/* ==========================================================================
   Momentum design system ("Direction B", approved 2026-07-19).
   Brand color tokens are injected inline via theme/context_processors.py as
   --brand-* custom properties; this file derives everything from them so a
   brand.json edit re-skins the whole app. No hardcoded brand values.
   ========================================================================== */

:root {
  --ink: var(--brand-text, #1f2333);
  --violet: var(--brand-primary, #6c5ce7);
  --teal: var(--brand-accent, #12c2a9);
  --sun: var(--brand-secondary, #ffd93d);
  --coral: #ff6b6b;
  --paper: var(--brand-bg, #fffdf7);
  --card: #ffffff;
  --muted: #5a5f73;
  --faint: #8a8fa3;
  --line: rgba(31, 35, 51, 0.08);
  --shadow: 0 10px 30px rgba(31, 35, 51, 0.10);
  --shadow-lift: 0 18px 44px rgba(31, 35, 51, 0.14);
  --r-card: 22px;
  --r-pill: 999px;
  --spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* --------------------------------------------------------------------------
   Base
   -------------------------------------------------------------------------- */
html { scroll-behavior: smooth; }
body { -webkit-font-smoothing: antialiased; }

main a { color: var(--violet); }
main a:hover { color: var(--ink); }

h1, h2, h3 { letter-spacing: -0.02em; line-height: 1.15; }
h1 { font-weight: 900; font-size: clamp(1.8rem, 4.5vw, 2.6rem); }
h2 { font-weight: 800; }
h3 { font-weight: 800; }

:focus-visible {
  outline: 3px solid var(--violet);
  outline-offset: 2px;
  border-radius: 6px;
}

/* ambient gradient blobs (fixed, behind everything) */
.blob {
  position: fixed; border-radius: 50%; filter: blur(90px);
  opacity: 0.22; z-index: -1; pointer-events: none;
}
.blob.b1 { width: 44vw; height: 44vw; background: var(--violet); top: -14vw; left: -12vw; animation: blob-drift 28s ease-in-out infinite; }
.blob.b2 { width: 34vw; height: 34vw; background: var(--teal); bottom: -14vw; right: -8vw; animation: blob-drift 34s ease-in-out infinite reverse; }
@keyframes blob-drift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(5vw, 3vh) scale(1.1); }
}

/* --------------------------------------------------------------------------
   Header / nav
   -------------------------------------------------------------------------- */
header.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 84%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}
header.site-header .brand-name { font-weight: 900; letter-spacing: -0.02em; }
header.site-header nav { display: flex; align-items: center; gap: 1.1rem; flex-wrap: wrap; }
header.site-header nav a { color: var(--muted); text-decoration: none; font-weight: 600; font-size: 0.9rem; }
header.site-header nav a:hover { color: var(--violet); }
/* .btn links (e.g. header Sign up) keep white text -- the rules above are more
   specific than plain .btn and were silently overriding it to --muted/--violet,
   both dark against the purple button background (low contrast, hard to read). */
header.site-header nav a.btn,
header.site-header nav a.btn:hover { color: #fff; }
.nav-logout { display: inline; }
.nav-logout button {
  background: none; border: none; color: var(--muted); font: inherit;
  font-weight: 600; font-size: 0.9rem; cursor: pointer; padding: 0;
}
.nav-logout button:hover { color: var(--coral); }
.nav-lang select {
  border: 2px solid var(--line); border-radius: var(--r-pill);
  padding: 0.35rem 0.8rem; font: inherit; font-weight: 600; font-size: 0.82rem;
  background: var(--card); color: var(--muted); cursor: pointer;
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn, button.btn, a.btn {
  display: inline-block; border: none; cursor: pointer; text-decoration: none;
  background: var(--violet); color: #fff; font: inherit; font-weight: 800;
  padding: 0.85rem 1.9rem; border-radius: var(--r-pill); font-size: 1rem;
  box-shadow: 0 8px 24px color-mix(in srgb, var(--violet) 40%, transparent);
  transition: transform 0.18s var(--spring), box-shadow 0.2s;
}
.btn:hover { transform: translateY(-3px) scale(1.03); box-shadow: 0 14px 34px color-mix(in srgb, var(--violet) 50%, transparent); color: #fff; }
.btn:active { transform: translateY(-1px) scale(0.99); }
.btn.alt { background: var(--card); color: var(--ink); border: 2px solid var(--line); box-shadow: var(--shadow); }
.btn.alt:hover { color: var(--violet); }
.btn.teal { background: var(--teal); box-shadow: 0 8px 24px color-mix(in srgb, var(--teal) 40%, transparent); }
.btn.small { padding: 0.55rem 1.2rem; font-size: 0.88rem; }

