/* ==========================================================================
   Từ Vựng Tiếng Anh Cho Bé
   Ý tưởng thị giác: một bộ thẻ học (flashcard) trong lớp học sáng sủa.
   Thẻ to, bo tròn, có gờ dưới dày như thẻ giấy cứng — bấm vào là thẻ "lún"
   xuống. Cỡ chạm lớn vì ngón tay trẻ con.
   Cố ý chỉ có một tông sáng: đây là app dùng ban ngày, và giữ CSS gọn.
   ========================================================================== */

:root {
  --cream:     #fff8ef;
  --cream-2:   #ffefdc;
  --ink:       #143642;
  --ink-soft:  #4a6572;
  --teal:      #10808f;
  --teal-dark: #0b5f6b;
  --amber:     #f5a524;
  --amber-dark:#d98a0b;
  --green:     #2fa84f;
  --green-dark:#218038;
  --coral:     #f0563a;
  --coral-dark:#c93d24;
  --card:      #ffffff;
  --edge:      #e8ddcb;

  --r-lg: 26px;
  --r-md: 18px;
  --r-sm: 12px;

  --font: "Baloo 2", "Segoe UI", system-ui, -apple-system, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  font-family: var(--font);
  font-weight: 600;
  color: var(--ink);
  background: var(--cream);
  background-image: radial-gradient(circle at 12% 8%, var(--cream-2) 0, transparent 42%),
                    radial-gradient(circle at 88% 92%, var(--cream-2) 0, transparent 42%);
  overscroll-behavior: none;
  -webkit-tap-highlight-color: transparent;
}

button { font-family: inherit; font-weight: 700; cursor: pointer; border: 0; }

:focus-visible { outline: 3px solid var(--teal); outline-offset: 3px; }

/* ---------------------------------------------------------------- khung -- */
.wrap {
  max-width: 34rem;
  margin-inline: auto;
  padding: 1rem 1rem 2rem;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

.screen { display: none; flex-direction: column; flex: 1; }
.screen.active { display: flex; }

/* --------------------------------------------------------------- nút to -- */
/* Thẻ có gờ dưới dày, bấm là lún xuống — cảm giác bấm thẻ giấy cứng. */
.chunky {
  border-radius: var(--r-md);
  border-bottom: 6px solid var(--shade, var(--teal-dark));
  background: var(--tone, var(--teal));
  color: #fff;
  transition: transform 0.12s ease, filter 0.12s ease;
}
.chunky:active { transform: translateY(4px); border-bottom-width: 2px; }
.chunky:disabled { filter: grayscale(0.5) opacity(0.55); cursor: default; }

.t-teal  { --tone: var(--teal);  --shade: var(--teal-dark); }
.t-amber { --tone: var(--amber); --shade: var(--amber-dark); }
.t-green { --tone: var(--green); --shade: var(--green-dark); }
.t-coral { --tone: var(--coral); --shade: var(--coral-dark); }

/* ============================== MÀN HÌNH CHÍNH =========================== */
.home-head { text-align: center; margin: 0.75rem 0 1.25rem; }

.home-title {
  font-size: clamp(1.9rem, 1.4rem + 2.4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.1;
  margin: 0 0 0.25rem;
  letter-spacing: -0.02em;
}
.home-title span { color: var(--teal); }

.home-sub { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }

.section-label {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 0.5rem 0.25rem;
}

/* chọn cấp độ */
.levels { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.6rem; margin-bottom: 1.5rem; }

.level-btn {
  background: var(--card);
  border: 2px solid var(--edge);
  border-radius: var(--r-md);
  padding: 0.7rem 0.4rem;
  text-align: center;
  color: var(--ink-soft);
  transition: transform 0.12s ease, border-color 0.12s ease, background 0.12s ease;
}
.level-btn .lv-emoji { display: block; font-size: 1.5rem; line-height: 1.2; }
.level-btn .lv-name  { display: block; font-size: 0.95rem; font-weight: 800; }
.level-btn .lv-age   { display: block; font-size: 0.72rem; font-weight: 600; opacity: 0.75; }
.level-btn:active { transform: scale(0.96); }
.level-btn[aria-pressed="true"] {
  background: var(--teal);
  border-color: var(--teal-dark);
  color: #fff;
}

