/* ═══════════════════════════════════════════
   Word Game — Full Responsive Stylesheet (v2)
   适配: 手机竖屏(≤480px) / 横屏(481-768px) / 平板(769-1024px) / 桌面(≥1025px)
   ═══════════════════════════════════════════ */

:root {
  --bg: #0f172a; --card: #111827; --line: #334155; --text: #e5e7eb;
  --muted: #94a3b8; --accent: #22c55e; --accent2: #3b82f6;
  --danger: #ef4444; --warn: #f59e0b;
  /* transition system */
  --t-fast: .15s ease; --t-mid: .25s ease; --t-slow: .4s ease; --t-bounce: .35s cubic-bezier(.34,1.56,.64,1);
  --shadow-sm: 0 1px 3px rgba(0,0,0,.2); --shadow-md: 0 4px 16px rgba(0,0,0,.3); --shadow-lg: 0 8px 32px rgba(0,0,0,.5);

  /* responsive tokens */
  --fs-xxl: 48px; --fs-xl: 32px; --fs-lg: 24px; --fs-md: 18px; --fs-base: 16px; --fs-sm: 14px; --fs-xs: 12px;
  --sp-xs: 6px; --sp-sm: 10px; --sp-md: 16px; --sp-lg: 24px; --sp-xl: 32px;
  --radius: 14px; --radius-card: 18px; --radius-lg: 20px;
  --btn-pad: 10px 16px;
  --game-min-h: 520px;
}

/* ══════ Keyframes ══════ */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes slideUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(34,197,94,.5); }
  70%  { box-shadow: 0 0 0 12px rgba(34,197,94,0); }
  100% { box-shadow: 0 0 0 0 rgba(34,197,94,0); }
}
@keyframes shake {
  0%,100% { transform: translateX(0); }
  10%,30%,50%,70%,90% { transform: translateX(-4px); }
  20%,40%,60%,80% { transform: translateX(4px); }
}
@keyframes popIn {
  from { opacity: 0; transform: scale(.85); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes floatUp {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(-60px) scale(.6); }
}
@keyframes glowPulse {
  0%,100% { box-shadow: 0 0 6px rgba(59,130,246,.3), 0 0 12px rgba(59,130,246,.1); }
  50%     { box-shadow: 0 0 14px rgba(59,130,246,.5), 0 0 24px rgba(59,130,246,.2); }
}
@keyframes blinkCursor {
  0%,100% { border-right-color: var(--accent); }
  50%     { border-right-color: transparent; }
}
@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
@keyframes countUp {
  from { opacity: 0; transform: scale(.5); }
  to   { opacity: 1; transform: scale(1); }
}
@keyframes shimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}
@keyframes cardFlipIn {
  from { transform: rotateY(90deg); opacity: 0; }
  to   { transform: rotateY(0deg); opacity: 1; }
}
@keyframes successBurst {
  0%   { transform: scale(1); box-shadow: 0 0 0 0 rgba(34,197,94,.6); }
  50%  { transform: scale(1.08); box-shadow: 0 0 20px 6px rgba(34,197,94,.3); }
  100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(34,197,94,0); }
}
@keyframes errorFlash {
  0%,100% { background-color: #1f2937; }
  50%     { background-color: rgba(239,68,68,.25); }
}

/* ══════ Reset & Base ══════ */
* { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
  font-family: system-ui, -apple-system, 'Segoe UI', Roboto, Arial, sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  color: var(--text);
  min-height: 100dvh;
  overflow-x: hidden;
}

.btn-skip { display: none; }
body.skip-on .btn-skip { display: inline-block !important; }

