight: 600;
  letter-spacing: .005em; line-height: 1;
  border: 1px solid var(--sp-rule); background: var(--sp-paper); color: var(--sp-ink);
  cursor: pointer; text-decoration: none;
  transition: background var(--sp-dur-fast) ease, border-color var(--sp-dur-fast) ease,
              transform 80ms ease, box-shadow var(--sp-dur-fast) ease;
  min-height: 44px;
}
.sp-btn:hover { border-color: var(--sp-ink-soft); }
.sp-btn:active { transform: translateY(1px); }
.sp-btn[disabled], .sp-btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

.sp-btn--primary {
  background: var(--sp-coral); color: #fff; border-color: var(--sp-coral);
  box-shadow: var(--sp-lift-1);
}
.sp-btn--primary:hover { background: var(--sp-coral-2); border-color: var(--sp-coral-2); transform: translateY(-1px); box-shadow: var(--sp-lift-2); }
.sp-btn--primary:active { transform: translateY(0); }

.sp-btn--ghost { background: transparent; }
.sp-btn--ghost:hover { background: var(--sp-paper-2); }

.sp-btn--icon {
  width: 44px; height: 44px; padding: 0;
  border-radius: 50%;
}

.sp-btn--lg { padding: 14px 26px; font-size: 15px; min-height: 52px; border-radius: var(--sp-radius-md); }
.sp-btn--sm { padding: 8px 14px; font-size: 13px; min-height: 36px; border-radius: var(--sp-radius-xs); }

/* ---------- Card ---------- */
.sp-card {
  background: var(--sp-paper); color: var(--sp-ink);
  border: 1px solid var(--sp-rule-soft);
  border-radius: var(--sp-radius-md);
  padding: var(--sp-space-5) var(--sp-space-6);
  box-shadow: var(--sp-lift-1);
  transition: transform var(--sp-dur-base) var(--sp-ease-out),
              box-shadow var(--sp-dur-base) var(--sp-ease-out),
              border-color var(--sp-dur-base) var(--sp-ease-out);
}
.sp-card--interactive { cursor: pointer; }
.sp-card--interactive:hover { transform: translateY(-2px); box-shadow: var(--sp-lift-2); border-color: var(--sp-rule); }
.sp-card--flat { box-shadow: none; }

/* ---------- Chip ---------- */
.sp-chip {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 5px 10px; border-radius: 999px;
  font-family: var(--sp-font-ui); font-size: 12px; font-weight: 500;
  letter-spacing: .01em;
  background: var(--sp-paper-2); color: var(--sp-ink-2);
  border: 1px solid var(--sp-rule-soft);
  white-space: nowrap;
}
.sp-chip--accent  { background: color-mix(in oklch, var(--sp-coral) 12%, var(--sp-paper)); color: var(--sp-coral-deep); border-color: color-mix(in oklch, var(--sp-coral) 30%, var(--sp-rule)); }
.sp-chip--success { background: var(--sp-pine-soft); color: var(--sp-pine); border-color: color-mix(in oklch, var(--sp-pine) 35%, var(--sp-rule)); }
.sp-chip--warn    { background: var(--sp-amber-soft); color: oklch(45% 0.18 80); border-color: color-mix(in oklch, var(--sp-amber) 35%, var(--sp-rule)); }
.sp-chip--danger  { background: color-mix(in oklch, var(--sp-coral) 14%, var(--sp-paper)); color: var(--sp-coral); border-color: color-mix(in oklch, var(--sp-coral) 30%, var(--sp-rule)); }
.sp-chip--mono    { font-family: var(--sp-font-mono); font-size: 11px; letter-spacing: .06em; text-transform: uppercase; }

/* ---------- Toast ---------- */
.sp-toast {
  position: fixed; left: 50%; bottom: calc(20px + env(safe-area-inset-bottom, 0));
  transform: translateX(-50%) translateY(120%);
  background: var(--sp-ink); color: var(--sp-paper);
  padding: 10px 16px; border-radius: 999px;
  font-family: var(--sp-font-ui); font-size: 13px; font-weight: 500;
  box-shadow: var(--sp-lift-3); z-index: 1100;
  opacity: 0;
  transition: transform var(--sp-dur-slow) var(--sp-ease-out), opacity var(--sp-dur-base) ease;
  max-width: calc(100vw - 32px);
}
.sp-toast.is-show { transform: translateX(-50%) translateY(0); opacity: 1; }

/* ---------- Empty state ---------- */
.sp-empty {
  padding: var(--sp-space-9) var(--sp-space-5);
  text-align: center;
  color: var(--sp-ink-soft);
  font-family: var(--sp-font-display);
  font-size: 17px; line-height: 1.45;
}
.sp-empty .sp-empty__hint {
  display: block; margin-top: var(--sp-space-2);
  font-family: var(--sp-font-mono); font-size: 11px;
  letter-spacing: .1em; text-transform: uppercase;
}

/* ---------- Vertical stack helper ---------- */
.sp-stack { display: flex; flex-direction: column; }
.sp-stack--1 > * + * { margin-top: var(--sp-space-1); }
.sp-stack--2 > * + * { margin-top: var(--sp-space-2); }
.sp-stack--3 > * + * { margin-top: var(--sp-space-3); }
.sp-stack--4 > * + * { margin-top: var(--sp-space-4); }
.sp-stack--5 > * + * { margin-top: var(--sp-space-5); }
.sp-stack--6 > * + * { margin-top: var(--sp-space-6); }

/* ---------- Reduced motion respect ---------- */
@media (prefers-reduced-motion: reduce) {
  .sp-app-bar, .sp-bottom-nav, .sp-btn, .sp-card, .sp-chip, .sp-toast {
    transition: opacity .12s ease;
  }
}