/* ==========================================================================
   Quantu v2.2 - Design System, Multi-Device Responsive Architecture & PWA UI
   Mobile, Tablet & Desktop Monitors | Glassmorphism 2.0 | Tabular Precision
   ========================================================================== */

:root {
  /* Paleta Base - Cyber Dark Quantum */
  --bg-dark: #06080f;
  --bg-surface: #0c101d;
  --bg-card: rgba(16, 21, 36, 0.78);
  --bg-card-solid: #111626;
  --bg-card-hover: rgba(25, 33, 54, 0.9);
  --bg-elevated: rgba(28, 36, 58, 0.72);
  --bg-glass: rgba(255, 255, 255, 0.045);
  --border-subtle: rgba(255, 255, 255, 0.09);
  --border-highlight: rgba(255, 255, 255, 0.16);
  --border-glow: rgba(0, 245, 212, 0.35);

  /* Acentos Vibrantes */
  --cyan-primary: #00f5d4;
  --cyan-secondary: #00bbf9;
  --cyan-glow: rgba(0, 245, 212, 0.38);
  --purple-accent: #7928ca;
  --purple-glow: rgba(121, 40, 202, 0.38);
  --pink-neon: #ff007a;
  --pink-glow: rgba(255, 0, 122, 0.38);
  --amber-gold: #ffb703;
  --amber-glow: rgba(255, 183, 3, 0.38);
  --emerald-success: #10b981;
  --emerald-glow: rgba(16, 185, 129, 0.45);
  --rose-danger: #f43f5e;
  --rose-glow: rgba(244, 63, 94, 0.45);

  /* Cores por Nível de Dificuldade */
  --diff-easy: #10b981;
  --diff-easy-bg: rgba(16, 185, 129, 0.12);
  --diff-medium: #00f5d4;
  --diff-medium-bg: rgba(0, 245, 212, 0.12);
  --diff-hard: #f97316;
  --diff-hard-bg: rgba(249, 115, 22, 0.12);
  --diff-super: #f43f5e;
  --diff-super-bg: rgba(244, 63, 94, 0.13);

  /* Texto e Tipografia */
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --font-ui: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Teclado Numérico Tátil 3D */
  --key-bg: linear-gradient(180deg, rgba(32, 40, 64, 0.92) 0%, rgba(20, 26, 42, 0.95) 100%);
  --key-hover: linear-gradient(180deg, rgba(44, 55, 86, 0.98) 0%, rgba(28, 36, 58, 0.98) 100%);
  --key-active: rgba(0, 245, 212, 0.22);
  --key-border: rgba(255, 255, 255, 0.11);
  --key-shadow: 0 4px 0 rgba(6, 8, 15, 0.85), 0 8px 16px rgba(0, 0, 0, 0.4);
  --key-text: #f8fafc;

  /* Elevação, Sombras e Raios */
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --radius-xl: 28px;
  --radius-full: 9999px;
  --shadow-card: 0 20px 45px -15px rgba(0, 0, 0, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  --shadow-glow: 0 0 28px -4px var(--cyan-glow);

  /* Transições */
  --transition-fast: 130ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 240ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-bounce: 360ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ==========================================================================
   Temas Alternativos: AMOLED & Clean Light
   ========================================================================== */

[data-theme="amoled"] {
  --bg-dark: #000000;
  --bg-surface: #050508;
  --bg-card: rgba(10, 11, 16, 0.92);
  --bg-card-solid: #08090d;
  --bg-card-hover: rgba(18, 20, 30, 0.96);
  --bg-elevated: rgba(18, 20, 28, 0.9);
  --key-bg: linear-gradient(180deg, #12141d 0%, #0a0b10 100%);
  --key-hover: linear-gradient(180deg, #1b1f2e 0%, #11131c 100%);
  --border-subtle: rgba(255, 255, 255, 0.13);
  --key-shadow: 0 4px 0 #000000, 0 6px 14px rgba(0, 0, 0, 0.8);
}

[data-theme="light"] {
  --bg-dark: #eef2f8;
  --bg-surface: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.88);
  --bg-card-solid: #ffffff;
  --bg-card-hover: #ffffff;
  --bg-elevated: rgba(241, 245, 249, 0.95);
  --bg-glass: rgba(15, 23, 42, 0.04);
  --border-subtle: rgba(15, 23, 42, 0.1);
  --border-highlight: rgba(15, 23, 42, 0.18);
  --border-glow: rgba(0, 150, 136, 0.35);

  --cyan-primary: #009688;
  --cyan-secondary: #0284c7;
  --cyan-glow: rgba(0, 150, 136, 0.25);
  --amber-gold: #d97706;
  --amber-glow: rgba(217, 119, 6, 0.25);
  --diff-medium: #009688;
  --diff-medium-bg: rgba(0, 150, 136, 0.1);

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;

  --key-bg: linear-gradient(180deg, #ffffff 0%, #f1f5f9 100%);
  --key-hover: linear-gradient(180deg, #ffffff 0%, #e2e8f0 100%);
  --key-active: rgba(0, 150, 136, 0.16);
  --key-border: rgba(15, 23, 42, 0.14);
  --key-shadow: 0 4px 0 #cbd5e1, 0 6px 14px rgba(15, 23, 42, 0.08);
  --key-text: #0f172a;
  --shadow-card: 0 18px 40px -15px rgba(15, 23, 42, 0.12), inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