/* chọn chế độ */
.modes { display: flex; flex-direction: column; gap: 0.8rem; }

.mode-btn {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1rem 1.1rem;
  text-align: left;
  width: 100%;
}
.mode-btn .m-emoji { font-size: 2.1rem; line-height: 1; flex-shrink: 0; }
.mode-btn .m-name  { display: block; font-size: 1.2rem; font-weight: 800; }
.mode-btn .m-desc  { display: block; font-size: 0.82rem; font-weight: 600; opacity: 0.92; }

.home-foot {
  margin-top: auto;
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.78rem;
  color: var(--ink-soft);
}
.home-foot b { color: var(--teal); }

/* ================================ THANH TRÊN ============================= */
.bar {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-bottom: 1rem;
}

.back-btn {
  background: var(--card);
  border: 2px solid var(--edge);
  border-radius: 999px;
  width: 2.6rem;
  height: 2.6rem;
  font-size: 1.1rem;
  color: var(--ink);
  flex-shrink: 0;
  transition: transform 0.12s ease;
}
.back-btn:active { transform: scale(0.92); }

.bar-title { font-size: 1rem; font-weight: 800; margin: 0; flex: 1; }
.bar-meta  { font-size: 0.85rem; font-weight: 700; color: var(--ink-soft); }

.progress {
  height: 8px;
  background: var(--edge);
  border-radius: 999px;
  overflow: hidden;
  margin-bottom: 1rem;
}
.progress > i {
  display: block;
  height: 100%;
  background: var(--teal);
  border-radius: 999px;
  transition: width 0.3s ease;
}

/* ================================= HỌC TẬP ============================== */
.flash {
  background: var(--card);
  border: 2px solid var(--edge);
  border-bottom-width: 8px;
  border-radius: var(--r-lg);
  padding: 1.5rem 1.25rem;
  text-align: center;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.5rem;
  animation: cardIn 0.32s cubic-bezier(0.2, 0.9, 0.3, 1.3);
}

@keyframes cardIn {
  from { opacity: 0; transform: translateY(14px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}

.flash-topic {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--amber-dark);
}

.flash-emoji {
  font-size: clamp(4.5rem, 3rem + 14vw, 7rem);
  line-height: 1.05;
  cursor: pointer;
  user-select: none;
  transition: transform 0.15s ease;
}
.flash-emoji:active { transform: scale(0.9); }

.flash-en {
  font-size: clamp(2rem, 1.4rem + 3.2vw, 2.8rem);
  font-weight: 800;
  color: var(--teal);
  margin: 0;
  letter-spacing: -0.01em;
}

.flash-vi { font-size: 1.15rem; font-weight: 700; color: var(--ink); margin: 0; }

.flash-ex {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-soft);
  font-style: italic;
  margin: 0.35rem 0 0;
}

.speak-row { display: flex; gap: 0.6rem; justify-content: center; margin-top: 0.9rem; flex-wrap: wrap; }
.speak-btn { padding: 0.55rem 1rem; font-size: 0.9rem; border-radius: 999px; }

.nav-row { display: flex; gap: 0.7rem; margin-top: 1rem; }
.nav-row .chunky { flex: 1; padding: 0.9rem; font-size: 1rem; }

/* ========================== LUYỆN TẬP & THI CỬ ========================== */
.q-prompt {
  text-align: center;
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink-soft);
  margin: 0 0 0.75rem;
}

.q-stage {
  background: var(--card);
  border: 2px solid var(--edge);
  border-bottom-width: 8px;
  border-radius: var(--r-lg);
  padding: 1.25rem 1rem;
  text-align: center;
  margin-bottom: 1rem;
  animation: cardIn 0.3s cubic-bezier(0.2, 0.9, 0.3, 1.3);
}

.q-emoji { font-size: clamp(4rem, 2.5rem + 13vw, 6rem); line-height: 1.05; }
.q-word  { font-size: clamp(1.8rem, 1.3rem + 2.6vw, 2.4rem); font-weight: 800; color: var(--teal); }
.q-vi    { font-size: 1.4rem; font-weight: 800; color: var(--ink); }

/* dạng điền chữ thiếu */
.q-blank { font-size: clamp(1.9rem, 1.4rem + 2.6vw, 2.5rem); font-weight: 800; letter-spacing: 0.12em; color: var(--ink); }
.q-blank u { color: var(--coral); text-decoration: none; }

.q-listen {
  background: var(--teal);
  color: #fff;
  border-radius: 999px;
  width: 5rem;
  height: 5rem;
  font-size: 2rem;
  margin: 0.5rem auto 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 5px solid var(--teal-dark);
  transition: transform 0.12s ease;
}
.q-listen:active { transform: translateY(3px); }

