/* =========================================================================
   Components.

   Deliberately not a card kit. Radius, elevation and weight vary by role, so
   shape tells you what something is: the primary card is large and lifted,
   a list row is flat with a hairline, a chip is small and tight.
   ========================================================================= */

/* --- Buttons ------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.6rem 1.05rem;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: var(--tracking-snug);
  border: 1px solid transparent;
  background: var(--chalk-raised);
  color: var(--ink);
  white-space: nowrap;
  /* Links styled as buttons must not keep a link's underline. */
  text-decoration: none;
  transition: background-color var(--dur) var(--ease-out),
              border-color var(--dur) var(--ease-out),
              color var(--dur) var(--ease-out),
              transform var(--dur-fast) var(--ease-out);
}
.btn:hover:not(:disabled) { background: var(--chalk-sunk); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; }

.btn-primary {
  background: var(--ink);
  color: var(--chalk-raised);
}
.btn-primary:hover:not(:disabled) { background: var(--ink-hover); }

.btn-outline {
  background: transparent;
  border-color: var(--chalk-line-strong);
}
.btn-outline:hover:not(:disabled) { background: var(--chalk-raised); border-color: var(--ink-faint); }

.btn-ghost { background: transparent; color: var(--ink-soft); }
.btn-ghost:hover:not(:disabled) { background: var(--chalk-sunk); color: var(--ink); }

.btn-danger { background: transparent; color: var(--trouble); border-color: transparent; }
.btn-danger:hover:not(:disabled) { background: var(--trouble-wash); }

.btn-lg { padding: 0.8rem 1.5rem; font-size: var(--text-base); border-radius: var(--radius-lg); }
.btn-sm { padding: 0.35rem 0.7rem; font-size: var(--text-xs); }
.btn-block { width: 100%; }

.btn-icon {
  width: 2.25rem; height: 2.25rem;
  /* Centres its own icon, so it works with or without .btn alongside it. */
  display: inline-grid; place-items: center;
  padding: 0;
  border-radius: var(--radius-full);
  color: var(--ink-soft);
}
.btn-icon:hover:not(:disabled) { background: var(--chalk-sunk); color: var(--ink); }
.btn-icon svg { width: 1.1rem; height: 1.1rem; }

/* --- Surfaces ------------------------------------------------------------ */
.card {
  background: var(--chalk-raised);
  border: 1px solid var(--chalk-line);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}
.card-flat { background: transparent; border-color: var(--chalk-line); }
.card-quiet { background: var(--chalk-raised); border: none; }

/* The one place a real shadow is spent. */
.card-feature {
  background: var(--chalk-raised);
  border: 1px solid var(--chalk-line);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-lg);
}

.panel {
  background: var(--chalk-raised);
  border: 1px solid var(--chalk-line);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.panel-head {
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--chalk-line);
  display: flex; align-items: center; justify-content: space-between; gap: var(--space-3);
}
.panel-body { padding: var(--space-5); }

/* --- List rows: flat, separated by hairlines, not boxed in cards --------- */
.rows { border-top: 1px solid var(--chalk-line); }
.row-item {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  width: 100%;
  padding: var(--space-4) var(--space-2);
  border-bottom: 1px solid var(--chalk-line);
  text-align: left;
  background: none;
  transition: background-color var(--dur-fast) var(--ease-out);
}
.row-item:hover { background: var(--chalk-raised); }
/* A column, so a title and its subtitle stack whether they are spans or
   divs. Relying on the caller to set display:block on each child is the kind
   of thing that silently breaks one row somewhere. */
.row-item-body {
  min-width: 0;
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
}
.row-item-title {
  font-weight: 600;
  letter-spacing: var(--tracking-snug);
  max-width: 100%;
}
.row-item-sub {
  font-size: var(--text-sm);
  color: var(--ink-faint);
  line-height: var(--leading-snug);
  max-width: 100%;
}
.row-item[aria-disabled="true"] { opacity: 0.55; cursor: not-allowed; }
.row-item[aria-disabled="true"]:hover { background: none; }