/* ==========================================================================
   Reset, Base & Camada Atmosférica
   ========================================================================== */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-ui);
  height: 100%;
  width: 100%;
  overflow: hidden;
  touch-action: manipulation;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  min-height: 100dvh;
  height: 100dvh;
  max-height: 100dvh;
  width: 100vw;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background-color: var(--bg-dark);
  color: var(--text-main);
  user-select: none;
  -webkit-user-select: none;
  position: fixed;
  inset: 0;
  padding-top: env(safe-area-inset-top, 0px);
  padding-bottom: env(safe-area-inset-bottom, 0px);
  padding-left: env(safe-area-inset-left, 0px);
  padding-right: env(safe-area-inset-right, 0px);
}

/* Camada Atmosférica Quântica (Orbs + Grid Sutil) */
.ambient-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.45;
  animation: floatOrb 18s ease-in-out infinite alternate;
}

[data-theme="amoled"] .ambient-orb {
  opacity: 0.2;
}

[data-theme="light"] .ambient-orb {
  opacity: 0.25;
}

.orb-cyan {
  width: 42vw;
  height: 42vw;
  min-width: 260px;
  min-height: 260px;
  background: radial-gradient(circle, rgba(0, 245, 212, 0.28) 0%, transparent 70%);
  top: -12%;
  right: -8%;
}

.orb-purple {
  width: 48vw;
  height: 48vw;
  min-width: 300px;
  min-height: 300px;
  background: radial-gradient(circle, rgba(121, 40, 202, 0.3) 0%, transparent 70%);
  bottom: -15%;
  left: -10%;
  animation-delay: -6s;
}

.orb-pink {
  width: 32vw;
  height: 32vw;
  min-width: 200px;
  min-height: 200px;
  background: radial-gradient(circle, rgba(255, 0, 122, 0.16) 0%, transparent 70%);
  top: 35%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -11s;
}

@keyframes floatOrb {
  0% { transform: translate(0, 0) scale(1); }
  100% { transform: translate(-20px, 25px) scale(1.08); }
}

.quantum-grid-overlay {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.022) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.022) 1px, transparent 1px);
  background-size: 36px 36px;
  mask-image: radial-gradient(circle at 50% 50%, black 35%, transparent 90%);
  -webkit-mask-image: radial-gradient(circle at 50% 50%, black 35%, transparent 90%);
}

[data-theme="light"] .quantum-grid-overlay {
  background-image: 
    linear-gradient(to right, rgba(15, 23, 42, 0.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(15, 23, 42, 0.035) 1px, transparent 1px);
}

/* Container de Partículas de Vitória */
.fx-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1500;
  overflow: hidden;
}

.fx-particle {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  pointer-events: none;
  animation: particleFall 1.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes particleFall {
  0% {
    opacity: 1;
    transform: translate(0, 0) rotate(0deg) scale(1);
  }
  100% {
    opacity: 0;
    transform: translate(var(--tx), var(--ty)) rotate(var(--rot)) scale(0.3);
  }
}

/* ==========================================================================
   Container Principal Responsivo (Mobile -> Tablet -> Desktop)
   ========================================================================== */

.app-container {
  display: flex;
  flex-direction: column;
  height: 100%;
  width: 100%;
  max-width: 540px;
  margin: 0 auto;
  padding: 10px 16px;
  position: relative;
  z-index: 1;
  justify-content: space-between;
  overflow: hidden;
  transition: max-width var(--transition-normal), padding var(--transition-normal);
}

/* ==========================================================================
   Header & Navegação Superior
   ========================================================================== */

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  cursor: pointer;
  outline: none;
  border-radius: var(--radius-sm);
  padding: 2px 4px 2px 0;
  transition: transform var(--transition-fast);
}

.brand:hover {
  transform: translateY(-1px);
}

.brand:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan-primary);
}

.brand-icon-wrap {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: rgba(0, 245, 212, 0.08);
  border: 1px solid rgba(0, 245, 212, 0.22);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.brand-icon {
  width: 28px;
  height: 28px;
  filter: drop-shadow(0 0 8px var(--cyan-glow));
  animation: pulseBrand 4s ease-in-out infinite;
}

@keyframes pulseBrand {
  0%, 100% { transform: scale(1); filter: drop-shadow(0 0 5px var(--cyan-glow)); }
  50% { transform: scale(1.06); filter: drop-shadow(0 0 11px var(--pink-glow)); }
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.05;
}

.brand-title {
  font-size: 1.35rem;
  font-weight: 900;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--cyan-primary) 0%, #a855f7 55%, var(--pink-neon) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: flex;
  align-items: center;
  gap: 6px;
}

.brand-badge {
  font-size: 0.58rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  background: rgba(0, 245, 212, 0.14);
  border: 1px solid rgba(0, 245, 212, 0.38);
  color: var(--cyan-primary);
  padding: 2px 6px;
  border-radius: var(--radius-full);
  -webkit-text-fill-color: var(--cyan-primary);
}

.brand-tagline {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 0.03em;
  display: none;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.icon-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.icon-btn:hover {
  background: var(--bg-card-hover);
  color: var(--cyan-primary);
  border-color: var(--border-glow);
  transform: translateY(-1px);
}

.icon-btn:active {
  transform: scale(0.92);
}

.icon-btn svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

/* Indicador de Streak no Header */
.streak-chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: rgba(255, 183, 3, 0.12);
  border: 1px solid rgba(255, 183, 3, 0.35);
  color: var(--amber-gold);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  font-size: 0.82rem;
  height: 36px;
  padding: 0 10px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.streak-chip:hover {
  background: rgba(255, 183, 3, 0.2);
  transform: translateY(-1px);
}