/* ══════ Button System ══════ */
button, input, select, textarea { font: inherit; }

button {
  cursor: pointer; border: 0; border-radius: var(--radius);
  padding: var(--btn-pad); background: var(--accent2); color: #fff;
  font-size: var(--fs-sm); font-weight: 600;
  transition: transform var(--t-fast), opacity var(--t-fast), background var(--t-fast), box-shadow var(--t-fast);
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
}
button:hover {
  transform: scale(1.02) translateY(-2px);
  box-shadow: 0 6px 20px rgba(59,130,246,.35);
  opacity: 1;
}
button:active { transform: scale(.98); }
button:disabled { opacity: .55; cursor: not-allowed; transform: none; box-shadow: none; }
button.secondary { background: #475569; }
button.secondary:hover { box-shadow: 0 6px 20px rgba(71,85,105,.35); }
button.danger { background: var(--danger); }
button.danger:hover { box-shadow: 0 6px 20px rgba(239,68,68,.35); }
button.small { padding: 6px 12px; font-size: 12px; border-radius: 8px; }

input {
  width: 100%; padding: 12px; border-radius: var(--radius);
  border: 1px solid var(--line); background: #0b1220; color: #fff;
  font-size: var(--fs-base);
  transition: border-color var(--t-mid), box-shadow var(--t-mid);
}
input:focus { outline: none; border-color: var(--accent2); box-shadow: 0 0 0 3px rgba(59,130,246,.2); }

/* ══════ Auth Pages ══════ */
.auth-page {
  min-height: 100dvh; display: grid; place-items: center;
  padding: var(--sp-md);
}
.auth-card {
  width: min(420px, 100%); background: rgba(17,24,39,.95);
  padding: var(--sp-lg); border-radius: var(--radius-lg);
  border: 1px solid var(--line); box-shadow: var(--shadow-lg);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  animation: fadeIn var(--t-slow) ease;
}
.sub { color: var(--muted); }
.tabs { display: flex; gap: 8px; margin: var(--sp-md) 0; }
.tab { flex: 1; background: #1f2937; }
.tab.active { background: var(--accent2); }
.panel { display: none; gap: 12px; flex-direction: column; }
.panel.active { display: flex; }
.notice { margin-top: var(--sp-md); color: var(--muted); font-size: var(--fs-sm); }

/* ══════ Topbar ══════ */
.topbar {
  display: flex; justify-content: space-between; align-items: center;
  gap: 12px; padding: 12px var(--sp-md);
  border-bottom: 1px solid var(--line);
  background: rgba(17,24,39,.92);
  position: sticky; top: 0; z-index: 10;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}
.topbar h1 { font-size: 20px; margin: 0; white-space: nowrap; }
.top-actions { display: flex; gap: 8px; flex-wrap: wrap; }

/* ══════ Layout (game page) ══════ */
.layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: var(--sp-md);
  padding: var(--sp-md);
  max-width: 1400px;
  margin: 0 auto;
}
.sidebar, .main-panel { display: flex; flex-direction: column; gap: var(--sp-md); }

/* ══════ Cards ══════ */
.card {
  background: rgba(17,24,39,.95); padding: var(--sp-md);
  border-radius: var(--radius-card); border: 1px solid rgba(51,65,85,.6);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-mid), box-shadow var(--t-mid), border-color var(--t-mid);
}
.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--line);
}

/* ══════ Stage Navigation ══════ */
.stage-nav {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--sp-sm);
}
.stage-btn {
  background: #1f2937; font-size: var(--fs-sm);
  padding: 10px 6px; text-align: center;
  transition: all var(--t-mid);
}
.stage-btn.active { background: var(--accent2); box-shadow: 0 2px 12px rgba(59,130,246,.3); }
.stage-btn:hover:not(.active) { background: #2a3748; }

