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

:root {
  --bg: #0f0e0c;
  --surface: #191816;
  --border: #2a2825;
  --muted: #4a4845;
  --text: #e8e4dc;
  --sub: #9a948a;
  --accent: #c9a96e;
  --done: #4e8c62;
  --forgot: #8c4e4e;
  --done-bg: #1a2e20;
  --forgot-bg: #2e1a1a;
  --sidebar-w: 340px;
  --header-h: 58px;
  --mob-bar-h: 64px;
}

html,
body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: "DM Sans", sans-serif;
  -webkit-tap-highlight-color: transparent;
}

/* ── APP SHELL ──────────────────────────────────────────────────────────────── */
#app {
  display: grid;
  grid-template-rows: var(--header-h) 1fr;
  height: 100dvh; /* dynamic viewport height — handles mobile browser chrome */
}

/* ── HEADER ─────────────────────────────────────────────────────────────────── */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  height: var(--header-h);
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  flex-shrink: 0;
  z-index: 10;
}

.brand {
  font-family: "Playfair Display", serif;
  font-size: 1.3rem;
  letter-spacing: 0.05em;
  color: var(--accent);
  white-space: nowrap;
}
.brand span {
  font-style: italic;
  color: var(--sub);
  font-size: 0.8rem;
  font-family: "DM Mono", monospace;
  margin-left: 8px;
  font-weight: 300;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

select {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 28px 6px 10px;
  border-radius: 6px;
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%234a4845'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}
select:focus {
  outline: none;
  border-color: var(--accent);
}

.progress-pill {
  font-family: "DM Mono", monospace;
  font-size: 0.72rem;
  color: var(--sub);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 4px 12px;
  white-space: nowrap;
}
.progress-pill b {
  color: var(--accent);
}

/* ── BODY LAYOUT ────────────────────────────────────────────────────────────── */
.body {
  display: flex;
  overflow: hidden;
  height: 100%;
  position: relative;
}

/* ── WORD LIST PANEL ────────────────────────────────────────────────────────── */
#word-list-panel {
  width: 220px;
  flex-shrink: 0;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* Mobile toggle button — hidden on desktop */
#panel-toggle {
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: var(--surface);
  border: none;
  border-bottom: 1px solid var(--border);
  color: var(--sub);
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  cursor: pointer;
  width: 100%;
  flex-shrink: 0;
}
#panel-chevron {
  transition: transform 0.2s;
  color: var(--muted);
}
#word-list-panel.collapsed #panel-chevron {
  transform: rotate(-90deg);
}

#word-list {
  flex: 1;
  overflow-y: auto;
  padding: 10px 6px;
}
#word-list::-webkit-scrollbar {
  width: 4px;
}
#word-list::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

.word-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.82rem;
  font-family: "DM Mono", monospace;
  color: var(--sub);
  transition:
    background 0.12s,
    color 0.12s;
}
.word-item:hover {
  background: var(--border);
  color: var(--text);
}
.word-item.active {
  background: #221f1a;
  color: var(--accent);
}
.word-item .status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  flex-shrink: 0;
  background: var(--border);
  transition: background 0.2s;
}
.word-item.done .status-dot {
  background: var(--done);
}
.word-item.forgot .status-dot {
  background: var(--forgot);
}
.word-item.done {
  color: var(--done);
}
.word-item.forgot {
  color: var(--forgot);
}

/* ── STAGE ──────────────────────────────────────────────────────────────────── */
#stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 24px;
  overflow-y: auto;
  min-width: 0; /* prevent flex overflow */
}

.word-display {
  text-align: center;
  max-width: 520px;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.word-number {
  font-family: "DM Mono", monospace;
  font-size: 0.7rem;
  color: var(--muted);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 18px;
}

.big-word {
  font-family: "Playfair Display", serif;
  font-size: clamp(2.4rem, 7vw, 4.8rem);
  line-height: 1.1;
  color: var(--text);
  word-break: break-word;
}
.big-word.status-done {
  color: var(--done);
}
.big-word.status-forgot {
  color: var(--forgot);
}

.phonetic {
  font-family: "DM Mono", monospace;
  font-size: 0.88rem;
  color: var(--muted);
  margin-top: 10px;
  letter-spacing: 0.05em;
  min-height: 1.4em;
}