.streak-chip svg {
  width: 15px;
  height: 15px;
  fill: var(--amber-gold);
  filter: drop-shadow(0 0 4px var(--amber-glow));
}

.streak-label {
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 700;
  opacity: 0.85;
  display: none;
}

/* ==========================================================================
   MENU INICIAL (Card Hub Central)
   ========================================================================== */

.start-screen {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  flex: 1 1 auto;
  width: 100%;
  padding: 6px 0;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: none;
}

.start-screen::-webkit-scrollbar {
  display: none;
}

.menu-hub-card {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 16px 15px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  position: relative;
}

.hub-col-main {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Seletor de Modos */
.mode-selector {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
  background: rgba(6, 8, 15, 0.65);
  padding: 4px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

[data-theme="light"] .mode-selector {
  background: rgba(15, 23, 42, 0.06);
}

.mode-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  font-family: var(--font-ui);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 8px 6px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.mode-btn:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.04);
}

.mode-btn.active {
  background: linear-gradient(135deg, rgba(0, 245, 212, 0.2) 0%, rgba(121, 40, 202, 0.25) 100%);
  color: var(--cyan-primary);
  border-color: rgba(0, 245, 212, 0.42);
  box-shadow: 0 4px 12px -2px var(--cyan-glow);
}

.mode-btn svg {
  width: 15px;
  height: 15px;
  fill: currentColor;
  flex-shrink: 0;
}

/* Cabeçalho do Hub */
.hub-header {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.hub-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: rgba(0, 245, 212, 0.11);
  border: 1px solid rgba(0, 245, 212, 0.32);
  color: var(--cyan-primary);
  font-size: 0.7rem;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.hub-badge.completed {
  background: rgba(16, 185, 129, 0.14);
  border-color: rgba(16, 185, 129, 0.45);
  color: var(--emerald-success);
}

.hub-title {
  font-size: clamp(1.25rem, 4vw, 1.55rem);
  font-weight: 900;
  color: var(--text-main);
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.hub-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.35;
  max-width: 44ch;
}

/* Resumo Rápido de Métricas no Hub */
.hub-quick-metrics {
  display: flex;
  align-items: center;
  justify-content: space-around;
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 8px 10px;
}

.quick-metric {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1px;
}

.qm-label {
  font-size: 0.64rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
}

.qm-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--cyan-primary);
}

.quick-metric-divider {
  width: 1px;
  height: 24px;
  background: var(--border-subtle);
}

/* Seletor de Dificuldade */
.difficulty-section {
  display: flex;
  flex-direction: column;
  gap: 7px;
}

.section-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-label {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 5px;
}

.desktop-shortcut-tip {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-dim);
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  padding: 1px 7px;
  border-radius: var(--radius-xs);
}

.difficulty-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 7px;
}

.diff-card {
  background: var(--bg-elevated);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 9px 11px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 4px;
  text-align: left;
  transition: all var(--transition-fast);
  position: relative;
  font-family: var(--font-ui);
  color: inherit;
  outline: none;
  overflow: hidden;
}

.diff-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-highlight);
  transform: translateY(-1px);
}

/* Cores Dinâmicas por Dificuldade quando Ativo */
.diff-card[data-diff="facil"] { --card-accent: var(--diff-easy); --card-bg: var(--diff-easy-bg); }
.diff-card[data-diff="medio"] { --card-accent: var(--diff-medium); --card-bg: var(--diff-medium-bg); }
.diff-card[data-diff="dificil"] { --card-accent: var(--diff-hard); --card-bg: var(--diff-hard-bg); }
.diff-card[data-diff="super"] { --card-accent: var(--diff-super); --card-bg: var(--diff-super-bg); }

.diff-card.active {
  border-color: var(--card-accent);
  background: var(--card-bg);
  box-shadow: 0 6px 20px -6px var(--card-accent);
}

.diff-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4px;
}

.diff-name {
  font-weight: 800;
  font-size: 0.86rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 6px;
}

.diff-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--card-accent);
  box-shadow: 0 0 8px var(--card-accent);
  flex-shrink: 0;
}

.diff-meta {
  display: flex;
  align-items: center;
  gap: 5px;
}

.diff-status-badge {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  color: var(--emerald-success);
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  padding: 1px 5px;
  border-radius: var(--radius-full);
  display: none;
}

.diff-status-badge.done {
  display: inline-flex;
  align-items: center;
}

.diff-key {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 700;
  color: var(--text-dim);
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--border-subtle);
  padding: 1px 5px;
  border-radius: 4px;
}

.diff-check {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1.5px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.diff-card.active .diff-check {
  border-color: var(--card-accent);
  background: var(--card-accent);
}

.diff-card.active .diff-check::after {
  content: "✓";
  color: #040810;
  font-size: 10px;
  font-weight: 900;
}

.diff-desc {
  font-size: 0.68rem;
  color: var(--text-muted);
  line-height: 1.25;
}

.diff-ops-preview {
  display: none;
  align-items: center;
  gap: 4px;
  margin-top: 2px;
}

.diff-ops-preview span {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  color: var(--text-dim);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  padding: 1px 5px;
  border-radius: 4px;
}

.diff-card.active .diff-ops-preview span {
  color: var(--text-main);
  border-color: rgba(255, 255, 255, 0.16);
}

/* Botão Central de Jogar (Ordenação no Mobile vs Desktop) */
.hub-action-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