/* ══════ Game Area ══════ */
.game-card { min-height: var(--game-min-h); }

.muted { color: var(--muted); }
.text-sm { font-size: var(--fs-sm); }

/* ══════ Learn Card ══════ */
.learn-card {
  text-align: center; padding: 20px 0;
  animation: slideUp var(--t-slow) ease;
}
.learn-stage-badge {
  display: inline-block; padding: 4px 14px;
  background: rgba(59,130,246,.15); color: var(--accent2);
  border-radius: 999px; font-size: var(--fs-xs); margin-bottom: 20px;
}
.learn-word {
  font-size: var(--fs-xxl); font-weight: 800; margin-bottom: 8px;
  background: linear-gradient(135deg, #60a5fa, #a78bfa, #22c55e);
  background-size: 200% 200%;
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 3s ease infinite;
  position: relative;
  display: inline-block;
}
/* subtle background glow behind the word */
.learn-word::after {
  content: '';
  position: absolute; top: 50%; left: 50%;
  width: 120%; height: 120%;
  background: radial-gradient(ellipse at center, rgba(59,130,246,.15) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  pointer-events: none; z-index: -1;
  filter: blur(20px);
}
.learn-phonetic {
  font-size: var(--fs-md); color: var(--muted); margin-bottom: 4px;
}
.learn-meaning {
  font-size: var(--fs-lg); font-weight: 600; color: var(--accent); margin-bottom: 16px;
}
.learn-sentence {
  font-size: var(--fs-base); color: #cbd5e1;
  background: rgba(17,24,39,.7); padding: 14px 18px;
  border-radius: 12px; border: 1px solid rgba(51,65,85,.5);
  display: inline-block; max-width: 100%; word-break: break-word;
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: border-color var(--t-mid);
}

/* ══════ Quiz (Stage 1) ══════ */
.question {
  font-size: var(--fs-xl); font-weight: 700; margin-bottom: var(--sp-md);
  animation: fadeIn var(--t-mid) ease;
}
.options {
  display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-sm);
}
.option {
  padding: var(--sp-md); font-size: var(--fs-base);
  background: #1f2937; border: 1px solid #334155; border-radius: var(--radius);
  text-align: center; word-break: break-word;
  transition: all var(--t-fast);
}
.option:hover { border-color: #60a5fa; transform: translateY(-2px); box-shadow: 0 4px 12px rgba(59,130,246,.15); }
.option:active { transform: scale(.97); }

/* Animated feedback classes for quiz/typing options */
.option.option-correct {
  background: rgba(34,197,94,.2) !important;
  border-color: var(--accent) !important;
  color: var(--accent) !important;
  animation: pulse .6s ease;
}
.option.option-wrong {
  background: rgba(239,68,68,.2) !important;
  border-color: var(--danger) !important;
  color: var(--danger) !important;
  animation: shake .5s ease;
}

/* ══════ Typing Game (Stage 2) ══════ */
.typing-game {
  position: relative; height: 340px; border-radius: 16px;
  background: #0b1220; border: 1px solid #334155; overflow: hidden;
}
/* Particle pseudo-elements */
.typing-game::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background:
    radial-gradient(2px 2px at 20px 30px, rgba(59,130,246,.2), transparent),
    radial-gradient(2px 2px at 40px 70px, rgba(139,92,246,.15), transparent),
    radial-gradient(1px 1px at 80px 20px, rgba(34,197,94,.2), transparent),
    radial-gradient(2px 2px at 160px 100px, rgba(59,130,246,.15), transparent),
    radial-gradient(1px 1px at 200px 40px, rgba(250,204,21,.15), transparent),
    radial-gradient(2px 2px at 300px 60px, rgba(59,130,246,.1), transparent),
    radial-gradient(1px 1px at 350px 110px, rgba(34,197,94,.15), transparent),
    radial-gradient(1px 1px at 420px 20px, rgba(139,92,246,.15), transparent),
    radial-gradient(2px 2px at 450px 90px, rgba(59,130,246,.1), transparent);
  pointer-events: none; z-index: 1;
}
.typing-game::after {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(180deg, rgba(15,23,42,.3) 0%, transparent 20%, transparent 80%, rgba(15,23,42,.6) 100%);
  pointer-events: none; z-index: 1;
}
.falling {
  position: absolute; padding: 6px 10px;
  background: linear-gradient(135deg, #1d4ed8, #2563eb);
  color: #fff; border-radius: 10px;
  white-space: nowrap; font-size: var(--fs-sm);
  pointer-events: none;
  z-index: 2;
  box-shadow: 0 2px 8px rgba(0,0,0,.4), 0 0 12px rgba(59,130,246,.2);
  transition: opacity var(--t-fast), transform var(--t-fast);
}
/* zombie state for match-missed-but-still-alive card */
.falling.zapped {
  animation: floatUp .5s ease forwards;
}
.typing-input { margin-top: 12px; font-size: var(--fs-base); }
.typing-input.match-hit {
  border-color: var(--accent) !important;
  box-shadow: 0 0 0 3px rgba(34,197,94,.25) !important;
}
.typing-input.match-miss {
  border-color: var(--danger) !important;
  box-shadow: 0 0 0 3px rgba(239,68,68,.25) !important;
  animation: shake .4s ease;
}
#typingStatus {
  min-height: 22px; font-size: var(--fs-sm);
  transition: opacity var(--t-fast);
}

