/* ============================================================
   StudyForge — design tokens
   Metaphor: raw material -> forged, tempered study tools.
   Ember (warm) = untested / weak. Steel (cool) = reviewing.
   Tempered green = mastered.
   ============================================================ */

:root,
[data-theme="forge"] {
  --ink: #10141c;
  --ink-raised: #171d28;
  --ink-card: #1c2331;
  --blueprint-line: #26314599;
  --paper: #eee9de;
  --paper-dim: #a8a396;
  --ember: #ff6a3d;
  --ember-dim: #ff6a3d33;
  --steel: #5b9bd5;
  --steel-dim: #5b9bd533;
  --tempered: #6fcf97;
  --danger: #ff5c5c;
  --grid-opacity: 0.35;
}

[data-theme="daylight"] {
  --ink: #f4f1e8;
  --ink-raised: #ffffff;
  --ink-card: #ffffff;
  --blueprint-line: #c9c2ac99;
  --paper: #2a2620;
  --paper-dim: #756e5e;
  --ember: #d9622f;
  --ember-dim: #d9622f22;
  --steel: #2f6fa8;
  --steel-dim: #2f6fa822;
  --tempered: #2f8a5c;
  --danger: #c93b3b;
  --grid-opacity: 0.25;
}

[data-theme="midnight"] {
  --ink: #0b0c0e;
  --ink-raised: #131416;
  --ink-card: #17181b;
  --blueprint-line: #2a2c3099;
  --paper: #d8d8d8;
  --paper-dim: #85868a;
  --ember: #c9a15a;
  --ember-dim: #c9a15a2b;
  --steel: #6b7580;
  --steel-dim: #6b75802b;
  --tempered: #6f9c81;
  --danger: #b5605f;
  --grid-opacity: 0.15;
}

[data-theme="contrast"] {
  --ink: #000000;
  --ink-raised: #0d0d0d;
  --ink-card: #000000;
  --blueprint-line: #ffffff55;
  --paper: #ffffff;
  --paper-dim: #d9d9d9;
  --ember: #ffb400;
  --ember-dim: #ffb40044;
  --steel: #66d9ff;
  --steel-dim: #66d9ff44;
  --tempered: #5cff8f;
  --danger: #ff6b6b;
  --grid-opacity: 0.1;
}

:root {
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Source Serif 4', serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius: 6px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  min-height: 100vh;
}

body {
  position: relative;
  overflow-x: hidden;
  transition: background 0.2s ease, color 0.2s ease;
}

[data-theme="contrast"] * {
  border-color: var(--blueprint-line) !important;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

.grid-backdrop {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--blueprint-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--blueprint-line) 1px, transparent 1px);
  background-size: 42px 42px;
  opacity: var(--grid-opacity);
  mask-image: radial-gradient(ellipse at top, black, transparent 75%);
}

.site-header, main, .site-footer, .modal-backdrop {
  position: relative;
  z-index: 1;
}

/* ---------- Header ---------- */

.site-header {
  padding: 2rem clamp(1.25rem, 5vw, 4rem) 1rem;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.header-left { display: flex; flex-direction: column; gap: 0.3rem; }

.header-right {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.wordmark {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.08em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.wordmark-mark { color: var(--ember); font-size: 0.9em; }

.tagline {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--paper-dim);
  margin: 0;
}

.theme-switcher select {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: var(--ink-raised);
  color: var(--paper);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 0.5rem 0.6rem;
  cursor: pointer;
}

#auth-area {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--paper-dim);
}

/* ---------- Layout shell ---------- */

main {
  max-width: 820px;
  margin: 0 auto;
  padding: 1.5rem clamp(1.25rem, 5vw, 4rem) 5rem;
}

.stage { width: 100%; }

/* ---------- Intake / furnace ---------- */

.furnace { margin-top: 3rem; }

.furnace-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 0.75rem;
  line-height: 1.05;
}

.furnace-sub {
  font-family: var(--font-body);
  color: var(--paper-dim);
  font-size: 1.05rem;
  max-width: 52ch;
  margin: 0 0 2rem;
  line-height: 1.6;
}