/* No Mobile/Tablet Portrait, queremos o botão Jogar abaixo da escolha de dificuldade */
@media (max-width: 959px) {
  .menu-hub-card {
    display: flex;
    flex-direction: column;
  }
  .hub-col-main {
    display: contents;
  }
  .mode-selector { order: 1; }
  .hub-header { order: 2; }
  .hub-quick-metrics { order: 3; }
  .difficulty-section { order: 4; }
  .hub-action-box { order: 5; margin-top: 2px; }
}

.btn-play-hero {
  width: 100%;
  height: 50px;
  background: linear-gradient(135deg, #00f5d4 0%, #00bbf9 50%, #7928ca 100%);
  color: #040810;
  border: none;
  font-family: var(--font-ui);
  font-size: 1.08rem;
  font-weight: 900;
  letter-spacing: 0.03em;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 8px 24px -4px var(--cyan-glow), inset 0 1px 0 rgba(255, 255, 255, 0.45);
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn-play-hero:hover {
  filter: brightness(1.08);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -2px var(--cyan-glow), inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

.btn-play-hero:active {
  transform: scale(0.98);
}

.btn-play-hero svg {
  width: 22px;
  height: 22px;
  fill: currentColor;
  flex-shrink: 0;
}

.kbd-hint {
  display: none;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 800;
  background: rgba(4, 8, 16, 0.22);
  color: #040810;
  padding: 2px 7px;
  border-radius: 6px;
  border: 1px solid rgba(4, 8, 16, 0.25);
  margin-left: 4px;
}

.rule-hint {
  font-size: 0.72rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  font-weight: 600;
  text-align: center;
}

/* ==========================================================================
   TELA DE JOGO / GAMEPLAY SCREEN
   ========================================================================== */

.gameplay-screen {
  display: none;
  flex-direction: column;
  height: 100%;
  width: 100%;
  justify-content: space-between;
  gap: 8px;
  padding: 4px 0;
  overflow: hidden;
}

.match-status-bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.status-left {
  display: flex;
  align-items: center;
  gap: 6px;
  justify-self: start;
}

.status-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.status-right {
  display: flex;
  align-items: center;
  gap: 6px;
  justify-self: end;
}

.btn-back-menu {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 700;
  height: 34px;
  padding: 0 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
  transition: all var(--transition-fast);
}

.btn-back-menu:hover {
  background: var(--bg-card-hover);
  color: var(--text-main);
  border-color: var(--border-glow);
}

.btn-back-menu svg {
  width: 14px;
  height: 14px;
  fill: currentColor;
}

.active-diff-pill {
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 8px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  display: none;
}

.active-diff-pill[data-diff="facil"] { color: var(--diff-easy); border-color: rgba(16, 185, 129, 0.35); background: var(--diff-easy-bg); }
.active-diff-pill[data-diff="medio"] { color: var(--diff-medium); border-color: rgba(0, 245, 212, 0.35); background: var(--diff-medium-bg); }
.active-diff-pill[data-diff="dificil"] { color: var(--diff-hard); border-color: rgba(249, 115, 22, 0.35); background: var(--diff-hard-bg); }
.active-diff-pill[data-diff="super"] { color: var(--diff-super); border-color: rgba(244, 63, 94, 0.35); background: var(--diff-super-bg); }

/* Timer Monospaçado Tabular (Zero Jitter) */
.timer-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text-main);
  background: var(--bg-card);
  height: 34px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06);
}

.timer-pill svg {
  width: 15px;
  height: 15px;
  fill: var(--cyan-primary);
  flex-shrink: 0;
}

.timer-pill.urgent {
  color: var(--rose-danger);
  border-color: var(--rose-danger);
  animation: pulseUrgent 0.55s infinite alternate;
}

.timer-pill.urgent svg {
  fill: var(--rose-danger);
}

@keyframes pulseUrgent {
  from { box-shadow: 0 0 4px transparent; }
  to { box-shadow: 0 0 14px var(--rose-glow); }
}

.score-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--text-muted);
  background: var(--bg-card);
  height: 34px;
  padding: 0 11px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.score-pill span.highlight {
  color: var(--cyan-primary);
  font-weight: 800;
}

/* Barra de Progresso do Modo Blitz */
.blitz-progress-wrap {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  flex-shrink: 0;
}

.blitz-progress-bar {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--cyan-primary), var(--purple-accent));
  border-radius: var(--radius-full);
  transition: width 80ms linear, background-color 300ms ease;
}

.blitz-progress-bar.urgent {
  background: linear-gradient(90deg, var(--amber-gold), var(--rose-danger));
}

/* Barra de Pips do Desafio Diário (10 equações) */
.progress-pips {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  flex-shrink: 0;
}

.pip {
  flex: 1;
  height: 7px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.12);
  transition: all var(--transition-normal);
  position: relative;
}

[data-theme="light"] .pip {
  background: rgba(15, 23, 42, 0.14);
}

.pip.completed {
  background: var(--emerald-success);
  box-shadow: 0 0 8px var(--emerald-glow);
}

.pip.completed-retry {
  background: var(--amber-gold);
  box-shadow: 0 0 8px var(--amber-glow);
}

.pip.current {
  background: var(--cyan-primary);
  box-shadow: 0 0 12px var(--cyan-glow);
  transform: scaleY(1.35);
}

/* ==========================================================================
   Workspace do Jogo (Arena + Teclado)
   ========================================================================== */

.gameplay-workspace {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  flex: 1 1 auto;
  gap: 10px;
  width: 100%;
  min-height: 0;
}