/* ══════ Match Game (Stage 3) ══════ */
.match-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--sp-sm);
  perspective: 800px;
}
.match-card {
  aspect-ratio: 1 / 1.2; max-height: 110px;
  display: grid; place-items: center;
  background: #1f2937; border-radius: var(--radius);
  border: 1px solid #334155; padding: 8px;
  text-align: center; font-size: var(--fs-sm);
  word-break: break-word;
  transition: all var(--t-mid);
  cursor: pointer;
  transform-style: preserve-3d;
  position: relative;
}
.match-card:hover:not(.matched):not(.open) {
  transform: scale(1.05);
  box-shadow: 0 4px 16px rgba(59,130,246,.2);
}
.match-card.open {
  background: linear-gradient(135deg, #0f766e, #14b8a6);
  border-color: #14b8a6;
  box-shadow: 0 2px 12px rgba(20,184,166,.3);
  animation: cardFlipIn var(--t-mid) ease;
}
.match-card.matched {
  background: linear-gradient(135deg, #166534, #22c55e);
  border-color: var(--accent);
  box-shadow: 0 0 18px rgba(34,197,94,.4);
  cursor: default;
  animation: successBurst .6s ease;
}
.match-card.match-miss {
  animation: errorFlash .6s ease;
}

/* ══════ Sentence (Stage 4) ══════ */
.sentence-box {
  font-size: var(--fs-lg); line-height: 1.8;
  background: #0b1220; padding: 18px; border-radius: var(--radius);
  border: 1px solid #334155;
  word-break: break-word;
  animation: fadeIn var(--t-mid) ease;
  position: relative;
}
/* Typing cursor effect on sentence blank */
.sentence-box .blank {
  display: inline-block; min-width: 40px;
  border-bottom: 2px solid var(--accent);
  animation: blinkCursor 1s step-end infinite;
}

/* ══════ Progress Bar ══════ */
.progress-bar-custom {
  width: 100%; height: 8px; background: #334155;
  border-radius: 4px; overflow: hidden;
  position: relative;
}
.progress-fill-custom {
  height: 100%; border-radius: 4px;
  background: linear-gradient(90deg, var(--accent2), var(--accent), var(--warn));
  background-size: 200% 100%;
  animation: gradientShift 2s ease infinite;
  transition: width var(--t-slow);
  position: relative;
}
/* glow at the leading edge */
.progress-fill-custom::after {
  content: '';
  position: absolute; right: 0; top: 0; bottom: 0;
  width: 20px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.4));
  border-radius: 0 4px 4px 0;
}

/* ══════ Utilities ══════ */
.pill {
  display: inline-block; padding: 4px 10px;
  border-radius: 999px; background: #1e293b;
  color: #cbd5e1; font-size: var(--fs-xs);
  border: 1px solid rgba(51,65,85,.4);
  transition: all var(--t-fast);
}
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.space { height: 12px; }
.message-ok { color: #4ade80; animation: fadeIn var(--t-fast) ease; }
.message-bad { color: #f87171; animation: fadeIn var(--t-fast) ease; }
.paywall {
  padding: 28px var(--sp-md); text-align: center;
  background: #1f2937; border-radius: 16px; border: 1px dashed #f59e0b;
  animation: fadeIn var(--t-mid) ease;
}
code { background: #0b1220; padding: 2px 6px; border-radius: 8px; }
#message { margin-top: var(--sp-md); min-height: 24px; transition: opacity var(--t-fast); }
.loading-tip { color: var(--muted); font-size: var(--fs-sm); }

