/* ============================================================
   BitPitch — 8-bit Theme
   All measurements in px for pixel-perfect retro look.
   No border-radius anywhere — square corners only.
   ============================================================ */

/* ---------- Color palette ---------- */
:root {
  --bg:        #0a0a0a;
  --panel:     #111827;
  --border:    #1e3a5f;
  --green:     #39ff14;
  --blue:      #00d4ff;
  --yellow:    #ffe600;
  --red:       #ff2d55;
  --purple:    #bf5fff;
  --text:      #e8e8e8;
  --text-dim:  #666;
  --shadow:    4px 4px 0px #000;
}

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

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: 'Press Start 2P', monospace;
  font-size: 10px;
  line-height: 1.8;
  overflow-x: hidden;
}

/* ---------- Screens ---------- */
.screen {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 24px 16px;
  gap: 20px;
}

.hidden {
  display: none !important;
}

/* ---------- HOME: Header ---------- */
.header {
  text-align: center;
  padding: 16px 0 8px;
}

.title {
  font-size: 32px;
  color: var(--yellow);
  text-shadow: 4px 4px 0 #7a6000, 8px 8px 0 #000;
  letter-spacing: 4px;
}

.title-accent {
  color: var(--green);
}

.subtitle {
  font-size: 8px;
  color: var(--blue);
  margin-top: 12px;
  letter-spacing: 2px;
}

/* ---------- HOME: 5-button mode bar ---------- */
.mode-bar {
  display: flex;
  width: 100%;
  max-width: 640px;
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.mode-tab {
  font-family: 'Press Start 2P', monospace;
  font-size: 6px;
  background: var(--panel);
  color: var(--text-dim);
  border: none;
  border-right: 2px solid var(--border);
  padding: 10px 4px;
  cursor: pointer;
  flex: 1;
  text-align: center;
  letter-spacing: 0.5px;
  line-height: 2;
}

.mode-tab:last-child {
  border-right: none;
}

.mode-tab:hover:not(.active) {
  background: var(--border);
  color: var(--text);
}

.mode-tab.active {
  background: var(--yellow);
  color: #000;
}

.mode-tab:active {
  opacity: 0.85;
}

.mode-tab-sub {
  display: block;
  font-size: 5px;
  opacity: 0.8;
  margin-top: 3px;
  letter-spacing: 0;
}

/* ---------- HOME: Exercise grid ---------- */
.exercise-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  width: 100%;
  max-width: 640px;
}

.exercise-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 7px;
  background: var(--panel);
  color: var(--text);
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  padding: 16px 10px;
  cursor: pointer;
  text-align: left;
  line-height: 2;
  letter-spacing: 0.5px;
  transition: border-color 0.1s;
}

.exercise-btn:hover {
  border-color: var(--green);
  color: var(--green);
}

.exercise-btn:active {
  box-shadow: 2px 2px 0 #000;
  transform: translate(2px, 2px);
}

.exercise-btn .ex-num {
  color: var(--yellow);
  display: block;
  margin-bottom: 6px;
}

.exercise-btn .ex-icon {
  font-size: 16px;
  display: block;
  margin-bottom: 8px;
  line-height: 1;
}

/* Feedback check/X marks — sized to match CORRECT!/WRONG text */
.feedback-icon {
  font-size: 10px;
}

.home-footer {
  font-size: 8px;
  color: var(--text-dim);
  letter-spacing: 2px;
  animation: blink 1.2s step-end infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0; }
}

/* ---------- DRILL: Header ---------- */
.drill-header {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  max-width: 640px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
  position: relative;
}

.back-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 8px;
  background: transparent;
  color: var(--text-dim);
  border: 2px solid var(--text-dim);
  padding: 6px 10px;
  cursor: pointer;
  box-shadow: 2px 2px 0 #000;
  white-space: nowrap;
}