.game-arena {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  position: relative;
  width: 100%;
  gap: 8px;
  min-height: 0;
}

.equation-card {
  width: 100%;
  background: var(--bg-card);
  border: 1.5px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: var(--shadow-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
}

.equation-card-top {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
  min-height: 22px;
}

.question-counter-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  padding: 2px 9px;
  border-radius: var(--radius-full);
}

.combo-badge {
  background: linear-gradient(135deg, var(--amber-gold), var(--pink-neon));
  color: #040810;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.72rem;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px var(--amber-glow);
  letter-spacing: 0.04em;
  transform: scale(0);
  opacity: 0;
  transition: transform var(--transition-bounce), opacity var(--transition-fast);
}

.combo-badge.visible {
  transform: scale(1);
  opacity: 1;
}

.equation-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.25rem, 7.5vw, 3.6rem);
  font-weight: 800;
  line-height: 1.1;
  color: var(--text-main);
  letter-spacing: -0.02em;
  margin: 4px 0;
}

.equation-row.pop-anim {
  animation: equationPop 180ms cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes equationPop {
  0% { opacity: 0.3; transform: translateY(6px) scale(0.97); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}

.operand {
  color: var(--text-main);
}

.operator {
  color: var(--cyan-primary);
  font-weight: 900;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 245, 212, 0.1);
  border: 1px solid rgba(0, 245, 212, 0.25);
  border-radius: var(--radius-sm);
  padding: 2px 12px;
  font-size: 0.78em;
  text-shadow: 0 0 14px var(--cyan-glow);
}

.equals-sign {
  color: var(--text-dim);
  font-weight: 500;
}

/* Área de Resposta do Jogador */
.answer-box {
  margin-top: 12px;
  min-width: 180px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(6, 8, 15, 0.78);
  border: 2px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.95rem, 5.8vw, 2.6rem);
  font-weight: 800;
  color: var(--cyan-primary);
  position: relative;
  padding: 0 20px;
  letter-spacing: 0.04em;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.55);
  transition: all var(--transition-fast);
}

[data-theme="light"] .answer-box {
  background: #f8fafc;
  box-shadow: inset 0 2px 5px rgba(15, 23, 42, 0.07);
}

.answer-box.focused {
  border-color: var(--cyan-primary);
  box-shadow: 0 0 22px -3px var(--cyan-glow), inset 0 2px 8px rgba(0, 0, 0, 0.5);
}

#answerValue {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.answer-placeholder {
  color: var(--text-dim);
  font-size: 1.75rem;
  opacity: 0.4;
}

.caret-cursor {
  display: inline-block;
  width: 3px;
  height: 30px;
  background-color: var(--cyan-primary);
  margin-left: 4px;
  border-radius: 2px;
  animation: blinkCursor 0.9s infinite;
  box-shadow: 0 0 8px var(--cyan-glow);
}

@keyframes blinkCursor {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.arena-micro-status {
  margin-top: 8px;
  font-size: 0.68rem;
  color: var(--text-dim);
  font-weight: 600;
  display: none;
}

/* Feedback de Acerto e Erro */
.equation-card.correct-flash {
  border-color: var(--emerald-success);
  box-shadow: 0 0 35px var(--emerald-glow);
  animation: correctPulse 0.26s ease-out;
}

.equation-card.wrong-shake {
  border-color: var(--rose-danger);
  box-shadow: 0 0 35px var(--rose-glow);
  animation: wrongShake 0.36s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

@keyframes correctPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.025); }
  100% { transform: scale(1); }
}

@keyframes wrongShake {
  10%, 90% { transform: translate3d(-4px, 0, 0); }
  20%, 80% { transform: translate3d(6px, 0, 0); }
  30%, 50%, 70% { transform: translate3d(-7px, 0, 0); }
  40%, 60% { transform: translate3d(7px, 0, 0); }
}

/* Barra de Telemetria em Tempo Real */
.live-telemetry-bar {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  width: 100%;
}

.telemetry-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
}

.tel-label {
  font-size: 0.66rem;
  font-weight: 700;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.tel-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.82rem;
  font-weight: 800;
  color: var(--text-main);
}

/* Opções de Filtro do Modo Treino */
.practice-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px;
  width: 100%;
}

.practice-filter-label {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-dim);
  margin-right: 2px;
}

.filter-chip {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-family: var(--font-ui);
  font-size: 0.76rem;
  font-weight: 700;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-chip:hover {
  color: var(--text-main);
  border-color: var(--border-highlight);
}

.filter-chip.active {
  background: rgba(0, 245, 212, 0.16);
  border-color: var(--cyan-primary);
  color: var(--cyan-primary);
  box-shadow: 0 0 12px -2px var(--cyan-glow);
}

/* ==========================================================================
   Teclado Virtual Tátil 3D (Numeric Keypad 3x4)
   ========================================================================== */

.keypad-panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
  flex-shrink: 0;
}

.keypad-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
  width: 100%;
}

.key-btn {
  background: var(--key-bg);
  border: 1px solid var(--key-border);
  color: var(--key-text);
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 4.2vw, 1.75rem);
  font-weight: 800;
  height: clamp(48px, 7vh, 62px);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: transform 55ms ease, background 120ms ease, border-color 120ms ease, box-shadow 55ms ease;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
  box-shadow: var(--key-shadow), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  position: relative;
}

.key-btn:hover {
  background: var(--key-hover);
  border-color: var(--border-highlight);
}