/* ══════ Daily Goal Selector ══════ */
.goal-section { margin-top: 4px; }
.goal-label { font-size: var(--fs-sm); color: var(--muted); margin-bottom: 8px; }
.goal-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px;
  margin-bottom: 8px;
}
.goal-btn {
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 10px 6px; background: #1f2937; border-radius: 10px;
  border: 1px solid var(--line); color: var(--text);
  font-size: 12px; line-height: 1.3;
  transition: all var(--t-fast);
}
.goal-btn:hover { border-color: var(--accent2); transform: translateY(-1px); }
.goal-btn.active {
  background: rgba(59,130,246,.15);
  border-color: var(--accent2);
  color: #fff;
  box-shadow: 0 2px 10px rgba(59,130,246,.2);
}
.goal-btn .goal-emoji { font-size: 20px; }
.goal-btn .goal-name { font-weight: 600; font-size: 13px; }
.goal-btn .goal-num { color: var(--muted); font-size: 11px; }
.goal-btn.active .goal-num { color: var(--accent2); }

.custom-goal {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  margin-bottom: 8px; font-size: var(--fs-sm);
}
.custom-goal input {
  width: 70px !important; text-align: center; padding: 6px;
  font-size: var(--fs-base);
}

.goal-estimate {
  text-align: center; font-size: 12px; margin-bottom: 12px;
}

/* ══════ Goal bar mini (sidebar) ══════ */
.goal-bar-mini {
  display: flex; align-items: center; gap: 6px;
  padding: 8px 10px; background: #1f2937;
  border-radius: 10px; font-size: 12px;
  transition: all var(--t-fast);
}

/* ══════ Streak / Checkin ══════ */
.streak-days {
  font-size: 28px; text-align: center; padding: 10px 0;
}
.streak-bar {
  display: flex; align-items: center; gap: 8px;
  margin-top: 10px; padding: 10px 14px;
  background: #1f2937; border-radius: 10px;
  font-size: 13px; flex-wrap: wrap;
  transition: all var(--t-fast);
}
.streak-bar:hover { background: #2a3748; }
.goal-badge { font-size: 18px; }
.streak-num {
  font-size: 22px; font-weight: 800; color: var(--warn);
  transition: transform var(--t-bounce);
}
.streak-label { color: var(--muted); font-size: var(--fs-sm); }
.checkin-btn {
  transition: all var(--t-mid);
}
.checkin-btn.signed {
  background: rgba(34,197,94,.15);
  border: 1px solid var(--accent);
  color: var(--accent);
}

.milestone-msg {
  text-align: center;
  font-size: var(--fs-sm);
  color: var(--warn);
  padding: 8px 12px;
  margin-top: 8px;
  border-radius: 8px;
  background: rgba(245,158,11,.1);
  border: 1px solid rgba(245,158,11,.3);
  opacity: 0;
  transition: opacity var(--t-mid);
}
.milestone-msg.show {
  opacity: 1;
  animation: slideUp var(--t-bounce);
}

/* ══════ Fire animation for streak ══════ */
@keyframes floatFire {
  0% { transform: translateY(0) scale(1); opacity: 1; }
  50% { transform: translateY(-12px) scale(1.3); opacity: 0.8; }
  100% { transform: translateY(-24px) scale(0.6); opacity: 0; }
}
@keyframes fireFlicker {
  0%, 100% { filter: brightness(1); }
  50% { filter: brightness(1.4) saturate(1.3); }
}
.streak-fire { text-align: center; min-height: 24px; margin-top: 4px; }
.streak-fire.burn .fire-particle {
  display: inline-block;
  animation: floatFire 1.5s ease-out infinite, fireFlicker 0.6s ease-in-out infinite;
}
.streak-fire.burn .fire-particle:nth-child(1) { animation-delay: 0s; }
.streak-fire.burn .fire-particle:nth-child(2) { animation-delay: 0.3s; }
.streak-fire.burn .fire-particle:nth-child(3) { animation-delay: 0.6s; }