/* --- Chips and tags ------------------------------------------------------ */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: var(--tracking-snug);
  background: var(--chalk-sunk);
  color: var(--ink-soft);
  white-space: nowrap;
}
.chip-brass { background: var(--brass-wash); color: var(--brass-deep); }
.chip-mint  { background: var(--mint-wash); color: var(--mint-deep); }
.chip-quiet { background: var(--quiet-wash); color: var(--quiet-text); }
.chip-trouble { background: var(--trouble-wash); color: var(--trouble); }
.chip-outline { background: transparent; border: 1px solid var(--chalk-line-strong); color: var(--ink-faint); }

/* --- Mastery: a dot and a word, never a score ---------------------------- */
.mastery {
  display: inline-flex; align-items: center; gap: 0.4rem;
  font-size: var(--text-xs); font-weight: 600; color: var(--ink-faint);
  white-space: nowrap;
}
.mastery-dot {
  width: 7px; height: 7px; border-radius: var(--radius-full);
  background: var(--mastery-0);
  flex: none;
}
.mastery[data-state="needs_review"] .mastery-dot { background: var(--mastery-1); }
.mastery[data-state="developing"]   .mastery-dot { background: var(--mastery-2); }
.mastery[data-state="understood"]   .mastery-dot { background: var(--mastery-3); }
.mastery[data-state="mastered"]     .mastery-dot { background: var(--mastery-4); }
.mastery[data-state="mastered"] { color: var(--mastery-4); }

/* A four-segment meter. Reads as a state, not a percentage. */
.mastery-meter { display: inline-flex; gap: 3px; align-items: center; }
.mastery-meter i {
  width: 14px; height: 3px; border-radius: 2px;
  background: var(--chalk-line-strong);
}
.mastery-meter[data-level="1"] i:nth-child(-n+1),
.mastery-meter[data-level="2"] i:nth-child(-n+2),
.mastery-meter[data-level="3"] i:nth-child(-n+3),
.mastery-meter[data-level="4"] i:nth-child(-n+4) { background: var(--mastery-3); }
.mastery-meter[data-level="1"] i:nth-child(-n+1) { background: var(--mastery-1); }
.mastery-meter[data-level="4"] i { background: var(--mastery-4); }

/* --- Progress ------------------------------------------------------------ */
.track {
  height: 4px;
  background: var(--chalk-sunk);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.track > i {
  display: block; height: 100%;
  background: var(--ink-soft);
  border-radius: inherit;
  transition: width var(--dur-slow) var(--ease-out);
}

/* --- Forms --------------------------------------------------------------- */
.field { display: block; }
.field + .field { margin-top: var(--space-4); }
.field-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--ink);
}
/* Both are spans, so they need an explicit block to sit under the field
   rather than trailing off the end of it. */
.field-hint {
  display: block;
  font-size: var(--text-xs);
  color: var(--ink-faint);
  margin-top: var(--space-2);
}
.field-error {
  display: block;
  font-size: var(--text-xs);
  color: var(--trouble);
  margin-top: var(--space-2);
}

.input, .textarea, .select {
  display: block;
  width: 100%;
  padding: 0.6rem 0.8rem;
  background: var(--chalk-raised);
  border: 1px solid var(--chalk-line-strong);
  border-radius: var(--radius-md);
  font-size: var(--text-base);
  transition: border-color var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out);
}
.input::placeholder, .textarea::placeholder { color: var(--ink-ghost); }
.input:hover, .textarea:hover, .select:hover { border-color: var(--ink-ghost); }
.input:focus-visible, .textarea:focus-visible, .select:focus-visible {
  border-color: var(--ink);
  box-shadow: var(--focus-ring);
}
.textarea { min-height: 7rem; resize: vertical; line-height: var(--leading-normal); }
.input[aria-invalid="true"], .textarea[aria-invalid="true"] { border-color: var(--trouble); }