/* đáp án */
.answers { display: grid; gap: 0.6rem; }
.answers.grid-2 { grid-template-columns: 1fr 1fr; }

.ans {
  background: var(--card);
  border: 2px solid var(--edge);
  border-bottom-width: 6px;
  border-radius: var(--r-md);
  padding: 0.95rem 0.8rem;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--ink);
  transition: transform 0.12s ease, background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.ans .a-emoji { font-size: 2.6rem; line-height: 1.1; display: block; }
.ans:active { transform: translateY(3px); }

.ans.correct {
  background: var(--green);
  border-color: var(--green-dark);
  color: #fff;
  animation: pulseIn 0.35s ease;
}
.ans.wrong {
  background: var(--coral);
  border-color: var(--coral-dark);
  color: #fff;
  animation: shake 0.35s ease;
}
.ans:disabled { cursor: default; }

@keyframes pulseIn {
  0%   { transform: scale(1); }
  45%  { transform: scale(1.07); }
  100% { transform: scale(1); }
}
@keyframes shake {
  0%,100% { transform: translateX(0); }
  25% { transform: translateX(-7px); }
  75% { transform: translateX(7px); }
}

/* băng phản hồi ở chế độ luyện */
.feedback {
  margin-top: 0.9rem;
  border-radius: var(--r-md);
  padding: 0.85rem 1rem;
  text-align: center;
  font-weight: 700;
  animation: cardIn 0.25s ease;
}
.feedback.ok  { background: #e4f6e8; color: var(--green-dark); border: 2px solid #b9e5c4; }
.feedback.no  { background: #ffe9e4; color: var(--coral-dark); border: 2px solid #ffc9bd; }
.feedback .fb-word { font-size: 1.15rem; display: block; }
.feedback .fb-next { margin-top: 0.65rem; width: 100%; padding: 0.8rem; font-size: 1rem; }

.hud { display: flex; justify-content: space-between; font-size: 0.88rem; font-weight: 700; margin-bottom: 0.6rem; }
.hud .streak { color: var(--amber-dark); }
.hud .timer  { color: var(--ink-soft); }
.hud .timer.low { color: var(--coral); }

/* ================================ KẾT QUẢ =============================== */
.result {
  text-align: center;
  background: var(--card);
  border: 2px solid var(--edge);
  border-bottom-width: 8px;
  border-radius: var(--r-lg);
  padding: 1.75rem 1.25rem;
  animation: cardIn 0.35s cubic-bezier(0.2, 0.9, 0.3, 1.3);
}
.result-emoji { font-size: 4rem; line-height: 1.1; }
.result-title { font-size: 1.5rem; font-weight: 800; margin: 0.35rem 0; }
.result-score { font-size: 2.6rem; font-weight: 800; color: var(--teal); margin: 0.25rem 0; }
.result-note  { color: var(--ink-soft); margin: 0 0 0.5rem; font-size: 0.95rem; }
.stars { font-size: 1.9rem; letter-spacing: 0.15em; }
.record { font-size: 0.85rem; color: var(--amber-dark); font-weight: 700; }

.result-actions { display: flex; flex-direction: column; gap: 0.7rem; margin-top: 1.25rem; }
.result-actions .chunky { padding: 0.9rem; font-size: 1.05rem; }

/* ôn lại từ sai */
.missed { margin-top: 1.25rem; text-align: left; }
.missed h3 { font-size: 0.95rem; margin: 0 0 0.5rem; color: var(--ink-soft); }
.missed ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 0.4rem; }
.missed li {
  display: flex; align-items: center; gap: 0.6rem;
  background: var(--cream-2);
  border-radius: var(--r-sm);
  padding: 0.5rem 0.7rem;
  font-size: 0.95rem;
}
.missed .m-e { font-size: 1.5rem; }
.missed .m-en { font-weight: 800; color: var(--teal-dark); }
.missed .m-vi { color: var(--ink-soft); font-weight: 600; margin-left: auto; font-size: 0.85rem; }

@media (prefers-reduced-motion: reduce) {
  .flash, .q-stage, .result, .feedback { animation: none; }
  .ans.correct, .ans.wrong { animation: none; }
  .chunky, .ans, .level-btn, .back-btn, .flash-emoji { transition: none; }
}