.input-tabs { display: flex; gap: 0.25rem; margin-bottom: 0.75rem; }

.input-tab {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.03em;
  background: transparent;
  border: 1px solid var(--blueprint-line);
  border-bottom: none;
  color: var(--paper-dim);
  padding: 0.5rem 1rem;
  border-radius: var(--radius) var(--radius) 0 0;
  cursor: pointer;
}

.input-tab.active {
  color: var(--ember);
  border-color: var(--ember-dim);
  background: var(--ink-raised);
}

.input-panel {
  background: var(--ink-raised);
  border: 1px solid var(--blueprint-line);
  border-radius: 0 var(--radius) var(--radius) var(--radius);
}

#source-text {
  width: 100%;
  background: transparent;
  border: none;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  padding: 1.1rem 1.25rem;
  resize: vertical;
  min-height: 200px;
}

#source-text:focus { outline: none; }
#source-text::placeholder { color: var(--paper-dim); opacity: 0.6; }

.dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  min-height: 200px;
  cursor: pointer;
  color: var(--paper-dim);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  text-align: center;
  padding: 1rem;
}

.dropzone-icon { font-size: 1.75rem; color: var(--ember); }

.furnace-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
}

.char-count { font-family: var(--font-mono); font-size: 0.78rem; color: var(--paper-dim); }

.error-msg {
  color: var(--danger);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  margin-top: 0.75rem;
}

/* ---------- Buttons ---------- */

.btn-primary {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.95rem;
  background: var(--ember);
  color: var(--ink);
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: transform 0.12s ease, opacity 0.12s ease;
}

.btn-primary:hover { opacity: 0.88; }
.btn-primary:active { transform: scale(0.98); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-ghost {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: transparent;
  color: var(--paper-dim);
  border: 1px solid var(--blueprint-line);
  padding: 0.55rem 1rem;
  border-radius: var(--radius);
  cursor: pointer;
}

.btn-ghost:hover { color: var(--paper); border-color: var(--paper-dim); }

/* ---------- Loading ---------- */

#loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 50vh;
  text-align: center;
}

.forging-anim { display: flex; flex-direction: column; align-items: center; gap: 1rem; }

.ember-pulse {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--ember) 0%, transparent 70%);
  animation: pulse 1.3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(0.85); opacity: 0.6; }
  50% { transform: scale(1.15); opacity: 1; }
}

#loading-label {
  font-family: var(--font-mono);
  color: var(--paper);
  font-size: 0.95rem;
  margin: 0;
}

.loading-sublabel {
  font-family: var(--font-mono);
  color: var(--paper-dim);
  font-size: 0.78rem;
  margin: 0;
}

/* ---------- Workshop ---------- */

.workshop-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 2rem;
  margin-bottom: 1.5rem;
}

.kit-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.4rem, 3.5vw, 2rem);
  margin: 0;
}

.tab-bar {
  display: flex;
  gap: 0.25rem;
  border-bottom: 1px solid var(--blueprint-line);
  margin-bottom: 2rem;
  overflow-x: auto;
}

.ws-tab {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  background: transparent;
  border: none;
  color: var(--paper-dim);
  padding: 0.75rem 0.8rem;
  cursor: pointer;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
}

.ws-tab.active { color: var(--ember); border-bottom-color: var(--ember); }

.ws-panel { animation: fadein 0.2s ease; }

@keyframes fadein {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Cheat sheet ---------- */

.cheat-sheet {
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-left: 3px solid var(--ember);
  border-radius: var(--radius);
  padding: 1.75rem;
}

#summary-text {
  font-family: var(--font-body);
  font-size: 1.08rem;
  line-height: 1.75;
  margin: 0;
  color: var(--paper);
}

/* ---------- Concept map ---------- */

.panel-hint {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--paper-dim);
  margin: 0 0 1.25rem;
}

.concept-tree, .concept-tree ul { list-style: none; margin: 0; padding: 0; }
.concept-tree > li { margin-bottom: 0.6rem; }
.concept-tree ul { margin-top: 0.6rem; padding-left: 1.5rem; border-left: 1px dashed var(--blueprint-line); }