.select {
  appearance: none;
  padding-right: 2rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12'%3E%3Cpath d='M2.5 4.5L6 8l3.5-3.5' fill='none' stroke='%23767f8c' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.7rem center;
  background-size: 12px;
}

/* Segmented control: playback speed, filters, view switches. */
.segmented {
  display: inline-flex;
  padding: 3px;
  gap: 2px;
  background: var(--chalk-sunk);
  border-radius: var(--radius-md);
}
.segmented button {
  padding: 0.3rem 0.6rem;
  border-radius: calc(var(--radius-md) - 2px);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.segmented button:hover { color: var(--ink); }
.segmented button[aria-pressed="true"] {
  background: var(--chalk-raised);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
}

/* --- States -------------------------------------------------------------- */
.empty {
  padding: var(--space-8) var(--space-5);
  text-align: center;
  max-width: 44ch;
  margin-inline: auto;
}
.empty-mark { margin: 0 auto var(--space-5); opacity: 0.9; }
.empty h3 { font-size: var(--text-lg); margin-bottom: var(--space-2); }
.empty p { color: var(--ink-faint); font-size: var(--text-sm); margin-bottom: var(--space-5); }

.notice {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  background: var(--chalk-sunk);
  color: var(--ink-soft);
  border: 1px solid transparent;
}
.notice-trouble { background: var(--trouble-wash); color: var(--trouble-text); border-color: var(--trouble-line); }
.notice-brass { background: var(--brass-wash); color: var(--brass-deep); border-color: var(--brass-line); }
.notice-mint { background: var(--mint-wash); color: var(--mint-deep); border-color: var(--mint-line); }
.notice svg { flex: none; width: 1.05rem; height: 1.05rem; margin-top: 1px; }

/* Skeletons: a slow sweep, not a pulse. Calm while waiting. */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--chalk-sunk) 25%,
    color-mix(in srgb, var(--chalk-sunk) 60%, var(--chalk-raised)) 37%,
    var(--chalk-sunk) 63%
  );
  background-size: 400% 100%;
  border-radius: var(--radius-sm);
  animation: sweep 1.8s var(--ease-in-out) infinite;
}
@keyframes sweep {
  0% { background-position: 100% 50%; }
  100% { background-position: 0 50%; }
}
.skeleton-line { height: 0.7rem; margin-bottom: var(--space-2); }
.skeleton-line:last-child { width: 60%; }
@media (prefers-reduced-motion: reduce) {
  .skeleton { animation: none; }
}

.spinner {
  width: 1rem; height: 1rem;
  border: 2px solid var(--chalk-line-strong);
  border-top-color: var(--ink-soft);
  border-radius: var(--radius-full);
  animation: spin 700ms linear infinite;
  flex: none;
}
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) {
  .spinner { animation-duration: 2.4s; }
}

/* --- Toasts -------------------------------------------------------------- */
.toasts {
  position: fixed;
  left: 50%;
  bottom: calc(var(--miniplayer-height) + var(--space-4));
  transform: translateX(-50%);
  z-index: 80;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  width: min(28rem, calc(100vw - 2rem));
  pointer-events: none;
}
.toast {
  pointer-events: auto;
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  background: var(--toast-bg);
  color: var(--toast-text);
  font-size: var(--text-sm);
  box-shadow: var(--shadow-lg);
  animation: toast-in var(--dur) var(--ease-spring);
}
.toast-trouble { background: var(--toast-trouble-bg); }
.toast button { color: inherit; opacity: 0.7; flex: none; }
.toast button:hover { opacity: 1; }
@keyframes toast-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}

