@import url("https://fonts.googleapis.com/css2?family=Outfit:wght@400;600;800&display=swap");

/* ─── Design tokens ─────────────────────────────────────────────────── */
:root {
  --bg-color: #0f172a;
  --surface-color: rgba(30, 41, 59, 0.7);
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --success-color: #10b981;
  --error-color: #ef4444;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: rgba(255, 255, 255, 0.1);
}

/* ─── Reset / base ──────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html {
  height: 100%;
}

body {
  margin: 0;
  font-family: "Outfit", system-ui, -apple-system, sans-serif;
  background: var(--bg-color);
  background-image: radial-gradient(circle at 50% 0%, #1e293b 0%, #0f172a 100%);
  color: var(--text-main);
  min-height: 100%;
  min-height: 100dvh;
  overflow-y: auto;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

/* ─── App shell ─────────────────────────────────────────────────────── */
#app {
  width: 100%;
  max-width: 600px;
  padding: 20px 16px 32px;
  text-align: center;
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
}

h1 {
  font-size: clamp(2rem, 8vw, 3rem);
  font-weight: 800;
  margin: 16px 0 20px;
  background: linear-gradient(to right, #60a5fa, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: 2px;
  flex-shrink: 0;
}

h2 {
  margin-top: 0;
  font-weight: 600;
  font-size: clamp(1rem, 4vw, 1.3rem);
}

/* ─── Glass panel ───────────────────────────────────────────────────── */
.glass-panel {
  background: var(--surface-color);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 24px 20px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  position: relative;
  /* No fixed max-height — let content determine height */
}

/* ─── Buttons ───────────────────────────────────────────────────────── */
button {
  padding: 12px 20px;
  margin: 6px;
  border-radius: 14px;
  border: none;
  font-weight: 600;
  font-size: 1rem;
  font-family: inherit;
  cursor: pointer;
  background: var(--primary-color);
  color: white;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  /* Mobile: minimum tap target */
  min-height: 48px;
  touch-action: manipulation;
}
button:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
}
button:active {
  transform: translateY(0);
}
button.secondary {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid var(--border-color);
  color: var(--text-main);
}
button.secondary:hover {
  background: rgba(255, 255, 255, 0.15);
}

/* ─── Input ─────────────────────────────────────────────────────────── */
input {
  padding: 14px 16px;
  font-size: clamp(16px, 4vw, 22px); /* 16px min prevents iOS zoom */
  text-align: center;
  border-radius: 14px;
  border: 2px solid var(--border-color);
  background: rgba(0, 0, 0, 0.2);
  color: white;
  width: 100%;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s;
  margin-top: 16px;
  min-height: 52px;
  touch-action: manipulation;
  /* Prevent iOS auto-zoom for real — 16px is the threshold */
}
input:focus {
  border-color: var(--primary-color);
}

/* ─── Hangul character ──────────────────────────────────────────────── */
.hangul-wrapper {
  display: flex;
  justify-content: center;
}
.hangul-container {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  padding: 8px;
}
.hangul {
  font-size: clamp(64px, 18vw, 100px);
  margin: 16px 0;
  font-weight: 800;
  text-shadow: 0 0 40px rgba(96, 165, 250, 0.3);
  transition: transform 0.2s;
  line-height: 1;
}
.hangul-container:hover .hangul { transform: scale(1.05); }
.hangul.error {
  color: var(--error-color);
  text-shadow: 0 0 40px rgba(239, 68, 68, 0.3);
  animation: shake 0.5s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

/* ─── Feedback / hints ──────────────────────────────────────────────── */
.hint {
  color: var(--error-color);
  margin-top: 12px;
  font-size: clamp(0.9rem, 3vw, 1.05rem);
  font-weight: 600;
  min-height: 24px;
}

/* ─── Stats header ──────────────────────────────────────────────────── */
.stats-container {
  display: flex;
  justify-content: space-between;
  margin-bottom: 12px;
  color: var(--text-muted);
  font-size: clamp(0.78rem, 2.5vw, 0.95rem);
  font-weight: 600;
  padding-right: 36px; /* room for close btn */
  flex-wrap: wrap;
  gap: 4px;
}

/* ─── Timer bar ─────────────────────────────────────────────────────── */
.progressBar {
  height: 6px;
  background: rgba(0, 0, 0, 0.3);
  margin: 10px 0 14px;
  border-radius: 4px;
  overflow: hidden;
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.2);
}
.progressInner {
  height: 100%;
  background: linear-gradient(90deg, #34d399, #10b981);
  width: 100%;
  transition: width 0.1s linear, background-color 0.3s;
}
.progressInner.warning { background: linear-gradient(90deg, #fcd34d, #fbbf24); }
.progressInner.danger  { background: linear-gradient(90deg, #fca5a5, #ef4444); }

/* ─── Utility ───────────────────────────────────────────────────────── */
.hidden { display: none !important; }