.concept-node {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}

.gauge {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
  background: var(--ember);
  box-shadow: 0 0 8px 1px var(--ember-dim);
  transition: background 0.4s ease, box-shadow 0.4s ease;
}

.gauge.mastered { background: var(--tempered); box-shadow: 0 0 8px 1px var(--tempered); }
.gauge.steel { background: var(--steel); box-shadow: 0 0 8px 1px var(--steel-dim); }

.concept-node-body { flex: 1; }

.concept-node-title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.95rem;
  margin: 0 0 0.2rem;
}

.concept-node-desc {
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--paper-dim);
  margin: 0;
  line-height: 1.5;
}

/* ---------- Flashcards ---------- */

.flash-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.25rem;
}

.flash-position { font-family: var(--font-mono); font-size: 0.82rem; color: var(--paper-dim); }

.flashcard { perspective: 1200px; height: 260px; cursor: pointer; margin: 0 auto; }

.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.5s;
  transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner { transform: rotateY(180deg); }

.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}

.flashcard-front { border-top: 3px solid var(--steel); }
.flashcard-back { border-top: 3px solid var(--ember); transform: rotateY(180deg); }

.flashcard-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--paper-dim);
  margin-bottom: 0.75rem;
}

.flashcard-face p { font-family: var(--font-body); font-size: 1.15rem; line-height: 1.5; margin: 0; }

.flash-hint {
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--paper-dim);
  margin-top: 0.9rem;
}

/* ---------- Quiz ---------- */

.quiz-progress { font-family: var(--font-mono); font-size: 0.78rem; color: var(--paper-dim); margin-bottom: 1rem; }

.quiz-question {
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.quiz-question-concept {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--steel);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: 0 0 0.6rem;
}

.quiz-question-text { font-family: var(--font-body); font-size: 1.15rem; margin: 0 0 1.25rem; line-height: 1.5; }

.quiz-option {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--ink-raised);
  border: 1px solid var(--blueprint-line);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 1rem;
  padding: 0.8rem 1rem;
  border-radius: var(--radius);
  margin-bottom: 0.6rem;
  cursor: pointer;
}

.quiz-option:hover { border-color: var(--paper-dim); }
.quiz-option.correct { border-color: var(--tempered); background: color-mix(in srgb, var(--tempered) 15%, transparent); }
.quiz-option.incorrect { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 15%, transparent); }
.quiz-option:disabled { cursor: default; }

.quiz-feedback { margin-top: 1.25rem; padding-top: 1.25rem; border-top: 1px dashed var(--blueprint-line); }
.quiz-feedback-loading { font-family: var(--font-mono); font-size: 0.85rem; color: var(--paper-dim); }
.quiz-feedback h3 { font-family: var(--font-display); font-size: 0.95rem; color: var(--ember); margin: 0 0 0.5rem; }
.quiz-feedback p { font-family: var(--font-body); font-size: 1rem; line-height: 1.6; margin: 0 0 0.75rem; }
.quiz-feedback .analogy { font-style: italic; color: var(--paper-dim); }

.quiz-next-btn { margin-top: 1rem; }

.quiz-complete { text-align: center; padding: 2.5rem 1rem; }
.quiz-complete h2 { font-family: var(--font-display); margin-bottom: 0.5rem; }
.quiz-complete p { font-family: var(--font-mono); color: var(--paper-dim); margin-bottom: 1.5rem; }

/* ---------- Short answer ---------- */

.short-answer-item {
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
}

.short-answer-question {
  font-family: var(--font-body);
  font-size: 1.08rem;
  line-height: 1.5;
  margin: 0 0 1rem;
}

.short-answer-item textarea {
  width: 100%;
  background: var(--ink-raised);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 0.98rem;
  padding: 0.8rem;
  resize: vertical;
  min-height: 90px;
}

.short-answer-item textarea:focus { outline: none; border-color: var(--paper-dim); }

.short-answer-submit { margin-top: 0.85rem; }

.short-answer-feedback {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--blueprint-line);
  font-family: var(--font-body);
  font-size: 0.98rem;
  line-height: 1.6;
}

.verdict-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  margin-bottom: 0.6rem;
}

