/* ===== CSS Custom Properties (Themes) ===== */
:root {
  --bg-primary: #0f0f1a;
  --bg-card: #16162a;
  --bg-controls: rgba(15, 15, 26, 0.85);
  --bg-settings: #1a1a2e;
  --text-primary: #e8e8f0;
  --text-muted: #7878a0;
  --text-meaning: #c0c0e0;
  --accent: #6c5ce7;
  --accent-hover: #7f71ed;
  --accent-glow: rgba(108, 92, 231, 0.25);
  --danger: #e74c3c;
  --divider: rgba(108, 92, 231, 0.3);
  --shadow: rgba(0, 0, 0, 0.4);
  --toast-bg: #2a2a4a;
  --border: rgba(255, 255, 255, 0.08);
  --font-word: 'Noto Serif', 'Georgia', 'Times New Roman', serif;
  --font-ui: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --transition-card: 0.5s;
  --radius: 12px;
}

[data-theme="light"] {
  --bg-primary: #f0efe8;
  --bg-card: #ffffff;
  --bg-controls: rgba(240, 239, 232, 0.9);
  --bg-settings: #f8f8f4;
  --text-primary: #1a1a2e;
  --text-muted: #666688;
  --text-meaning: #3a3a5e;
  --accent: #5a4bd4;
  --accent-hover: #6c5ce7;
  --accent-glow: rgba(90, 75, 212, 0.15);
  --divider: rgba(90, 75, 212, 0.25);
  --shadow: rgba(0, 0, 0, 0.1);
  --toast-bg: #ffffff;
  --border: rgba(0, 0, 0, 0.08);
}

@media (prefers-color-scheme: light) {
  [data-theme="auto"] {
    --bg-primary: #f0efe8;
    --bg-card: #ffffff;
    --bg-controls: rgba(240, 239, 232, 0.9);
    --bg-settings: #f8f8f4;
    --text-primary: #1a1a2e;
    --text-muted: #666688;
    --text-meaning: #3a3a5e;
    --accent: #5a4bd4;
    --accent-hover: #6c5ce7;
    --accent-glow: rgba(90, 75, 212, 0.15);
    --divider: rgba(90, 75, 212, 0.25);
    --shadow: rgba(0, 0, 0, 0.1);
    --toast-bg: #ffffff;
    --border: rgba(0, 0, 0, 0.08);
  }
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font-ui);
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  user-select: none;
}

/* ===== Progress Bar ===== */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 100;
  background: transparent;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.1s linear;
  box-shadow: 0 0 8px var(--accent-glow);
}

/* ===== Card Container ===== */
.card-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  padding: 2rem;
  position: relative;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  text-align: center;
  max-width: 800px;
  width: 100%;
  padding: 2rem;
}

/* Card transitions */
.card.fade-out {
  animation: fadeOut var(--transition-card) ease forwards;
}
.card.fade-in {
  animation: fadeIn var(--transition-card) ease forwards;
}
.card.slide-out-left {
  animation: slideOutLeft var(--transition-card) ease forwards;
}
.card.slide-in-right {
  animation: slideInRight var(--transition-card) ease forwards;
}
.card.slide-out-right {
  animation: slideOutRight var(--transition-card) ease forwards;
}
.card.slide-in-left {
  animation: slideInLeft var(--transition-card) ease forwards;
}

@keyframes fadeOut {
  from { opacity: 1; transform: scale(1); }
  to { opacity: 0; transform: scale(0.96); }
}
@keyframes fadeIn {
  from { opacity: 0; transform: scale(1.04); }
  to { opacity: 1; transform: scale(1); }
}
@keyframes slideOutLeft {
  from { opacity: 1; transform: translateX(0); }
  to { opacity: 0; transform: translateX(-80px); }
}
@keyframes slideInRight {
  from { opacity: 0; transform: translateX(80px); }
  to { opacity: 1; transform: translateX(0); }
}
@keyframes slideOutRight {
  from { opacity: 1; transform: translateX(0); }
  to { opacity: 0; transform: translateX(80px); }
}
@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-80px); }
  to { opacity: 1; transform: translateX(0); }
}

/* Card Elements */
.card-emoji {
  font-size: clamp(5rem, 12vw, 10rem);
  line-height: 1.1;
  margin-bottom: 0.5rem;
  filter: drop-shadow(0 4px 12px var(--shadow));
}

.card-word {
  font-family: 'Noto Serif', var(--font-word);
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  line-height: 1.3;
  font-feature-settings: "mark" 1;
  -webkit-font-feature-settings: "mark" 1;
}

.card-romanization {
  font-size: clamp(1rem, 2.5vw, 1.5rem);
  color: var(--text-muted);
  font-style: italic;
}

.card-romanization:empty {
  display: none;
}

.card-divider {
  width: 60px;
  height: 2px;
  background: var(--divider);
  margin: 0.8rem 0;
  border-radius: 1px;
}

.card-meaning {
  font-size: clamp(1.8rem, 4vw, 3rem);
  color: var(--text-meaning);
  font-weight: 400;
}

