/* =========================================
   SHORTCUT TRAINER — CSS
   Dark-first, technical, developer-oriented
   ========================================= */

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

html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  scroll-behavior: smooth;
  font-size: 16px;
}

:root {
  --font-body: 'General Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', monospace;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Type scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.8125rem);
  --text-sm: clamp(0.8125rem, 0.78rem + 0.2vw, 0.875rem);
  --text-base: clamp(0.875rem, 0.85rem + 0.15vw, 0.9375rem);
  --text-lg: clamp(1rem, 0.95rem + 0.3vw, 1.125rem);
  --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
  --text-2xl: clamp(1.5rem, 1.2rem + 1.5vw, 2rem);

  /* Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* App Colors */
  --color-figma: #1abcfe;
  --color-sublime: #ff9800;
  --color-macos: #8e8e93;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 250ms cubic-bezier(0.16, 1, 0.3, 1);
}

/* === DARK THEME (default) === */
[data-theme="dark"] {
  --color-bg: #0f1117;
  --color-surface: #161822;
  --color-surface-2: #1c1e2e;
  --color-surface-3: #232538;
  --color-border: #2a2d42;
  --color-border-subtle: #1f2236;
  --color-text: #e1e2e8;
  --color-text-muted: #8b8d9e;
  --color-text-faint: #555770;
  --color-text-inverse: #0f1117;
  --color-primary: #1abcfe;
  --color-primary-hover: #47caff;
  --color-primary-muted: rgba(26, 188, 254, 0.12);
  --color-success: #4ade80;
  --color-error: #f87171;
  --color-warning: #fbbf24;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);

  --keycap-bg: linear-gradient(180deg, #2a2d42 0%, #1e2035 100%);
  --keycap-border: #383b54;
  --keycap-shadow: 0 2px 0 #0d0e16, 0 3px 4px rgba(0,0,0,0.4);
  --keycap-text: #c8cad8;

  --kb-key-bg: #1a1c2e;
  --kb-key-border: #2a2d42;
  --kb-key-text: #6b6e84;
  --kb-key-hover: #232538;
  --kb-key-active: rgba(26, 188, 254, 0.15);
  --kb-key-active-border: rgba(26, 188, 254, 0.4);
}

/* === LIGHT THEME === */
[data-theme="light"] {
  --color-bg: #f0f1f5;
  --color-surface: #ffffff;
  --color-surface-2: #f7f8fa;
  --color-surface-3: #edeef2;
  --color-border: #d8dae3;
  --color-border-subtle: #e8e9ef;
  --color-text: #1a1c2e;
  --color-text-muted: #6b6e84;
  --color-text-faint: #a0a3b5;
  --color-text-inverse: #ffffff;
  --color-primary: #0a8fd4;
  --color-primary-hover: #0778b8;
  --color-primary-muted: rgba(10, 143, 212, 0.08);
  --color-success: #22c55e;
  --color-error: #ef4444;
  --color-warning: #f59e0b;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);

  --keycap-bg: linear-gradient(180deg, #ffffff 0%, #f0f1f5 100%);
  --keycap-border: #d0d2dc;
  --keycap-shadow: 0 2px 0 #b8bac7, 0 3px 4px rgba(0,0,0,0.1);
  --keycap-text: #3a3c4e;

  --kb-key-bg: #f7f8fa;
  --kb-key-border: #d8dae3;
  --kb-key-text: #6b6e84;
  --kb-key-hover: #edeef2;
  --kb-key-active: rgba(10, 143, 212, 0.1);
  --kb-key-active-border: rgba(10, 143, 212, 0.4);
}

body {
  min-height: 100dvh;
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
}

a, button, input, select, textarea {
  transition: color var(--transition-fast),
              background var(--transition-fast),
              border-color var(--transition-fast),
              box-shadow var(--transition-fast);
}

button { cursor: pointer; background: none; border: none; font: inherit; color: inherit; }

::selection {
  background: rgba(26, 188, 254, 0.25);
  color: var(--color-text);
}

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* === HEADER === */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--space-3) var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.header-left { display: flex; align-items: center; }

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text);
  flex-shrink: 0;
}

.logo-text {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.02em;
}

.nav-tabs {
  display: flex;
  gap: var(--space-1);
  flex: 1;
  justify-content: center;
}

.nav-tab {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  white-space: nowrap;
}

.nav-tab:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

.nav-tab.active {
  color: var(--color-primary);
  background: var(--color-primary-muted);
}

.header-right {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}

.theme-toggle, .left-hand-toggle {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  position: relative;
}

.theme-toggle:hover, .left-hand-toggle:hover {
  background: var(--color-surface-2);
  color: var(--color-text);
}

