/* style.css
   Bright, colorful, modern styling for FlashEspañol.
   Mobile-first, single-column layout that scales up nicely on desktop. */

:root {
  /* "Spanish sun & tile" — warm saffron/terracotta over a deep ink base.
     Dominant warm tones with a single cool teal accent for contrast. */
  --color-bg-1: #f4a259;   /* saffron  */
  --color-bg-2: #e76f51;   /* terracotta */
  --color-bg-3: #7a2e3a;   /* deep sangria */
  --color-card-front: #fdf6ec; /* warm cream, not stark white */
  --color-card-back: #ffd670;  /* golden */
  --color-primary: #bc4749;    /* clay red */
  --color-accent: #2a9d8f;     /* teal — the one cool note */
  --color-known: #2a9d8f;
  --color-known-dark: #1e7d72;
  --color-learning: #ee6c4d;
  --color-learning-dark: #d1492b;
  --color-text: #3a2318;       /* warm espresso, not cold navy */
  --color-text-light: #9c7a63;
  --shadow: 0 12px 34px rgba(58, 35, 24, 0.32);
  --radius: 20px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  background:
    radial-gradient(circle at 18% 12%, rgba(255, 224, 138, 0.55), transparent 42%),
    radial-gradient(circle at 85% 78%, rgba(122, 46, 58, 0.55), transparent 50%),
    linear-gradient(160deg, var(--color-bg-1), var(--color-bg-2) 48%, var(--color-bg-3));
  background-attachment: fixed;
  color: var(--color-text);
  display: flex;
  justify-content: center;
  padding: 24px 16px 48px;
}

.app {
  width: 100%;
  max-width: 480px;
}

/* Header */
.app-header {
  text-align: center;
  color: #fff;
  margin-bottom: 20px;
}

.app-header h1 {
  margin: 0;
  font-size: 2rem;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.subtitle {
  margin: 4px 0 0;
  opacity: 0.95;
  font-weight: 500;
}

/* Progress */
.progress-section {
  background: rgba(255, 255, 255, 0.95);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin-bottom: 16px;
  box-shadow: var(--shadow);
}

.progress-stats {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 8px;
  text-align: center;
}

#known-count {
  color: var(--color-known-dark);
}

#learning-count {
  color: var(--color-learning-dark);
}

.progress-bar-track {
  width: 100%;
  height: 10px;
  background: #f0e0cf;
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-known), #57c9bb);
  border-radius: 999px;
  transition: width 0.3s ease;
}

/* Mode toggle */
.mode-toggle {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
}

.mode-btn {
  flex: 1;
  padding: 10px 8px;
  border: none;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.65);
  color: var(--color-text);
  font-weight: 600;
  font-size: 0.85rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

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

.mode-btn.active {
  background: #ffffff;
  color: var(--color-primary);
  box-shadow: var(--shadow);
}

/* Card area */
.card-area {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.card-counter {
  color: #fff;
  font-weight: 600;
  margin-bottom: 10px;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.2);
}

.card-scene {
  width: 100%;
  height: 260px;
  perspective: 1200px;
  margin-bottom: 20px;
}

.card {
  position: relative;
  width: 100%;
  height: 100%;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.5s ease;
}

.card.flipped {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  backface-visibility: hidden;
  box-shadow: var(--shadow);
  padding: 20px;
  text-align: center;
}

.card-front {
  background: var(--color-card-front);
}

.card-back {
  background: var(--color-card-back);
  transform: rotateY(180deg);
}

.card-label {
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-light);
}

.card-word {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-text);
  word-break: break-word;
}

.flip-hint {
  font-size: 0.8rem;
  color: var(--color-text-light);
  font-style: italic;
}

.empty-state {
  color: #fff;
  font-weight: 600;
  text-align: center;
  background: rgba(255, 255, 255, 0.15);
  border-radius: var(--radius);
  padding: 40px 20px;
  margin-bottom: 20px;
  width: 100%;
}

/* Grade buttons */
.grade-buttons {
  display: flex;
  gap: 12px;
  width: 100%;
  margin-bottom: 16px;
}

.grade-btn {
  flex: 1;
  padding: 14px 10px;
  border: none;
  border-radius: 14px;
  font-size: 0.95rem;
  font-weight: 700;
  color: #fff;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, filter 0.15s ease;
}

.grade-btn:hover {
  transform: translateY(-2px);
  filter: brightness(1.05);
}

.grade-btn:active {
  transform: translateY(0);
}

.learning-btn {
  background: linear-gradient(135deg, var(--color-learning), var(--color-learning-dark));
}

.known-btn {
  background: linear-gradient(135deg, var(--color-known), var(--color-known-dark));
}

/* Nav buttons */
.nav-buttons {
  display: flex;
  gap: 8px;
  width: 100%;
}

.nav-btn {
  flex: 1;
  padding: 10px 8px;
  border: none;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.85);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.85rem;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

.nav-btn:hover {
  background: #fff;
  transform: translateY(-1px);
}

/* Footer */
.app-footer {
  text-align: center;
  margin-top: 24px;
}

.reset-btn {
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.85);
  text-decoration: underline;
  font-size: 0.8rem;
  cursor: pointer;
}

.reset-btn:hover {
  color: #fff;
}

/* Small screens */
@media (max-width: 360px) {
  .card-word {
    font-size: 1.6rem;
  }
}