/* ─── Learning screen ───────────────────────────────────────────────── */
#learningScreen {
  /* Allow its content to scroll when many cards */
  overflow-y: auto;
}
.learning-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 12px;
  margin: 20px 0;
}
.flashcard {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 16px 8px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  touch-action: manipulation;
}
.flashcard:hover, .flashcard:active {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-4px);
  border-color: rgba(96, 165, 250, 0.5);
  box-shadow: 0 10px 20px -5px rgba(0, 0, 0, 0.3);
}
.flashcard .kr     { font-size: clamp(36px, 10vw, 48px); font-weight: 800; }
.flashcard .romaja { font-size: clamp(14px, 3.5vw, 18px); color: var(--text-muted); font-weight: 600; }
.flashcard .speaker {
  font-size: 13px;
  opacity: 0.5;
  transition: opacity 0.2s;
  display: flex;
  align-items: center;
  gap: 4px;
}
.flashcard:hover .speaker { opacity: 1; }

/* ─── Shake animation ───────────────────────────────────────────────── */
@keyframes shake {
  10%, 90%  { transform: translate3d(-1px, 0, 0); }
  20%, 80%  { transform: translate3d(2px, 0, 0); }
  30%, 50%, 70% { transform: translate3d(-4px, 0, 0); }
  40%, 60%  { transform: translate3d(4px, 0, 0); }
}

/* ─── Speaker icon ──────────────────────────────────────────────────── */
.speaker-icon {
  font-size: 26px;
  opacity: 0.5;
  transition: opacity 0.2s;
}
.hangul-container:hover .speaker-icon { opacity: 1; }

/* ─── Close button ──────────────────────────────────────────────────── */
.close-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  background: transparent;
  color: var(--text-muted);
  border: none;
  font-size: 18px;
  padding: 0;
  margin: 0;
  box-shadow: none;
  border-radius: 50%;
  width: 36px;
  height: 36px;
  min-height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  cursor: pointer;
  z-index: 50;
}
.close-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  transform: none;
  box-shadow: none;
}

/* ─── Progress badges ───────────────────────────────────────────────── */
.progress-badges {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 16px;
  overflow-y: auto;
  max-height: 200px;
  padding-bottom: 4px;
  width: 100%;
}
.progress-badges::-webkit-scrollbar { width: 4px; }
.progress-badges::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 3px;
}
.badge {
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 6px 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  transition: all 0.3s;
}
.badge.done {
  border-color: var(--success-color);
  background: rgba(16, 185, 129, 0.1);
}
.badge-char { font-size: 1.1rem; font-weight: 600; color: var(--text-main); }
.badge.done .badge-char { color: var(--success-color); }
.badge-dots { display: flex; gap: 4px; }
.badge-dots .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
}
.badge-dots .dot.filled { background: var(--success-color); }

/* ─── Level progress bar ────────────────────────────────────────────── */
.level-progress-container {
  margin-top: 12px;
  text-align: left;
  cursor: pointer;
  padding: 10px 12px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 10px;
  border: 1px solid var(--border-color);
  transition: background 0.2s;
}
.level-progress-container:hover { background: rgba(255, 255, 255, 0.1); }
.level-progress-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 600;
}
.level-progress-bar {
  height: 6px;
  background: rgba(0, 0, 0, 0.3);
  border-radius: 4px;
  overflow: hidden;
}
.level-progress-inner {
  height: 100%;
  background: var(--primary-color);
  width: 0%;
  transition: width 0.3s ease;
}

/* ─── Sidebar ───────────────────────────────────────────────────────── */
.sidebar {
  position: fixed;
  top: 0;
  right: -100%;
  width: 100%;
  max-width: 480px;
  height: 100%;
  height: 100dvh;
  background: rgba(15, 23, 42, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-left: 1px solid var(--border-color);
  padding: 24px 20px;
  transition: right 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 200;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.sidebar.open { right: 0; }
.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}
.sidebar-header h2 { margin: 0; font-size: 1.3rem; }

/* ─── Start screen mode selector ───────────────────────────────────── */
.lang-toggle { margin-bottom: 16px; }
.mode-selector { display: flex; flex-direction: column; gap: 10px; margin-top: 8px; }
.mode-btn {
  width: 100%;
  padding: 16px;
  margin: 0;
  font-size: clamp(1rem, 3.5vw, 1.15rem);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ─── Listening / recording pulse ───────────────────────────────────── */
@keyframes pulse-recording {
  0%   { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.4); }
  70%  { box-shadow: 0 0 0 12px rgba(59, 130, 246, 0); }
  100% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0); }
}
.listening-active {
  border-color: var(--primary-color) !important;
  animation: pulse-recording 1.5s infinite !important;
  background: rgba(59, 130, 246, 0.1) !important;
}

/* ─── Game panel scroll on very small screens ────────────────────────── */
#game {
  overflow-y: auto;
}

/* ─── Responsive tweaks ─────────────────────────────────────────────── */
@media (max-width: 400px) {
  .glass-panel { padding: 18px 14px; border-radius: 16px; }
  .hangul { margin: 10px 0; }
  .learning-grid { gap: 8px; }
  .badge { padding: 5px 8px; }
}

@media (min-height: 700px) {
  #app { justify-content: center; }
}