/* --- Modal --------------------------------------------------------------- */
.modal-backdrop {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(16, 20, 31, 0.42);
  backdrop-filter: blur(2px);
  display: flex; align-items: center; justify-content: center;
  padding: var(--space-4);
  animation: fade-in var(--dur) var(--ease-out);
}
.modal {
  width: min(34rem, 100%);
  max-height: min(85vh, 46rem);
  overflow-y: auto;
  background: var(--chalk-raised);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  padding: var(--space-6);
  animation: modal-in var(--dur) var(--ease-spring);
}
.modal h2 { margin-bottom: var(--space-2); }
.modal-actions {
  display: flex; justify-content: flex-end; gap: var(--space-3);
  margin-top: var(--space-6);
}
@keyframes fade-in { from { opacity: 0; } to { opacity: 1; } }
@keyframes modal-in {
  from { opacity: 0; transform: translateY(10px) scale(0.99); }
  to { opacity: 1; transform: none; }
}
@media (max-width: 520px) {
  .modal-backdrop { align-items: flex-end; padding: 0; }
  .modal {
    width: 100%;
    max-height: 88vh;
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    padding: var(--space-5) var(--space-4) var(--space-6);
  }
  .modal-actions { flex-direction: column-reverse; }
  .modal-actions .btn { width: 100%; }
}

/* --- Navigation ---------------------------------------------------------- */
.rail {
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
  padding: var(--space-5) var(--space-4);
  border-right: 1px solid var(--chalk-line);
}
.rail-brand {
  display: flex; align-items: center; gap: var(--space-3);
  padding: var(--space-2);
  font-family: var(--font-serif);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-tight);
}
.rail-nav { display: flex; flex-direction: column; gap: 2px; }
.nav-link {
  display: flex; align-items: center; gap: var(--space-3);
  padding: 0.5rem var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--ink-soft);
  text-decoration: none;
  transition: background-color var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.nav-link:hover { background: var(--chalk-raised); color: var(--ink); }
.nav-link[aria-current="page"] { background: var(--chalk-sunk); color: var(--ink); font-weight: 600; }
.nav-link svg { width: 1.05rem; height: 1.05rem; flex: none; opacity: 0.8; }
.nav-link[aria-current="page"] svg { opacity: 1; }

.rail-foot { margin-top: auto; }

/* Below this the top bar and tab bar take over. Written here rather than in
   base.css so it comes after the `display: flex` above and actually wins. */
@media (max-width: 900px) {
  .rail { display: none; }
}

/* Mobile tab bar */
.tabbar {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 60;
  height: calc(var(--tabbar-height) + env(safe-area-inset-bottom, 0px));
  padding-bottom: env(safe-area-inset-bottom, 0px);
  display: none;
  background: color-mix(in srgb, var(--chalk) 92%, transparent);
  backdrop-filter: blur(12px);
  border-top: 1px solid var(--chalk-line);
}
.tabbar-inner { display: flex; height: var(--tabbar-height); }
.tab {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 3px;
  font-size: var(--text-2xs);
  font-weight: 600;
  color: var(--ink-faint);
  text-decoration: none;
  /* Comfortably thumb-sized. */
  min-height: 44px;
}
.tab svg { width: 1.2rem; height: 1.2rem; }
.tab[aria-current="page"] { color: var(--ink); }
@media (max-width: 900px) { .tabbar { display: block; } }

.topbar {
  display: none;
  position: sticky; top: 0; z-index: 50;
  align-items: center; justify-content: space-between;
  gap: var(--space-3);
  height: var(--header-height);
  padding: 0 var(--space-4);
  background: color-mix(in srgb, var(--chalk) 92%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--chalk-line);
}
.topbar .rail-brand { font-size: var(--text-md); padding: 0; }
@media (max-width: 900px) { .topbar { display: flex; } }

/* --- Avatar -------------------------------------------------------------- */
.avatar {
  width: 2rem; height: 2rem;
  border-radius: var(--radius-full);
  background: var(--chalk-sunk);
  color: var(--ink-soft);
  display: grid; place-items: center;
  font-size: var(--text-xs); font-weight: 700;
  flex: none;
}

/* The appearance control sits in the rail foot beside the account link. */
.theme-toggle {
  width: 100%;
  justify-content: flex-start;
  background: none;
  font-family: inherit;
}

/* -------------------------------------------------------------------------
   Hum, the guide.