.key-btn:active, .key-btn.is-pressed {
  transform: translateY(3px) scale(0.97);
  background: var(--key-active);
  border-color: var(--cyan-primary);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.8), 0 0 16px var(--cyan-glow);
  color: var(--cyan-primary);
}

.key-btn.action-clear {
  color: var(--rose-danger);
  font-size: 1.15rem;
  font-family: var(--font-ui);
  font-weight: 900;
}

.key-btn.action-clear:active, .key-btn.action-clear.is-pressed {
  border-color: var(--rose-danger);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.8), 0 0 16px var(--rose-glow);
}

.key-btn.action-backspace {
  color: var(--amber-gold);
}

.key-btn.action-backspace:active, .key-btn.action-backspace.is-pressed {
  border-color: var(--amber-gold);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.8), 0 0 16px var(--amber-glow);
}

.key-btn.action-backspace svg {
  width: 23px;
  height: 23px;
  fill: currentColor;
}

.desktop-keyboard-legend {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 12px;
  font-size: 0.72rem;
  color: var(--text-dim);
  padding-top: 2px;
}

.desktop-keyboard-legend kbd {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 1px 6px;
  border-radius: 4px;
  margin-right: 3px;
}

/* ==========================================================================
   Footer Institucional & Instalação PWA
   ========================================================================== */

.app-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 6px;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.74rem;
  color: var(--text-dim);
  flex-shrink: 0;
}

.footer-links {
  display: flex;
  gap: 14px;
}

.footer-link {
  color: var(--text-dim);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--cyan-primary);
}

.footer-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.footer-shortcut-hint {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-dim);
  opacity: 0.75;
}

.install-btn {
  background: rgba(0, 245, 212, 0.12);
  border: 1px solid rgba(0, 245, 212, 0.35);
  color: var(--cyan-primary);
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: none;
  align-items: center;
  gap: 5px;
  transition: all var(--transition-fast);
}

.install-btn:hover {
  background: rgba(0, 245, 212, 0.22);
  transform: translateY(-1px);
}

/* ==========================================================================
   Modais (Estatísticas, Como Jogar, Configurações e Resultado)
   ========================================================================== */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(4, 6, 12, 0.78);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-dialog {
  background: var(--bg-surface);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 460px;
  max-height: 90dvh;
  overflow-y: auto;
  box-shadow: var(--shadow-card), 0 0 50px rgba(0, 0, 0, 0.75);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transform: scale(0.94) translateY(10px);
  transition: transform var(--transition-bounce);
}

.modal-overlay.active .modal-dialog {
  transform: scale(1) translateY(0);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

.modal-close-btn {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  width: 34px;
  height: 34px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.modal-close-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-main);
  border-color: var(--border-highlight);
}

.modal-close-btn svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.modal-body {
  display: flex;
  flex-direction: column;
  gap: 14px;
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--text-muted);
}

.howto-list {
  padding-left: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  text-align: center;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  padding: 10px 6px;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
}

.stat-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--cyan-primary);
}

.stat-label {
  font-size: 0.63rem;
  color: var(--text-dim);
  text-transform: uppercase;
  font-weight: 800;
  letter-spacing: 0.04em;
}

/* Subbox de Recordes por Dificuldade */
.stats-subbox {
  background: var(--bg-glass);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stats-subbox-title {
  font-size: 0.72rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

.diff-records-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.diff-rec-pill {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
}

.dr-name {
  font-weight: 700;
  color: var(--text-main);
}

.dr-val {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  color: var(--cyan-primary);
}

.modal-result-dialog {
  max-width: 480px;
}

.share-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.share-format-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.share-format-label {
  font-size: 0.74rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
}

.share-badge-story {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--cyan-primary);
  background: rgba(0, 245, 212, 0.12);
  border: 1px solid rgba(0, 245, 212, 0.35);
  padding: 3px 8px;
  border-radius: var(--radius-full);
}

.share-canvas-preview-wrap {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(4, 6, 12, 0.55);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 8px;
  overflow: hidden;
}

#shareCanvas {
  max-width: 100%;
  max-height: 280px;
  width: auto;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.65);
  display: block;
  transition: all var(--transition-normal);
}

.share-actions-grid {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.btn-share-main {
  width: 100%;
}

.share-secondary-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.btn-sm-action {
  padding: 9px 12px;
  font-size: 0.82rem;
}

.countdown-footer {
  text-align: center;
  font-size: 0.84rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.countdown-digits {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 800;
  color: var(--cyan-primary);
}

.btn-primary {
  background: linear-gradient(135deg, var(--cyan-primary) 0%, var(--cyan-secondary) 100%);
  color: #040810;
  border: none;
  font-family: var(--font-ui);
  font-weight: 800;
  font-size: 0.95rem;
  padding: 12px 20px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  box-shadow: 0 4px 16px var(--cyan-glow);
  transition: all var(--transition-fast);
}

.btn-primary:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
  box-shadow: 0 6px 22px var(--cyan-glow);
}

.btn-primary:active {
  transform: scale(0.97);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
  font-family: var(--font-ui);
  font-weight: 700;
  font-size: 0.9rem;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
}

.btn-danger-outline {
  width: 100%;
  color: var(--rose-danger);
  border-color: rgba(244, 63, 94, 0.32);
}

.btn-danger-outline:hover {
  background: rgba(244, 63, 94, 0.12);
  border-color: var(--rose-danger);
}

/* Configurações: Toggles & Selects */
.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-subtle);
}