.left-hand-toggle.active {
  color: var(--color-primary);
  background: var(--color-primary-muted);
}

.left-hand-badge {
  position: absolute;
  top: -2px;
  right: -4px;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 700;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  padding: 1px 4px;
  border-radius: 6px;
  line-height: 1.2;
}

/* === MAIN === */
.main {
  flex: 1;
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--space-6);
  width: 100%;
}

.tab-content { display: none; }
.tab-content.active { display: block; }

/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-5);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn-primary:hover { background: var(--color-primary-hover); }

.btn-show {
  background: var(--color-surface-3);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
}
.btn-show:hover { background: var(--color-border); }

.btn-learn {
  background: var(--color-surface-3);
  color: var(--color-warning);
  border: 1px solid rgba(251, 191, 36, 0.25);
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
}
.btn-learn:hover {
  background: rgba(251, 191, 36, 0.12);
  border-color: rgba(251, 191, 36, 0.4);
}

.btn-remember {
  background: var(--color-success);
  color: var(--color-text-inverse);
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
}
.btn-remember:hover {
  background: #22c55e;
  filter: brightness(1.1);
}

/* === PLATFORM TOGGLE === */
.platform-toggle {
  display: flex;
  gap: 2px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: 2px;
}

.platform-btn {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: calc(var(--radius-md) - 2px);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.platform-btn:hover {
  color: var(--color-text);
}

.platform-btn.active {
  background: var(--color-primary-muted);
  color: var(--color-primary);
}

.btn-reset {
  background: transparent;
  color: var(--color-text-faint);
  border: 1px solid var(--color-border-subtle);
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-3);
  width: 100%;
}
.btn-reset:hover { color: var(--color-error); border-color: var(--color-error); }

.btn-start {
  padding: var(--space-3) var(--space-8);
  font-size: var(--text-base);
}

/* === KEYCAP STYLING === */
.keycap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  padding: 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--keycap-text);
  background: var(--keycap-bg);
  border: 1px solid var(--keycap-border);
  border-radius: 6px;
  box-shadow: var(--keycap-shadow);
  line-height: 1;
  white-space: nowrap;
  vertical-align: middle;
}

.keycap-display {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  justify-content: center;
}

.keycap-display .keycap {
  min-width: 36px;
  height: 36px;
  font-size: var(--text-sm);
  padding: 0 var(--space-3);
}

.keycap-plus {
  color: var(--color-text-faint);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
}

.keycap.keycap-animated {
  animation: keycapPress 0.4s ease-out;
}

@keyframes keycapPress {
  0% { transform: scale(0.8) translateY(4px); opacity: 0; }
  50% { transform: scale(1.05) translateY(-2px); }
  100% { transform: scale(1) translateY(0); opacity: 1; }
}

/* === TRAINING === */
.training-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: var(--space-6);
  align-items: start;
}

.training-sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.training-filters, .training-stats {
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.filter-title {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-faint);
  margin-bottom: var(--space-3);
}

.app-filter-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.app-filter-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  cursor: pointer;
  padding: var(--space-1) 0;
  color: var(--color-text-muted);
}

.app-filter-item:hover { color: var(--color-text); }

.app-filter-item input[type="checkbox"] {
  width: 14px;
  height: 14px;
  accent-color: var(--color-primary);
}

.app-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-1) 0;
}

.stat-label { font-size: var(--text-xs); color: var(--color-text-muted); }
.stat-value { font-family: var(--font-mono); font-size: var(--text-sm); font-weight: 600; color: var(--color-text); }

.progress-bar-container {
  height: 4px;
  background: var(--color-surface-3);
  border-radius: 2px;
  margin-top: var(--space-3);
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: var(--color-primary);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.training-main {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 400px;
}

.flashcard-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-6);
  width: 100%;
  max-width: 560px;
}

.flashcard {
  width: 100%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8) var(--space-6);
  text-align: center;
  min-height: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
}

.flashcard-app {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  display: none;
}

.flashcard-app.figma { color: var(--color-figma); background: rgba(26,188,254,0.1); border: 1px solid rgba(26,188,254,0.2); display: inline-block; }
.flashcard-app.sublime { color: var(--color-sublime); background: rgba(255,152,0,0.1); border: 1px solid rgba(255,152,0,0.2); display: inline-block; }
.flashcard-app.macos { color: var(--color-macos); background: rgba(142,142,147,0.1); border: 1px solid rgba(142,142,147,0.2); display: inline-block; }

.flashcard-question {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.3;
}

.flashcard-answer {
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border-subtle);
  width: 100%;
}

.flashcard-rating {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  justify-content: center;
}