   Sits in the bottom corner, above the tab bar and clear of the mini player.
   Quiet by default: a small face and one line. It is the only part of the
   interface that offers to be listened to rather than read, which is the
   point of it in a product used with the screen off.
   ---------------------------------------------------------------------- */
.guide {
  position: fixed;
  right: var(--space-4);
  bottom: var(--space-4);
  z-index: 60;                 /* under the mini player (70), over the page */
  display: flex;
  align-items: flex-end;
  gap: var(--space-2);
  max-width: min(22rem, calc(100vw - var(--space-6)));
  pointer-events: none;        /* the page keeps working around it */
}
.guide > * { pointer-events: auto; }

@media (max-width: 900px) {
  .guide { bottom: calc(var(--tabbar-height) + var(--space-3) + env(safe-area-inset-bottom, 0px)); }
}
/* Step above the mini player when a lesson is running. */
body:has(.miniplayer) .guide { bottom: calc(var(--space-4) + 4.6rem); }
@media (max-width: 900px) {
  body:has(.miniplayer) .guide {
    bottom: calc(var(--tabbar-height) + 4.6rem + env(safe-area-inset-bottom, 0px));
  }
}

.guide-bubble {
  flex: 1;
  min-width: 0;
  padding: var(--space-4);
  border: 1px solid var(--chalk-line);
  border-radius: var(--radius-lg);
  background: var(--chalk-raised);
  box-shadow: var(--shadow-soft, 0 10px 30px rgb(0 0 0 / 0.10));
  transform-origin: bottom right;
  transition: opacity var(--dur) var(--ease-out), transform var(--dur) var(--ease-out);
}
.guide[data-open="false"] .guide-bubble {
  opacity: 0;
  transform: scale(0.94) translateY(6px);
  /* Hidden from the keyboard and screen readers too, not just from sight. */
  visibility: hidden;
  position: absolute;
  right: 3.4rem;
  bottom: 0;
  width: min(20rem, calc(100vw - var(--space-6)));
}

.guide-line {
  margin: 0 0 var(--space-3);
  font-size: var(--text-sm);
  line-height: var(--leading-normal);
  color: var(--ink);
}

.guide-actions {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  justify-content: flex-end;
}

.guide-badge {
  flex: none;
  width: 2.9rem; height: 2.9rem;
  display: grid; place-items: center;
  padding: 0;
  border: 1px solid var(--chalk-line);
  border-radius: var(--radius-full);
  background: var(--chalk-raised);
  color: var(--ink-soft);
  box-shadow: var(--shadow-soft, 0 10px 30px rgb(0 0 0 / 0.10));
  cursor: pointer;
  transition: transform var(--dur-fast) var(--ease-out), border-color var(--dur) var(--ease-out);
}
.guide-badge:hover { border-color: var(--ink-faint); transform: translateY(-1px); }
.guide-badge:active { transform: scale(0.96); }
.guide-badge:focus-visible { box-shadow: var(--focus-ring); }

.guide-face { width: 1.9rem; height: 1.9rem; overflow: visible; }
.guide-face-ring { fill: none; stroke: currentColor; stroke-width: 1.3; opacity: 0.28; }
.guide-eye { fill: currentColor; transform-origin: center; }
.guide-mouth { stroke: var(--brass-deep); stroke-width: 2; }

/* A slow blink, so it reads as attentive rather than animated at you. It
   stops entirely while speaking, when the mouth is doing the work. */
@media (prefers-reduced-motion: no-preference) {
  .guide-eye { animation: guide-blink 7s var(--ease-out) infinite; }
  .guide[data-speaking="true"] .guide-mouth { animation: guide-speak 900ms var(--ease-out) infinite; }
  .guide[data-speaking="true"] .guide-eye { animation: none; }
}
@keyframes guide-blink {
  0%, 92%, 100% { transform: scaleY(1); }
  95% { transform: scaleY(0.12); }
}
@keyframes guide-speak {
  0%, 100% { transform: scaleY(1); }
  50% { transform: scaleY(0.55); }
}
.guide-mouth { transform-origin: center; transform-box: fill-box; }