.card-pos {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-top: 0.3rem;
}

.card-pos:empty {
  display: none;
}

.card-footer {
  position: fixed;
  bottom: 70px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: space-between;
  padding: 0 2rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.card-topic, .card-counter {
  background: var(--bg-controls);
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  backdrop-filter: blur(8px);
}

/* ===== Controls Bar ===== */
.controls {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  padding: 0.8rem 1.5rem;
  background: var(--bg-controls);
  backdrop-filter: blur(12px);
  border-top: 1px solid var(--border);
  z-index: 50;
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.controls.hidden {
  opacity: 0;
  transform: translateY(100%);
  pointer-events: none;
}

.controls-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.ctrl-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background: transparent;
  color: var(--text-primary);
  cursor: pointer;
  transition: background 0.2s, color 0.2s, transform 0.15s;
}

.ctrl-btn:hover {
  background: var(--accent-glow);
  color: var(--accent);
}

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

.ctrl-btn--primary {
  width: 48px;
  height: 48px;
  background: var(--accent);
  color: #fff;
}

.ctrl-btn--primary:hover {
  background: var(--accent-hover);
  color: #fff;
}

/* ===== Weight feedback flash ===== */
.card-container.flash-more {
  animation: flashMore 0.4s ease;
}
.card-container.flash-less {
  animation: flashLess 0.4s ease;
}

@keyframes flashMore {
  0%, 100% { background: transparent; }
  50% { background: rgba(46, 213, 115, 0.08); }
}
@keyframes flashLess {
  0%, 100% { background: transparent; }
  50% { background: rgba(231, 76, 60, 0.08); }
}

/* ===== Settings Panel ===== */
.settings-panel {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
}

.settings-panel.open {
  display: flex;
}

.settings-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.settings-content {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: min(420px, 90vw);
  background: var(--bg-settings);
  overflow-y: auto;
  padding: 1.5rem;
  box-shadow: -4px 0 24px var(--shadow);
  animation: slideInSettings 0.3s ease;
}

@keyframes slideInSettings {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.settings-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.settings-header h2 {
  font-size: 1.3rem;
  font-weight: 600;
}

.settings-section {
  margin-bottom: 1.5rem;
}

.settings-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.settings-select {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: var(--font-ui);
  cursor: pointer;
}

.settings-select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.settings-checks {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.settings-checks label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
}

.settings-checks label:has(input:checked) {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
}

.settings-checks input[type="checkbox"] {
  display: none;
}

.settings-slider-row {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.settings-range {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}

.settings-value {
  min-width: 3rem;
  text-align: right;
  font-weight: 600;
  font-size: 0.95rem;
}

.settings-toggles {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.toggle-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  cursor: pointer;
}

.toggle-row input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
  cursor: pointer;
}

.settings-progress-btns {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.settings-btn {
  padding: 0.55rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-family: var(--font-ui);
  cursor: pointer;
  text-align: left;
  transition: background 0.2s, border-color 0.2s;
}

.settings-btn:hover {
  border-color: var(--accent);
  background: var(--accent-glow);
}

.settings-btn--danger {
  color: var(--danger);
}

.settings-btn--danger:hover {
  border-color: var(--danger);
  background: rgba(231, 76, 60, 0.1);
}

.share-code-area {
  margin-top: 0.5rem;
}

.share-code-text {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: monospace;
  font-size: 0.8rem;
  resize: vertical;
  margin-bottom: 0.4rem;
}

.share-code-text:focus {
  outline: 2px solid var(--accent);
}

.settings-coffee {
  text-align: center;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.coffee-link {
  display: inline-block;
  padding: 0.7rem 1.5rem;
  background: #ffdd00;
  color: #1a1a1a;
  font-weight: 700;
  font-size: 1rem;
  border-radius: 30px;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s;
}

.coffee-link:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(255, 221, 0, 0.3);
}

.settings-note {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  line-height: 1.4;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--toast-bg);
  color: var(--text-primary);
  padding: 0.6rem 1.2rem;
  border-radius: 30px;
  font-size: 0.85rem;
  box-shadow: 0 4px 20px var(--shadow);
  border: 1px solid var(--border);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s, transform 0.3s;
  z-index: 300;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .card {
    padding: 1rem;
  }

  .card-footer {
    bottom: 60px;
    padding: 0 1rem;
    font-size: 0.75rem;
  }

  .controls {
    gap: 0.8rem;
    padding: 0.5rem 0.8rem;
  }

  .ctrl-btn {
    width: 36px;
    height: 36px;
  }

  .ctrl-btn--primary {
    width: 42px;
    height: 42px;
  }
}

/* ===== Fullscreen adjustments ===== */
:fullscreen .controls {
  bottom: 0;
}

/* ===== Scrollbar for settings ===== */
.settings-content::-webkit-scrollbar {
  width: 6px;
}

.settings-content::-webkit-scrollbar-track {
  background: transparent;
}

.settings-content::-webkit-scrollbar-thumb {
  background: var(--text-muted);
  border-radius: 3px;
}

.settings-content::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}