.blitz-record-row {
  border-bottom: none;
  padding-bottom: 2px;
}

.setting-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.setting-title {
  color: var(--text-main);
  font-weight: 700;
  font-size: 0.92rem;
}

.setting-desc {
  font-size: 0.76rem;
  color: var(--text-dim);
}

.ui-select {
  background: var(--bg-card-solid);
  color: var(--text-main);
  border: 1px solid var(--border-highlight);
  font-family: var(--font-ui);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  outline: none;
}

.ui-select:focus {
  border-color: var(--cyan-primary);
}

.switch {
  position: relative;
  display: inline-block;
  width: 46px;
  height: 26px;
  flex-shrink: 0;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background-color: var(--bg-card);
  border: 1px solid var(--border-highlight);
  transition: var(--transition-fast);
  border-radius: var(--radius-full);
}

.slider:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: var(--text-muted);
  transition: var(--transition-fast);
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--cyan-primary);
  border-color: var(--cyan-primary);
}

input:checked + .slider:before {
  transform: translateX(20px);
  background-color: #06080f;
}

/* Toast Notifications */
.toast-container {
  position: fixed;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  background: var(--bg-card-solid);
  border: 1px solid var(--cyan-primary);
  color: var(--text-main);
  padding: 10px 18px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.55), 0 0 16px var(--cyan-glow);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: toastIn 0.28s cubic-bezier(0.16, 1, 0.3, 1), toastOut 0.28s cubic-bezier(0.16, 1, 0.3, 1) 2.5s forwards;
}

@keyframes toastIn {
  from { opacity: 0; transform: translateY(-16px) scale(0.92); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes toastOut {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to { opacity: 0; transform: translateY(-12px) scale(0.92); }
}

/* ==========================================================================
   PÁGINAS INSTITUCIONAIS (como-jogar, privacidade, termos)
   ========================================================================== */

.content-page {
  height: auto;
  min-height: 100%;
  overflow-y: auto;
  position: static;
  display: block;
}

.content-page .app-container {
  max-width: 820px;
  height: auto;
  min-height: 100vh;
  padding: 28px 20px 56px 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  overflow: visible;
}

.content-article {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-card);
  color: var(--text-muted);
  line-height: 1.75;
}

.content-article h1 {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.content-article .lead {
  font-size: 1.05rem;
  color: var(--cyan-primary);
  margin-bottom: 24px;
  font-weight: 600;
}

.content-article h2 {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-main);
  margin-top: 28px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 6px;
}

.content-article h3 {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 18px;
  margin-bottom: 8px;
}

.content-article p {
  margin-bottom: 16px;
}

.content-article ul, .content-article ol {
  margin-left: 20px;
  margin-bottom: 18px;
}

.content-article li {
  margin-bottom: 8px;
}

.content-article code {
  background: rgba(0, 245, 212, 0.1);
  color: var(--cyan-primary);
  padding: 2px 6px;
  border-radius: var(--radius-xs);
  font-family: var(--font-mono);
  font-size: 0.88em;
}

.back-to-game-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--cyan-primary);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.92rem;
  transition: transform var(--transition-fast);
  width: fit-content;
}

.back-to-game-btn:hover {
  transform: translateX(-4px);
}

/* ==========================================================================
   RESPONSIVIDADE MULTI-DISPOSITIVO:
   1) Telas Compactas / Celulares Pequenos (max-height: 690px)
   2) Celulares em Modo Paisagem (Landscape Mobile)
   3) Tablets (768px - 959px)
   4) Monitores Desktop, Notebooks & Tablets Landscape (min-width: 960px)
   ========================================================================== */

/* 1. Celulares Compactos (ex: iPhone SE / janelas baixas) */
@media (max-width: 767px) and (max-height: 690px) {
  .app-container {
    padding: 6px 12px;
  }
  .app-header {
    padding-bottom: 4px;
  }
  .menu-hub-card {
    padding: 11px 12px;
    gap: 8px;
  }
  .hub-title {
    font-size: 1.15rem;
  }
  .hub-subtitle {
    font-size: 0.72rem;
  }
  .hub-quick-metrics {
    padding: 5px 8px;
  }
  .diff-card {
    padding: 6px 8px;
  }
  .diff-desc {
    font-size: 0.63rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
  }
  .btn-play-hero {
    height: 42px;
    font-size: 0.98rem;
  }
  .equation-card {
    padding: 12px;
  }
  .answer-box {
    height: 46px;
    margin-top: 8px;
  }
  .live-telemetry-bar {
    display: none;
  }
  .key-btn {
    height: 43px;
    font-size: 1.25rem;
  }
}

/* 2. Dispositivos Móveis em Modo Paisagem (Landscape Mobile/Phablet) */
@media (max-height: 540px) and (orientation: landscape) {
  .app-container {
    max-width: 920px;
    padding: 6px 16px;
  }
  .app-footer {
    display: none;
  }
  .menu-hub-card {
    display: grid;
    grid-template-columns: 1fr 1.15fr;
    gap: 14px;
    padding: 12px 16px;
    align-items: center;
  }
  .hub-col-main {
    display: flex;
    flex-direction: column;
    gap: 8px;
  }
  .hub-quick-metrics {
    display: none;
  }
  .btn-play-hero {
    height: 40px;
    font-size: 0.95rem;
  }
  .gameplay-workspace {
    flex-direction: row;
    align-items: stretch;
    gap: 14px;
  }
  .game-arena {
    flex: 1.15;
  }
  .equation-card {
    height: 100%;
    padding: 10px 14px;
  }
  .equation-row {
    font-size: 2.1rem;
  }
  .answer-box {
    height: 44px;
    margin-top: 8px;
  }
  .live-telemetry-bar {
    display: none;
  }
  .keypad-panel {
    flex: 0.95;
    justify-content: center;
  }
  .key-btn {
    height: 38px;
    font-size: 1.15rem;
  }
}