.flashcard-done {
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--text-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
}

/* === INPUT ZONE (keyboard input area) === */
.input-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-4) var(--space-4);
  margin-top: var(--space-2);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface-2);
  transition: border-color var(--transition-normal),
              background var(--transition-normal),
              box-shadow var(--transition-normal);
  min-height: 72px;
  position: relative;
}

.input-zone-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-faint);
}

.pressed-display {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  justify-content: center;
  min-height: 36px;
}

.pressed-display .keycap {
  min-width: 36px;
  height: 36px;
  font-size: var(--text-sm);
  padding: 0 var(--space-3);
}

.input-placeholder {
  color: var(--color-text-faint);
  font-size: var(--text-sm);
  font-style: italic;
}

.step-hint {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-1);
  transition: color var(--transition-fast);
}

.step-hint.step-ok {
  color: var(--color-success);
}

/* Correct state */
.input-zone.correct {
  border-color: var(--color-success);
  border-style: solid;
  background: rgba(74, 222, 128, 0.08);
  box-shadow: 0 0 0 4px rgba(74, 222, 128, 0.12);
  animation: pulseCorrect 0.5s ease-out;
}

.input-zone.correct .input-zone-label {
  color: var(--color-success);
}

.input-zone.correct .keycap {
  border-color: var(--color-success);
  color: var(--color-success);
}

/* Wrong state */
.input-zone.wrong {
  border-color: var(--color-error);
  border-style: solid;
  background: rgba(248, 113, 113, 0.08);
  box-shadow: 0 0 0 4px rgba(248, 113, 113, 0.1);
  animation: shakeWrong 0.4s ease-out;
}

.input-zone.wrong .input-zone-label {
  color: var(--color-error);
}

.input-zone.wrong .keycap {
  border-color: var(--color-error);
  color: var(--color-error);
}

/* Answer label */
.answer-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-success);
  margin-bottom: var(--space-2);
}

/* Skip button */
.btn-skip {
  background: transparent;
  color: var(--color-text-faint);
  border: 1px solid var(--color-border-subtle);
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-4);
}
.btn-skip:hover {
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

@keyframes pulseCorrect {
  0% { box-shadow: 0 0 0 0 rgba(74, 222, 128, 0.4); }
  50% { box-shadow: 0 0 0 8px rgba(74, 222, 128, 0.15); }
  100% { box-shadow: 0 0 0 4px rgba(74, 222, 128, 0.12); }
}

@keyframes shakeWrong {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

/* === REFERENCE === */
.reference-header {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.search-input {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  font-family: var(--font-body);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  outline: none;
}

.search-input::placeholder { color: var(--color-text-faint); }
.search-input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-muted); }

.app-pills {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.app-pill {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
}

.app-pill:hover { color: var(--color-text); background: var(--color-surface-2); }
.app-pill.active { color: var(--color-primary); background: var(--color-primary-muted); border-color: transparent; }
.app-pill.figma.active { color: var(--color-figma); background: rgba(26,188,254,0.1); }
.app-pill.sublime.active { color: var(--color-sublime); background: rgba(255,152,0,0.1); }
.app-pill.macos.active { color: var(--color-macos); background: rgba(142,142,147,0.1); }

.reference-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-4);
}

.ref-category {
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.ref-category-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.ref-category-app {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 2px 6px;
  border-radius: 4px;
}

.ref-category-app.figma { color: var(--color-figma); background: rgba(26,188,254,0.1); }
.ref-category-app.sublime { color: var(--color-sublime); background: rgba(255,152,0,0.1); }
.ref-category-app.macos { color: var(--color-macos); background: rgba(142,142,147,0.1); }

.ref-category-name {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}

.ref-shortcut-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.ref-shortcut-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-2);
  border-radius: var(--radius-sm);
  gap: var(--space-3);
}

.ref-shortcut-item:hover {
  background: var(--color-surface-2);
}

.ref-shortcut-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  flex: 1;
  min-width: 0;
}

.ref-shortcut-keys {
  display: flex;
  align-items: center;
  gap: 3px;
  flex-shrink: 0;
}

.ref-shortcut-keys .keycap {
  min-width: 22px;
  height: 22px;
  font-size: 11px;
  padding: 0 5px;
}

/* === CONFLICTS === */
.conflicts-header {
  margin-bottom: var(--space-6);
}

.section-title {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.section-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.conflict-filters {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.conflict-filter {
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
}

.conflict-filter:hover { color: var(--color-text); }
.conflict-filter.active { color: var(--color-primary); background: var(--color-primary-muted); border-color: transparent; }