/* --------------------------------------------------------------------------
   Cards & reveals
   -------------------------------------------------------------------------- */
.card {
  background: var(--card); border-radius: var(--r-card);
  border: 1px solid var(--line); box-shadow: var(--shadow);
  padding: 1.6rem;
}
.card.hoverable { transition: transform 0.25s var(--spring), box-shadow 0.25s; }
.card.hoverable:hover { transform: translateY(-5px); box-shadow: var(--shadow-lift); }

.pop { opacity: 0; transform: translateY(26px) scale(0.97); transition: opacity 0.55s ease, transform 0.55s var(--spring); }
.pop.in { opacity: 1; transform: none; }
.pop.d1 { transition-delay: 0.08s; }
.pop.d2 { transition-delay: 0.16s; }
.pop.d3 { transition-delay: 0.24s; }
.pop.d4 { transition-delay: 0.32s; }

.chip {
  display: inline-block; font-size: 0.7rem; font-weight: 800; letter-spacing: 0.06em;
  padding: 0.28rem 0.7rem; border-radius: var(--r-pill); text-transform: uppercase;
}
.chip.violet { background: color-mix(in srgb, var(--violet) 12%, transparent); color: var(--violet); }
.chip.teal { background: color-mix(in srgb, var(--teal) 14%, transparent); color: color-mix(in srgb, var(--teal) 75%, black); }
.chip.coral { background: color-mix(in srgb, var(--coral) 12%, transparent); color: color-mix(in srgb, var(--coral) 80%, black); }
.chip.sun { background: color-mix(in srgb, var(--sun) 30%, transparent); color: #9c7c00; }

.meter { height: 8px; background: #eef0f6; border-radius: var(--r-pill); overflow: hidden; }
.meter i { display: block; height: 100%; border-radius: var(--r-pill); width: 0;
  background: linear-gradient(90deg, var(--teal), var(--violet));
  transition: width 1.1s cubic-bezier(0.5, 0, 0.3, 1); }

/* --------------------------------------------------------------------------
   Landing page (home.html)
   -------------------------------------------------------------------------- */
.hero {
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 3rem; align-items: center;
  max-width: 1100px; margin: 0 auto; padding: 3.5rem 0 4rem;
}
.hero h1 { font-size: clamp(2.2rem, 5.5vw, 3.7rem); }
.hero .mark { position: relative; white-space: nowrap; }
.hero .mark::before {
  content: ''; position: absolute; inset: 58% -2% -4% -2%;
  background: var(--sun); z-index: -1; border-radius: 6px;
  transform: scaleX(0); transform-origin: left;
  animation: mark-swipe 0.7s 0.7s var(--spring) forwards;
}
@keyframes mark-swipe { to { transform: scaleX(1); } }
.hero .lead { margin-top: 1.3rem; font-size: 1.12rem; color: var(--muted); max-width: 42ch; }
.hero .cta-row { margin-top: 2rem; display: flex; gap: 0.9rem; flex-wrap: wrap; align-items: center; }
.hero .mini-proof { margin-top: 1.5rem; font-size: 0.88rem; color: var(--faint); font-weight: 600; }
.hero .mini-proof b { color: var(--teal); }

.hero-stack { position: relative; min-height: 400px; }
.widget {
  position: absolute; background: var(--card); border-radius: var(--r-card);
  box-shadow: var(--shadow); border: 1px solid var(--line); padding: 1.1rem 1.3rem;
}
.widget .big { font-size: 1.9rem; font-weight: 900; }
.widget small { color: var(--faint); font-weight: 700; }
.w-streak { top: 3%; right: 4%; animation: bob 5s ease-in-out infinite; }
.w-quiz { top: 24%; left: 0; width: min(300px, 80%); animation: bob 6s 0.8s ease-in-out infinite; }
.w-quiz h4 { font-size: 0.92rem; margin: 0 0 0.6rem; }
.w-quiz .opt {
  padding: 0.55rem 0.85rem; border-radius: 12px; border: 2px solid var(--line);
  font-size: 0.83rem; font-weight: 600; margin-top: 0.4rem;
}
.w-quiz .opt.correct { border-color: var(--teal); background: color-mix(in srgb, var(--teal) 9%, transparent); position: relative; }
.w-quiz .opt.correct::after { content: '\2713'; position: absolute; right: 0.8rem; color: var(--teal); font-weight: 900; }
.w-ring { bottom: 5%; right: 2%; display: flex; gap: 1rem; align-items: center; animation: bob 5.5s 0.4s ease-in-out infinite; }
.w-ring svg { width: 70px; height: 70px; transform: rotate(-90deg); }
.w-ring .track { fill: none; stroke: #eef0f6; stroke-width: 9; }
.w-ring .arc { fill: none; stroke: var(--teal); stroke-width: 9; stroke-linecap: round;
  stroke-dasharray: 195.6; stroke-dashoffset: 195.6; }
.w-ring.in .arc { animation: ring-fill 1.5s 0.4s cubic-bezier(0.5, 0, 0.3, 1) forwards; }
@keyframes ring-fill { to { stroke-dashoffset: 43; } }
.w-xp { top: 66%; left: 10%; animation: bob 4.6s 1.2s ease-in-out infinite; font-weight: 800; font-size: 0.88rem; }
.w-xp span { color: var(--violet); }
@keyframes bob { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-11px); } }