/* 3. Tablets em Modo Retrato (768px a 959px) */
@media (min-width: 768px) and (max-width: 959px) and (min-height: 541px) {
  .app-container {
    max-width: 680px;
    padding: 18px 28px;
  }
  .brand-tagline,
  .streak-label,
  .active-diff-pill,
  .diff-ops-preview,
  .arena-micro-status {
    display: inline-flex;
  }
  .menu-hub-card {
    padding: 24px;
    gap: 16px;
  }
  .diff-card {
    padding: 12px 14px;
    gap: 6px;
  }
  .diff-name {
    font-size: 0.95rem;
  }
  .diff-desc {
    font-size: 0.76rem;
  }
  .btn-play-hero {
    height: 56px;
    font-size: 1.18rem;
  }
  .equation-card {
    padding: 28px 24px;
  }
  .answer-box {
    height: 64px;
    min-width: 220px;
  }
  .key-btn {
    height: 60px;
    font-size: 1.65rem;
  }
}

/* 4. Monitores de Computador, Notebooks & Tablets Landscape (>= 960px) */
@media (min-width: 960px) and (min-height: 541px) {
  .app-container {
    max-width: 1040px;
    padding: 20px 36px;
  }

  .brand-tagline,
  .streak-label,
  .active-diff-pill,
  .desktop-shortcut-tip,
  .diff-key,
  .diff-ops-preview,
  .kbd-hint,
  .arena-micro-status,
  .desktop-keyboard-legend {
    display: inline-flex;
  }

  .app-header {
    padding-bottom: 12px;
  }

  .icon-btn {
    width: 40px;
    height: 40px;
  }

  /* Menu Hub no Desktop: Bento Grid de 2 Colunas Equilibradas */
  .menu-hub-card {
    display: grid;
    grid-template-columns: 1.05fr 1.15fr;
    gap: 28px;
    padding: 32px;
    align-items: stretch;
    border-radius: var(--radius-xl);
  }

  .hub-col-main {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 18px;
    padding-right: 24px;
    border-right: 1px solid var(--border-subtle);
  }

  .hub-header {
    text-align: left;
    align-items: flex-start;
    gap: 8px;
  }

  .hub-title {
    font-size: 2rem;
  }

  .hub-subtitle {
    font-size: 0.92rem;
    line-height: 1.5;
  }

  .hub-quick-metrics {
    padding: 12px 16px;
  }

  .qm-value {
    font-size: 1.15rem;
  }

  .difficulty-section {
    justify-content: space-between;
    gap: 12px;
  }

  .difficulty-grid {
    gap: 12px;
    flex: 1;
  }

  .diff-card {
    padding: 14px 16px;
    gap: 6px;
    border-radius: var(--radius-md);
  }

  .diff-name {
    font-size: 0.98rem;
  }

  .diff-desc {
    font-size: 0.78rem;
    line-height: 1.38;
  }

  .btn-play-hero {
    height: 58px;
    font-size: 1.15rem;
  }

  /* Tela de Jogo no Desktop: Split Arena + Dock Tátil Lateral */
  .gameplay-screen {
    gap: 14px;
  }

  .timer-pill {
    font-size: 1.2rem;
    height: 40px;
    padding: 0 16px;
  }

  .score-pill,
  .btn-back-menu {
    height: 40px;
    padding: 0 14px;
    font-size: 0.9rem;
  }

  .gameplay-workspace {
    display: grid;
    grid-template-columns: 1.35fr 0.95fr;
    gap: 24px;
    align-items: stretch;
    padding: 6px 0;
  }

  .game-arena {
    justify-content: space-between;
    gap: 14px;
  }

  .equation-card {
    flex: 1;
    padding: 32px 28px;
    border-radius: var(--radius-xl);
  }

  .equation-row {
    font-size: clamp(3rem, 4.2vw, 4.2rem);
    gap: 16px;
    margin: 12px 0;
  }

  .answer-box {
    min-width: 240px;
    height: 68px;
    font-size: 2.6rem;
    margin-top: 16px;
  }

  .telemetry-item {
    padding: 10px 14px;
    border-radius: var(--radius-md);
  }

  .tel-label {
    font-size: 0.72rem;
  }

  .tel-value {
    font-size: 0.96rem;
  }

  .keypad-panel {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 22px;
    justify-content: space-between;
    box-shadow: var(--shadow-card);
    backdrop-filter: blur(20px);
  }

  .keypad-container {
    gap: 12px;
    flex: 1;
    align-content: stretch;
  }

  .key-btn {
    height: auto;
    min-height: 64px;
    font-size: 1.75rem;
    border-radius: var(--radius-md);
  }
}

/* 5. Monitores Grandes / Full HD & Ultrawide (>= 1280px e >= 760px de altura) */
@media (min-width: 1280px) and (min-height: 760px) {
  .app-container {
    max-width: 1120px;
    padding: 28px 40px;
  }
  .menu-hub-card {
    padding: 40px;
    gap: 36px;
  }
  .hub-title {
    font-size: 2.25rem;
  }
  .equation-row {
    font-size: 4.4rem;
  }
}