.verdict-correct { background: color-mix(in srgb, var(--tempered) 20%, transparent); color: var(--tempered); }
.verdict-partial { background: color-mix(in srgb, var(--ember) 20%, transparent); color: var(--ember); }
.verdict-incorrect { background: color-mix(in srgb, var(--danger) 20%, transparent); color: var(--danger); }

/* ---------- Ask tab ---------- */

.ask-thread { display: flex; flex-direction: column; gap: 1rem; margin-bottom: 1.25rem; }

.ask-item { display: flex; flex-direction: column; gap: 0.5rem; }

.ask-question {
  align-self: flex-end;
  max-width: 85%;
  background: var(--ember-dim);
  border: 1px solid var(--ember-dim);
  border-radius: var(--radius);
  padding: 0.7rem 1rem;
  font-family: var(--font-body);
  font-size: 0.98rem;
}

.ask-answer {
  align-self: flex-start;
  max-width: 85%;
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  font-family: var(--font-body);
  font-size: 0.98rem;
  line-height: 1.6;
}

.ask-form { display: flex; gap: 0.6rem; }

.ask-form input {
  flex: 1;
  background: var(--ink-raised);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 1rem;
  padding: 0.75rem 1rem;
}

.ask-form input:focus { outline: none; border-color: var(--paper-dim); }

.ask-loading { font-family: var(--font-mono); font-size: 0.8rem; color: var(--paper-dim); }

/* ---------- History ---------- */

.history-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-top: 2rem;
  margin-bottom: 1.5rem;
}

.history-list { list-style: none; margin: 0; padding: 0; }

.history-item {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  margin-bottom: 0.75rem;
  cursor: pointer;
}

.history-item:hover { border-color: var(--paper-dim); }

.history-item-title { font-family: var(--font-display); font-weight: 500; font-size: 1rem; margin: 0 0 0.3rem; }

.history-item-meta { font-family: var(--font-mono); font-size: 0.72rem; color: var(--paper-dim); margin: 0 0 0.4rem; }

.history-item-preview {
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--paper-dim);
  margin: 0;
  line-height: 1.5;
}

.history-delete {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  background: transparent;
  border: 1px solid var(--blueprint-line);
  color: var(--paper-dim);
  border-radius: var(--radius);
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  flex-shrink: 0;
}

.history-delete:hover { color: var(--danger); border-color: var(--danger); }

/* ---------- Auth modal ---------- */

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  z-index: 10;
}

.modal {
  background: var(--ink-raised);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  padding: 1.75rem;
  width: 100%;
  max-width: 380px;
}

.modal-tabs { display: flex; gap: 0.25rem; margin-bottom: 1.25rem; }

.modal-tab {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  background: transparent;
  border: 1px solid var(--blueprint-line);
  color: var(--paper-dim);
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius);
  cursor: pointer;
}

.modal-tab.active { color: var(--ember); border-color: var(--ember-dim); }

.modal-title { font-family: var(--font-display); font-size: 1.3rem; margin: 0 0 0.4rem; }

.modal-sub { font-family: var(--font-body); font-size: 0.88rem; color: var(--paper-dim); margin: 0 0 1.25rem; line-height: 1.5; }

.field-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--paper-dim);
  margin: 0.75rem 0 0.3rem;
}

#auth-form input {
  width: 100%;
  background: var(--ink-card);
  border: 1px solid var(--blueprint-line);
  border-radius: var(--radius);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 0.98rem;
  padding: 0.65rem 0.8rem;
}

#auth-form input:focus { outline: none; border-color: var(--paper-dim); }

.modal-actions { display: flex; justify-content: flex-end; gap: 0.6rem; margin-top: 1.5rem; }

/* ---------- Footer ---------- */

.site-footer {
  text-align: center;
  padding: 2rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--paper-dim);
}

/* ---------- Responsive ---------- */

@media (max-width: 560px) {
  .flashcard { height: 220px; }
  .workshop-header { flex-direction: column; align-items: flex-start; }
  .site-header { flex-direction: column; }
  .ask-question, .ask-answer { max-width: 100%; }
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  .ember-pulse { animation: none; }
  .flashcard-inner { transition: none; }
  .ws-panel { animation: none; }
}