.conflicts-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-subtle);
}

.conflicts-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

.conflicts-table thead th {
  padding: var(--space-3) var(--space-4);
  text-align: left;
  font-weight: 600;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  border-bottom: 1px solid var(--color-border);
}

.conflicts-table thead .col-figma { color: var(--color-figma); }
.conflicts-table thead .col-sublime { color: var(--color-sublime); }
.conflicts-table thead .col-macos { color: var(--color-macos); }

.conflicts-table tbody td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border-subtle);
  vertical-align: middle;
}

.conflicts-table tbody tr:last-child td { border-bottom: none; }

.conflicts-table tbody tr:hover {
  background: var(--color-surface-2);
}

.conflict-cell-figma { color: var(--color-figma); }
.conflict-cell-sublime { color: var(--color-sublime); }
.conflict-cell-macos { color: var(--color-macos); }
.conflict-cell-empty { color: var(--color-text-faint); }

/* === KEYBOARD VISUAL === */
.keyboard-header {
  margin-bottom: var(--space-6);
}

.keyboard-container {
  display: flex;
  justify-content: center;
  padding: var(--space-4) 0;
  overflow-x: auto;
}

.keyboard-visual {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-xl);
  min-width: fit-content;
}

.kb-row {
  display: flex;
  gap: 5px;
}

.kb-key {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 38px;
  min-width: 38px;
  padding: 0 6px;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--kb-key-text);
  background: var(--kb-key-bg);
  border: 1px solid var(--kb-key-border);
  border-radius: 6px;
  cursor: pointer;
  position: relative;
  user-select: none;
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.kb-key:hover {
  background: var(--kb-key-hover);
  color: var(--color-text);
  border-color: var(--color-border);
  z-index: 2;
}

.kb-key.active {
  background: var(--kb-key-active);
  border-color: var(--kb-key-active-border);
  color: var(--color-primary);
}

/* App-specific keyboard colors */
.keyboard-visual.app-figma .kb-key.active {
  background: rgba(26, 188, 254, 0.12);
  border-color: rgba(26, 188, 254, 0.4);
  color: #1abcfe;
}
.keyboard-visual.app-sublime .kb-key.active {
  background: rgba(255, 152, 0, 0.12);
  border-color: rgba(255, 152, 0, 0.4);
  color: #ff9800;
}
.keyboard-visual.app-macos .kb-key.active {
  background: rgba(142, 142, 147, 0.12);
  border-color: rgba(142, 142, 147, 0.4);
  color: #8e8e93;
}

.kb-key.left-zone {
  box-shadow: inset 0 0 0 2px rgba(26, 188, 254, 0.15);
}

.kb-key.left-zone-highlight {
  background: rgba(26, 188, 254, 0.08);
  border-color: rgba(26, 188, 254, 0.25);
}

.kb-key-label {
  font-size: 10px;
  line-height: 1.1;
  text-align: center;
}

/* Key tooltip */
.keyboard-tooltip {
  position: fixed;
  z-index: 200;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-3) var(--space-4);
  box-shadow: var(--shadow-lg);
  font-size: var(--text-xs);
  max-width: 300px;
  pointer-events: none;
}

.tooltip-title {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.tooltip-shortcut {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 2px 0;
  color: var(--color-text-muted);
}

.tooltip-shortcut-app {
  font-weight: 600;
}

.tooltip-shortcut-app.figma { color: var(--color-figma); }
.tooltip-shortcut-app.sublime { color: var(--color-sublime); }
.tooltip-shortcut-app.macos { color: var(--color-macos); }

/* === FOOTER === */
.footer {
  padding: var(--space-4) var(--space-6);
  text-align: center;
  border-top: 1px solid var(--color-border-subtle);
}

.footer a {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-decoration: none;
}

.footer a:hover { color: var(--color-text-muted); text-decoration: underline; }

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-4);
  }

  .nav-tabs {
    order: 3;
    width: 100%;
    overflow-x: auto;
    justify-content: flex-start;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .nav-tabs::-webkit-scrollbar { display: none; }

  .nav-tab {
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-xs);
  }

  .main { padding: var(--space-4); }

  .training-layout {
    grid-template-columns: 1fr;
  }

  .training-sidebar {
    order: 2;
  }

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

  .flashcard {
    padding: var(--space-6) var(--space-4);
    min-height: 160px;
  }

  .flashcard-question {
    font-size: var(--text-lg);
  }
}

@media (max-width: 480px) {
  .logo-text { display: none; }
  .platform-toggle {
    order: -1;
  }
  .platform-btn {
    padding: var(--space-1) var(--space-2);
    font-size: 10px;
  }
}

/* Scrollbar styling */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-faint); }

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.3s ease-out;
}