/* Num pop animation */
@keyframes numPop {
  0% { transform: scale(1); }
  50% { transform: scale(1.4); color: #fbbf24; }
  100% { transform: scale(1); }
}
.streak-num.popping { animation: numPop 0.5s var(--t-bounce); }

/* ══════ Mistakes / Result Section ══════ */
.mistakes-section {
  margin-top: var(--sp-lg);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: rgba(17,24,39,.7);
  overflow: hidden;
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  animation: fadeIn var(--t-mid) ease;
}
.mistakes-header {
  padding: 12px var(--sp-md);
  background: rgba(239,68,68,.12);
  font-weight: 700; font-size: var(--fs-base);
  color: var(--danger);
  border-bottom: 1px solid var(--line);
}
.mistakes-list {
  display: flex; flex-direction: column;
}
.mistake-row {
  display: flex; gap: 12px; padding: 12px var(--sp-md);
  border-bottom: 1px solid rgba(51,65,85,.4);
  align-items: flex-start;
  transition: background var(--t-fast);
}
.mistake-row:hover { background: rgba(239,68,68,.06); }
.mistake-row:last-child { border-bottom: none; }
.mistake-num {
  width: 26px; height: 26px;
  display: grid; place-items: center;
  background: var(--danger); color: #fff;
  border-radius: 999px; font-size: 12px; font-weight: 700;
  flex-shrink: 0; margin-top: 2px;
}
.mistake-body { flex: 1; min-width: 0; }
.mistake-head {
  display: flex; gap: 8px; align-items: center; flex-wrap: wrap;
  margin-bottom: 2px;
}
.mistake-word {
  font-size: var(--fs-md); font-weight: 700; color: #fff;
}
.mistake-phonetic {
  font-size: var(--fs-xs); color: var(--muted); margin-bottom: 6px;
}
.mistake-line {
  font-size: var(--fs-sm); line-height: 1.6;
  padding: 4px 0;
}
.mistake-label { color: var(--muted); font-size: var(--fs-xs); }
.mistake-correct { color: var(--accent); }
.mistake-wrong { color: var(--danger); }

/* ══════ Lobby-specific: enhanced nav cards ══════ */
.lobby{min-height:100dvh;display:flex;flex-direction:column;align-items:center;padding:40px 16px 60px;gap:24px;overflow-x:hidden}
.lobby-card{width:min(600px,100%);background:rgba(17,24,39,.95);padding:28px;border-radius:20px;border:1px solid var(--line);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);box-shadow:var(--shadow-md);transition:box-shadow var(--t-mid);}
.lobby-card:hover{box-shadow:var(--shadow-lg)}
.lobby-h1{font-size:32px;margin-bottom:4px;background:linear-gradient(135deg,#60a5fa,#a78bfa,#22c55e);background-size:200% 200%;-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;animation:gradientShift 3s ease infinite;}
.lobby-h2{font-size:20px;margin-bottom:16px}
.nav-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:16px}
.nav-btn{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:28px 16px;background:#1f2937;border:1px solid rgba(51,65,85,.5);border-radius:16px;color:#fff;text-decoration:none;transition:all var(--t-mid);cursor:pointer;-webkit-tap-highlight-color:transparent;touch-action:manipulation;position:relative;overflow:hidden;}
.nav-btn::before{content:'';position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.05),transparent);transition:left .6s ease;}
.nav-btn:hover{background:#2a3748;border-color:var(--accent2);transform:translateY(-4px);box-shadow:0 8px 24px rgba(59,130,246,.2);}
.nav-btn:hover::before{left:100%}
.nav-btn .icon{font-size:36px;margin-bottom:8px;transition:transform var(--t-bounce)}
.nav-btn:hover .icon{transform:scale(1.15)}
.nav-btn .label{font-size:15px;font-weight:600}
.nav-btn .desc{font-size:12px;color:var(--muted);margin-top:4px}
.task-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:12px;margin-top:12px}
.task-item{text-align:center;padding:12px 8px;background:#1f2937;border-radius:12px;transition:all var(--t-fast)}
.task-item:hover{transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,.3)}
.task-item .num{font-size:24px;font-weight:700;transition:transform var(--t-bounce)}
.task-item:hover .num{transform:scale(1.1)}
.task-item .lbl{font-size:12px;color:var(--muted)}
.stat-row{display:flex;gap:24px;flex-wrap:wrap;margin-top:8px}
.stat-row span{font-size:14px}
.goal-bar{display:flex;align-items:center;gap:8px;margin-top:10px;padding:10px 14px;background:#1f2937;border-radius:10px;font-size:13px;flex-wrap:wrap;transition:all var(--t-fast)}
.goal-bar:hover{background:#2a3748}
.goal-bar .goal-emoji{font-size:22px}
.goal-bar .goal-text{color:var(--muted)}
.goal-bar .goal-text strong{color:#fff}
.goal-bar .goal-progress{width:90px;height:6px;background:#334155;border-radius:3px;overflow:hidden}
.goal-bar .goal-progress-fill{height:100%;background:linear-gradient(90deg,var(--accent2),var(--accent));border-radius:3px;background-size:200% 100%;animation:gradientShift 2s ease infinite;transition:width var(--t-slow);position:relative}
.goal-bar .goal-progress-fill::after{content:'';position:absolute;right:0;top:0;bottom:0;width:10px;background:linear-gradient(90deg,transparent,rgba(255,255,255,.3));border-radius:0 3px 3px 0}