.forms-strip {
  display: flex;
  gap: 7px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 24px;
}
.form-tag {
  font-family: "DM Mono", monospace;
  font-size: 0.7rem;
  padding: 4px 9px;
  border-radius: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--sub);
}
.form-tag b {
  color: var(--accent);
  margin-right: 4px;
}

/* Desktop nav buttons */
.nav-arrows {
  display: flex;
  gap: 10px;
  margin-top: 36px;
}
.nav-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--sub);
  padding: 7px 18px;
  border-radius: 6px;
  cursor: pointer;
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  transition:
    border-color 0.15s,
    color 0.15s;
}
.nav-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}
.nav-btn:disabled {
  opacity: 0.28;
  cursor: default;
}

/* Keyboard hint bar */
.kbd-bar {
  display: flex;
  gap: 14px;
  margin-top: 44px;
  flex-wrap: wrap;
  justify-content: center;
}
.kbd-hint {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--muted);
}
kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 24px;
  height: 24px;
  padding: 0 4px;
  border-radius: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-family: "DM Mono", monospace;
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--text);
  box-shadow: 0 2px 0 var(--border);
}

/* ── SIDEBAR ────────────────────────────────────────────────────────────────── */
#sidebar {
  width: 0;
  overflow: hidden;
  flex-shrink: 0;
  border-left: 0px solid var(--border);
  transition:
    width 0.3s ease,
    border-left 0.3s ease;
  display: flex;
  flex-direction: column;
}
#sidebar.open {
  width: var(--sidebar-w);
  border-left: 1px solid var(--border);
}

.sidebar-inner {
  width: var(--sidebar-w);
  padding: 26px 22px;
  overflow-y: auto;
  height: 100%;
}
.sidebar-inner::-webkit-scrollbar {
  width: 4px;
}
.sidebar-inner::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

.sidebar-label {
  font-family: "DM Mono", monospace;
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.sidebar-word {
  font-family: "Playfair Display", serif;
  font-size: 1.5rem;
  color: var(--accent);
  margin-bottom: 6px;
}
.meaning-block {
  margin-bottom: 16px;
}
.meaning-index {
  font-family: "DM Mono", monospace;
  font-size: 0.68rem;
  color: var(--muted);
  margin-bottom: 4px;
}
.meaning-text {
  font-size: 0.88rem;
  line-height: 1.65;
  color: var(--text);
  border-left: 2px solid var(--border);
  padding-left: 11px;
}
.sidebar-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 18px 0;
}
.forms-section .form-row {
  display: flex;
  gap: 8px;
  align-items: baseline;
  margin-bottom: 8px;
}
.form-type {
  font-family: "DM Mono", monospace;
  font-size: 0.68rem;
  color: var(--muted);
  min-width: 50px;
}
.form-word {
  font-family: "Playfair Display", serif;
  font-size: 1rem;
  color: var(--text);
}
.status-banner {
  margin-top: 18px;
  padding: 9px 13px;
  border-radius: 6px;
  font-family: "DM Mono", monospace;
  font-size: 0.76rem;
  display: none;
}
.status-banner.done {
  background: var(--done-bg);
  color: var(--done);
  display: block;
}
.status-banner.forgot {
  background: var(--forgot-bg);
  color: var(--forgot);
  display: block;
}

/* ── EMPTY / LOADING ────────────────────────────────────────────────────────── */
#loading-msg,
.empty-state {
  text-align: center;
  color: var(--muted);
  font-family: "Playfair Display", serif;
  font-style: italic;
  font-size: 1.1rem;
}

/* ── MOBILE ACTION BAR ──────────────────────────────────────────────────────── */
/* Hidden on desktop, shown on mobile */
#mobile-actions {
  display: none;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--mob-bar-h);
  background: var(--surface);
  border-top: 1px solid var(--border);
  z-index: 40;
  align-items: stretch;
}
.mob-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  background: none;
  border: none;
  color: var(--sub);
  font-family: "DM Mono", monospace;
  font-size: 0.6rem;
  letter-spacing: 0.05em;
  cursor: pointer;
  padding: 8px 0;
  transition:
    color 0.15s,
    background 0.15s;
  -webkit-tap-highlight-color: transparent;
}
.mob-btn:active {
  background: var(--border);
}
.mob-btn.mob-done {
  color: var(--done);
}
.mob-btn.mob-forgot {
  color: var(--forgot);
}
.mob-btn.mob-reset {
  color: var(--muted);
}