.home-section { max-width: 1100px; margin: 0 auto; padding: 3.5rem 0; }
.home-section > h2 { text-align: center; font-size: clamp(1.6rem, 4vw, 2.4rem); font-weight: 900; }
.home-section > .sub { text-align: center; color: var(--faint); font-weight: 600; margin-top: 0.5rem; }
.f-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 1.3rem; margin-top: 2.6rem; }
.f-card { background: var(--card); border-radius: var(--r-card); padding: 1.7rem; box-shadow: var(--shadow);
  border: 1px solid var(--line); transition: transform 0.25s var(--spring), box-shadow 0.25s; }
.f-card:hover { transform: translateY(-6px) rotate(-0.4deg); box-shadow: var(--shadow-lift); }
.f-card .emoji { font-size: 1.9rem; }
.f-card h3 { margin-top: 0.7rem; font-size: 1.08rem; }
.f-card p { color: var(--muted); font-size: 0.92rem; margin-top: 0.45rem; }
.f-card .chip { margin-top: 0.9rem; }

.course-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.3rem; margin-top: 2.6rem; }

/* --------------------------------------------------------------------------
   Dashboard
   -------------------------------------------------------------------------- */
.dash-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.3rem; margin-top: 1.8rem; }
.dash-card { display: flex; flex-direction: column; gap: 0.7rem; text-decoration: none; color: inherit; }
.dash-card h3 { font-size: 1.1rem; }
.dash-card .go { margin-top: auto; font-weight: 800; color: var(--violet); font-size: 0.92rem; }
.dash-card:hover .go::after { content: ' \2192'; }

/* --------------------------------------------------------------------------
   Course outline
   -------------------------------------------------------------------------- */
.outline-hero { display: flex; flex-wrap: wrap; gap: 0.9rem; margin: 1.2rem 0 2rem; }
.outline-domain { margin-top: 2.4rem; }
.outline-domain > h2 {
  font-size: 1.15rem; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--faint); border-bottom: 2px solid var(--line); padding-bottom: 0.6rem;
}
.outline-topic {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r-card);
  box-shadow: var(--shadow); padding: 1.4rem 1.6rem; margin-top: 1.1rem;
  transition: transform 0.25s var(--spring), box-shadow 0.25s;
}
.outline-topic:hover { transform: translateY(-3px); box-shadow: var(--shadow-lift); }
.outline-topic h3 { font-size: 1.05rem; }
.outline-lessons { margin: 0.8rem 0 0; padding: 0; list-style: none; counter-reset: lesson; }
.outline-lessons li { counter-increment: lesson; }
.outline-lessons a {
  display: flex; align-items: center; gap: 0.8rem; padding: 0.55rem 0.6rem;
  text-decoration: none; color: var(--ink); font-weight: 600; font-size: 0.94rem;
  border-radius: 12px; transition: background 0.15s, transform 0.15s var(--spring);
}
.outline-lessons a::before {
  content: counter(lesson); flex: none; width: 26px; height: 26px; border-radius: 50%;
  background: color-mix(in srgb, var(--violet) 10%, transparent); color: var(--violet);
  font-size: 0.75rem; font-weight: 800; display: grid; place-items: center;
}
.outline-lessons a:hover { background: color-mix(in srgb, var(--violet) 6%, transparent); transform: translateX(4px); color: var(--ink); }
.outline-flashcards, .outline-exercises { margin-top: 0.7rem; }
.outline-flashcards a, .outline-exercises a {
  display: inline-block; text-decoration: none; font-weight: 700; font-size: 0.82rem;
  padding: 0.45rem 1rem; border-radius: var(--r-pill); margin: 0.25rem 0.3rem 0 0;
  background: color-mix(in srgb, var(--teal) 12%, transparent);
  color: color-mix(in srgb, var(--teal) 70%, black);
  transition: transform 0.18s var(--spring), box-shadow 0.2s;
}
.outline-exercises a, .outline-flashcards a.outline-ex { background: color-mix(in srgb, var(--sun) 28%, transparent); color: #8a6d00; }
.outline-flashcards a:hover, .outline-exercises a:hover { transform: translateY(-2px) scale(1.04); box-shadow: var(--shadow); }
.outline-empty, .outline-flashcards-empty { color: var(--faint); font-size: 0.88rem; font-weight: 600; }
.outline-simulator a, .outline-glossary a { font-weight: 800; }