/* ═══════════════════════════════════════════
   RESPONSIVE BREAKPOINTS
   4 tiers: mobile-portrait / mobile-landscape / tablet / desktop
   ═══════════════════════════════════════════ */

/* ── Tablet: 769-1024px ── */
@media (max-width: 1024px) {
  :root {
    --fs-xxl: 40px; --fs-xl: 28px; --fs-lg: 22px; --fs-md: 16px;
    --game-min-h: 460px;
  }
  .layout { grid-template-columns: 260px 1fr; gap: 12px; padding: 12px; }
  .topbar h1 { font-size: 18px; }
}

/* ── Mobile Landscape & Small Tablet: 481-768px ── */
@media (max-width: 768px) {
  :root {
    --fs-xxl: 36px; --fs-xl: 24px; --fs-lg: 20px; --fs-md: 16px;
    --fs-base: 15px; --fs-sm: 13px; --fs-xs: 11px;
    --sp-md: 12px; --sp-lg: 20px;
    --game-min-h: 400px;
    --radius-card: 16px;
    --btn-pad: 10px 14px;
  }

  .layout {
    grid-template-columns: 1fr;
    padding: 10px; gap: 10px;
  }

  .sidebar { gap: 10px; }
  .sidebar .card { padding: 12px; }

  .topbar { padding: 10px 12px; }
  .topbar h1 { font-size: 16px; }

  .stage-nav { grid-template-columns: repeat(4, 1fr); gap: 6px; }
  .stage-btn { font-size: 11px; padding: 8px 4px; }

  .options { grid-template-columns: 1fr; }

  .match-grid { grid-template-columns: repeat(4, 1fr); gap: 6px; }
  .match-card { font-size: var(--fs-xs); padding: 6px; }

  .typing-game { height: 280px; }
  .falling { font-size: var(--fs-xs); padding: 4px 8px; }

  .learn-word { font-size: var(--fs-xxl); }
  .question { font-size: var(--fs-xl); }
  .sentence-box { font-size: var(--fs-lg); }

  .lobby-h1 { font-size: 24px; }
  .nav-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .nav-btn { padding: 20px 12px; }
  .nav-btn .icon { font-size: 28px; }
  .task-grid { grid-template-columns: repeat(5, 1fr); gap: 6px; }
  .task-item { padding: 8px 4px; }
  .task-item .num { font-size: 18px; }
}

/* ── Phone Portrait: ≤480px ── */
@media (max-width: 480px) {
  :root {
    --fs-xxl: 32px; --fs-xl: 22px; --fs-lg: 18px; --fs-md: 15px;
    --fs-base: 14px; --fs-sm: 12px; --fs-xs: 10px;
    --sp-md: 10px; --sp-lg: 16px;
    --game-min-h: 360px;
    --radius: 10px; --radius-card: 14px; --radius-lg: 16px;
    --btn-pad: 10px 12px;
  }