/* ── SIDEBAR OVERLAY (mobile) ───────────────────────────────────────────────── */
#sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 29;
  backdrop-filter: blur(2px);
}
#sidebar-overlay.visible {
  display: block;
}

/* ── TOAST ──────────────────────────────────────────────────────────────────── */
#toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 9px 18px;
  border-radius: 8px;
  font-family: "DM Mono", monospace;
  font-size: 0.78rem;
  opacity: 0;
  transition:
    opacity 0.2s,
    transform 0.2s;
  pointer-events: none;
  z-index: 100;
  white-space: nowrap;
}
#toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
#toast.green {
  border-color: var(--done);
  color: var(--done);
}
#toast.red {
  border-color: var(--forgot);
  color: var(--forgot);
}
#toast.amber {
  border-color: var(--accent);
  color: var(--accent);
}

/* ── RESPONSIVE: TABLET (≤ 900px) ──────────────────────────────────────────── */
@media (max-width: 900px) {
  :root {
    --sidebar-w: 280px;
  }

  .brand span {
    display: none;
  } /* hide subtitle on smaller screens */

  #word-list-panel {
    width: 180px;
  }
}

/* ── RESPONSIVE: MOBILE (≤ 640px) ──────────────────────────────────────────── */
@media (max-width: 640px) {
  :root {
    --sidebar-w: 100vw; /* sidebar takes full width on mobile */
    --header-h: 52px;
  }

  /* App needs room for mobile action bar at bottom */
  #app {
    grid-template-rows: var(--header-h) 1fr;
    padding-bottom: var(--mob-bar-h);
  }

  /* Header tighter */
  header {
    padding: 0 16px;
  }
  .brand {
    font-size: 1.1rem;
  }
  .brand span {
    display: none;
  }
  .progress-pill {
    font-size: 0.68rem;
    padding: 4px 9px;
  }

  /* Body is now single column: word list stacked above stage */
  .body {
    flex-direction: column;
    overflow: hidden;
  }

  /* Word list panel: collapsible strip */
  #word-list-panel {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    max-height: 200px;
    transition: max-height 0.3s ease;
    overflow: hidden;
  }
  #word-list-panel.collapsed {
    max-height: 40px; /* just the toggle button height */
  }
  #panel-toggle {
    display: flex;
  }
  #word-list {
    padding: 6px 4px;
  }
  .word-item {
    padding: 7px 10px;
    font-size: 0.78rem;
  }

  /* Stage fills remaining space */
  #stage {
    flex: 1;
    padding: 24px 16px;
    overflow-y: auto;
    justify-content: flex-start;
    padding-top: 32px;
  }

  .big-word {
    font-size: clamp(2rem, 10vw, 3rem);
  }
  .phonetic {
    font-size: 0.82rem;
  }

  .forms-strip {
    gap: 5px;
    margin-top: 18px;
  }
  .form-tag {
    font-size: 0.66rem;
    padding: 3px 7px;
  }

  /* Hide desktop nav and kbd hints on mobile */
  .nav-arrows {
    display: none;
  }
  .kbd-bar {
    display: none;
  }

  /* Show mobile action bar */
  #mobile-actions {
    display: flex;
  }

  /* Sidebar overlays from the right on mobile */
  #sidebar {
    position: fixed;
    top: var(--header-h);
    right: 0;
    bottom: var(--mob-bar-h);
    width: 0;
    border-left: none;
    z-index: 30;
    background: var(--surface);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.4);
    transition: width 0.3s ease;
  }
  #sidebar.open {
    width: min(340px, 92vw);
    border-left: 1px solid var(--border);
  }
  .sidebar-inner {
    width: min(340px, 92vw);
  }

  /* Toast sits above action bar */
  #toast {
    bottom: calc(var(--mob-bar-h) + 12px);
  }
}

/* ── RESPONSIVE: VERY SMALL (≤ 380px) ──────────────────────────────────────── */
@media (max-width: 380px) {
  .brand {
    font-size: 1rem;
  }
  .mob-btn span {
    display: none;
  } /* icon only on very small screens */
  :root {
    --mob-bar-h: 52px;
  }
}