/* --------------------------------------------------------------------------
   Lesson reader
   -------------------------------------------------------------------------- */
.lesson-body { max-width: 68ch; font-size: 1.04rem; line-height: 1.75; }
.lesson-body p { margin: 1rem 0; }
.lesson-body h1, .lesson-body h2, .lesson-body h3 { margin-top: 2rem; }
.lesson-body blockquote {
  margin: 1.6rem 0; padding: 1.1rem 1.4rem; border-radius: 16px;
  border-left: 5px solid var(--faint); background: var(--card);
  box-shadow: var(--shadow); font-size: 0.97rem;
}
.lesson-body blockquote.qa-trap { border-left-color: var(--coral); background: color-mix(in srgb, var(--coral) 5%, var(--card)); }
.lesson-body blockquote.qa-numbers { border-left-color: var(--teal); background: color-mix(in srgb, var(--teal) 5%, var(--card)); }
.lesson-body blockquote strong:first-child { display: inline-block; margin-bottom: 0.3rem; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.08em; }
.lesson-fallback-note {
  background: color-mix(in srgb, var(--sun) 24%, transparent); border-radius: 12px;
  padding: 0.7rem 1rem; font-weight: 600; font-size: 0.9rem;
}

/* --------------------------------------------------------------------------
   Quiz & simulator
   -------------------------------------------------------------------------- */
.quiz-question, .simulator-question {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r-card);
  box-shadow: var(--shadow); padding: 1.5rem 1.7rem; margin-top: 1.3rem;
}
.quiz-stem, .simulator-stem { font-weight: 700; font-size: 1.02rem; }
.quiz-choice, .simulator-choice {
  display: flex; gap: 0.7rem; align-items: baseline; padding: 0.65rem 0.9rem;
  border: 2px solid var(--line); border-radius: 14px; margin-top: 0.55rem;
  cursor: pointer; font-size: 0.95rem; transition: border-color 0.15s, background 0.15s, transform 0.15s var(--spring);
}
.quiz-choice:hover, .simulator-choice:hover { border-color: var(--violet); transform: translateX(3px); }
.quiz-choice:has(input:checked), .simulator-choice:has(input:checked) {
  border-color: var(--violet); background: color-mix(in srgb, var(--violet) 7%, transparent);
}
.quiz-choice-key, .simulator-choice-label { font-weight: 900; color: var(--violet); }
.simulator-timer {
  position: sticky; top: 4.2rem; z-index: 10; display: inline-block;
  background: var(--ink); color: #fff; font-weight: 800; border-radius: var(--r-pill);
  padding: 0.5rem 1.2rem; font-variant-numeric: tabular-nums;
}
.simulator-intro { color: var(--muted); }
.quiz-empty, .simulator-empty, .exercise-empty {
  background: var(--card); border: 1px dashed var(--line); border-radius: var(--r-card);
  padding: 1.4rem; color: var(--muted); font-weight: 600;
}

/* results */
.quiz-result-score, .simulator-result-score { font-size: 2.6rem; font-weight: 900; }