  .layout { padding: 8px; gap: 8px; }

  .topbar { flex-direction: column; align-items: stretch; gap: 8px; padding: 10px 12px; }
  .topbar h1 { font-size: 15px; text-align: center; }
  .top-actions { justify-content: center; }
  .top-actions button { font-size: 11px; padding: 6px 10px; }

  .stage-nav { grid-template-columns: repeat(2, 1fr); gap: 6px; }
  .stage-btn { font-size: 11px; padding: 10px 6px; }

  .card { padding: 10px; }

  .options { grid-template-columns: 1fr; gap: 8px; }
  .option { padding: 14px; font-size: var(--fs-base); }

  .match-grid { grid-template-columns: repeat(3, 1fr); gap: 6px; }
  .match-card { font-size: 10px; padding: 4px; }

  .typing-game { height: 240px; border-radius: 12px; }
  .falling { font-size: 10px; padding: 3px 6px; border-radius: 6px; }

  .learn-card { padding: 12px 0; }
  .learn-word { font-size: var(--fs-xxl); }
  .learn-meaning { font-size: var(--fs-lg); }
  .learn-sentence { font-size: var(--fs-sm); padding: 10px 14px; }
  .learn-stage-badge { margin-bottom: 12px; }

  .question { font-size: var(--fs-xl); }
  .sentence-box { font-size: var(--fs-base); padding: 14px; }

  .paywall { padding: 20px 12px; }
  .paywall h2 { font-size: var(--fs-lg); }

  .sidebar .card h3 { font-size: var(--fs-md); }

  .pill { font-size: 10px; padding: 3px 8px; }
  .mistake-row { padding: 8px 10px; gap: 8px; }
  .mistake-word { font-size: var(--fs-base); }
  .mistake-line { font-size: var(--fs-xs); }
  .mistakes-header { font-size: var(--fs-sm); padding: 10px; }

  .lobby { padding: 20px 10px 40px; gap: 16px; }
  .lobby-card { padding: 16px; border-radius: 16px; }
  .lobby-h1 { font-size: 20px; }
  .nav-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
  .nav-btn { padding: 20px 12px; }
  .nav-btn .icon { font-size: 28px; }
  .nav-btn .label { font-size: 14px; }
  .task-grid { grid-template-columns: repeat(5, 1fr); gap: 6px; }
  .task-item { padding: 8px 4px; }
  .task-item .num { font-size: 18px; }
  .stat-row { gap: 12px; }
  .stat-row span { font-size: 12px; }
}

/* ── Tiny phones: ≤360px ── */
@media (max-width: 360px) {
  :root {
    --fs-xxl: 28px; --fs-xl: 20px; --fs-lg: 17px;
    --sp-md: 8px;
  }
  .match-grid { grid-template-columns: repeat(3, 1fr); gap: 4px; }
  .match-card { font-size: 9px; padding: 2px; }
  .stage-btn { font-size: 10px; padding: 8px 4px; }
  .typing-game { height: 200px; }
  .nav-grid { grid-template-columns: 1fr; }
  .lobby-h1 { font-size: 20px; }
  .task-grid { grid-template-columns: repeat(3, 1fr); }
  .goal-bar { flex-wrap: wrap; gap: 6px; font-size: 12px; }
}

.announce-box { background: rgba(59,130,246,.1); border: 1px solid rgba(59,130,246,.3); padding: 10px 14px; border-radius: 12px; font-size: 13px; margin-bottom: 8px; }
.announce-bar { background: rgba(59,130,246,.1); border-bottom: 1px solid rgba(59,130,246,.3); padding: 8px 32px 8px 16px; text-align: center; font-size: 13px; position: relative; }
.ann-close { position: absolute; right: 12px; top: 4px; cursor: pointer; font-size: 14px; color: var(--muted); }
.ann-close:hover { color: #fff; }