/* --------------------------------------------------------------------------
   Exercises: match the pairs & word bank (existing class hooks, re-skinned)
   -------------------------------------------------------------------------- */
.exercise-shell { font-weight: 600; }
.match-instructions, .wordbank-prompt { color: var(--muted); }
.match-board { display: flex; gap: 0.8rem; align-items: flex-start; margin-top: 1rem; }
.match-column { flex: 1; display: flex; flex-direction: column; gap: 0.55rem; }
.match-tile {
  min-height: 44px; padding: 0.7rem 0.85rem; text-align: left; font: inherit;
  font-size: 0.93rem; font-weight: 600; cursor: pointer;
  border: 2px solid var(--line); border-radius: 14px; background: var(--card);
  box-shadow: 0 3px 10px rgba(31, 35, 51, 0.05);
  transition: transform 0.18s var(--spring), border-color 0.15s, background 0.15s, opacity 0.3s;
}
.match-tile:hover { transform: translateY(-2px); border-color: var(--violet); }
.match-tile.selected { border-color: var(--violet); background: color-mix(in srgb, var(--violet) 8%, transparent); transform: scale(1.03); }
.match-tile.matched { opacity: 0.32; border-color: var(--teal); cursor: default; pointer-events: none; transform: scale(0.98); }
.match-tile.wrong { border-color: var(--coral); background: color-mix(in srgb, var(--coral) 8%, transparent); animation: shake 0.35s; }
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); } 50% { transform: translateX(5px); } 75% { transform: translateX(-3px); }
}
.wordbank-blank { font-weight: 800; color: var(--violet); }
.wordbank-options { display: flex; flex-wrap: wrap; gap: 0.55rem; margin-top: 1rem; }
.wordbank-tile {
  min-height: 44px; padding: 0.6rem 1.1rem; font: inherit; font-size: 0.93rem; font-weight: 700;
  cursor: pointer; border: 2px solid var(--line); border-radius: var(--r-pill); background: var(--card);
  box-shadow: 0 3px 10px rgba(31, 35, 51, 0.05);
  transition: transform 0.18s var(--spring), border-color 0.15s, background 0.15s;
}
.wordbank-tile:hover:not(:disabled) { transform: translateY(-2px) scale(1.04); border-color: var(--violet); }
.wordbank-tile.correct { border-color: var(--teal); background: color-mix(in srgb, var(--teal) 10%, transparent); animation: pop-correct 0.4s var(--spring); }
@keyframes pop-correct { 40% { transform: scale(1.12); } }
.wordbank-tile.wrong { border-color: var(--coral); background: color-mix(in srgb, var(--coral) 8%, transparent); opacity: 0.6; animation: shake 0.35s; }
.wordbank-tile.hinted { opacity: 0.35; }
.wordbank-tile:disabled { cursor: default; }
.wordbank-actions { display: flex; gap: 0.8rem; margin-top: 1.1rem; }
.exercise-complete, .exercise-summary {
  margin-top: 1.2rem; padding: 1.3rem 1.5rem; border-radius: var(--r-card);
  background: var(--card); border: 1px solid var(--line); box-shadow: var(--shadow);
}

/* --------------------------------------------------------------------------
   Flashcards
   -------------------------------------------------------------------------- */
.flashcard-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--r-card);
  box-shadow: var(--shadow); padding: 2rem; margin-top: 1.2rem;
}
.flashcard-term { font-size: 1.3rem; font-weight: 900; }
.flashcard-definition { margin-top: 0.9rem; line-height: 1.7; }
.flashcard-plain-english { margin-top: 0.8rem; padding: 0.8rem 1rem; border-radius: 12px;
  background: color-mix(in srgb, var(--sun) 20%, transparent); font-size: 0.94rem; }
.flashcard-actions { display: flex; gap: 0.8rem; margin-top: 1.2rem; flex-wrap: wrap; }
.flashcard-progress { color: var(--faint); font-weight: 700; font-size: 0.85rem; }

/* --------------------------------------------------------------------------
   Forms (login/signup)
   -------------------------------------------------------------------------- */
form.auth-form, .auth-card {
  max-width: 420px; margin: 2rem auto; background: var(--card); border-radius: var(--r-card);
  border: 1px solid var(--line); box-shadow: var(--shadow); padding: 2rem;
}
main input[type="text"], main input[type="password"], main input[type="email"] {
  width: 100%; padding: 0.75rem 1rem; font: inherit; border: 2px solid var(--line);
  border-radius: 14px; margin-top: 0.35rem; box-sizing: border-box;
  transition: border-color 0.15s;
}
main input:focus { border-color: var(--violet); outline: none; }

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
footer.site-footer { color: var(--faint); font-weight: 600; }

/* --------------------------------------------------------------------------
   Motion preferences
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .pop { opacity: 1 !important; transform: none !important; }
  .hero .mark::before { transform: scaleX(1); }
  .w-ring .arc { stroke-dashoffset: 43; }
  .meter i { transition: none; }
}

@media (max-width: 820px) {
  .hero { grid-template-columns: 1fr; padding-top: 1.6rem; }
  .hero-stack { min-height: 360px; margin-top: 0.8rem; }
  .match-board { flex-direction: column; }
}