.back-btn:hover { color: var(--red); border-color: var(--red); }

.restart-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 8px;
  background: transparent;
  color: var(--text-dim);
  border: 2px solid var(--text-dim);
  padding: 6px 10px;
  cursor: pointer;
  box-shadow: 2px 2px 0 #000;
  white-space: nowrap;
}

.restart-btn:hover { color: var(--yellow); border-color: var(--yellow); }

.drill-title {
  flex: 1;
  text-align: center;
  font-size: 9px;
  color: var(--blue);
  letter-spacing: 1px;
}

#drill-difficulty {
  order: 1;
  font-size: 8px;
  line-height: 1;
  color: var(--text-dim);
  border: 2px solid var(--text-dim);
  padding: 6px 10px;
  box-shadow: 2px 2px 0 #000;
  white-space: nowrap;
}

.drill-timer {
  font-size: 11px;
  color: var(--yellow);
  min-width: 60px;
  text-align: right;
}

/* ---------- DRILL: Are you ready? screen ---------- */
.ready-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 32px 16px;
  text-align: center;
}

.ready-icon {
  font-size: 48px;
  line-height: 1;
}

.ready-name {
  font-size: 10px;
  color: var(--text);
  letter-spacing: 1px;
  line-height: 2;
}

.ready-hint {
  font-size: 7px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
  line-height: 2;
  max-width: 400px;
}

.ready-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 8px;
}

.diff-row {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-top: 12px;
  margin-bottom: 4px;
}

.diff-btn {
  font-family: inherit;
  font-size: 9px;
  letter-spacing: 0.08em;
  padding: 6px 14px;
  border: 2px solid var(--green);
  background: transparent;
  color: var(--green);
  cursor: pointer;
  text-transform: uppercase;
}

.diff-btn.active {
  background: var(--green);
  color: var(--bg);
}

.diff-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.drill-timer.warning { color: var(--red); }

/* ---------- DRILL: Body ---------- */
.drill-body {
  width: 100%;
  max-width: 640px;
  flex: 1;
}

#drill-area {
  width: 100%;
}

/* ---------- Drill cards (used by exercise modules) ---------- */
.drill-card {
  position: relative;
  background: var(--panel);
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  padding: 24px 20px;
  margin-bottom: 16px;
}

.drill-timer-q {
  font-size: 8px;
  color: var(--yellow);
}

.drill-timer-q.warning { color: var(--red); }

.drill-question {
  font-size: 11px;
  color: var(--text);
  margin-bottom: 20px;
  line-height: 2.2;
}

.drill-question .highlight {
  color: var(--yellow);
}

.drill-input-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  flex-wrap: wrap;
}

.drill-input-label {
  font-size: 8px;
  color: var(--blue);
  min-width: 80px;
}

.drill-input {
  font-family: 'Press Start 2P', monospace;
  font-size: 10px;
  background: #000;
  color: var(--green);
  border: 2px solid var(--border);
  box-shadow: inset 2px 2px 0 #000;
  padding: 8px 12px;
  width: 200px;
  outline: none;
}

.drill-input:focus {
  border-color: var(--green);
}

.drill-input::placeholder {
  color: var(--text-dim);
  font-size: 8px;
}

.input-submitted {
  color: var(--text-dim) !important;
  background: #111 !important;
  border-color: var(--text-dim) !important;
}

/* ---------- Buttons ---------- */
.btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 9px;
  border: 2px solid;
  box-shadow: var(--shadow);
  padding: 12px 20px;
  cursor: pointer;
  letter-spacing: 1px;
}

.btn:active {
  box-shadow: 2px 2px 0 #000;
  transform: translate(2px, 2px);
}

.btn-primary {
  background: var(--green);
  color: #000;
  border-color: #1a7a00;
}

.btn-primary:hover { background: #60ff40; }

.btn-secondary {
  background: var(--panel);
  color: var(--blue);
  border-color: var(--blue);
}

.btn-secondary:hover { background: var(--blue); color: #000; }

.btn-danger {
  background: var(--panel);
  color: var(--red);
  border-color: var(--red);
}

.btn-danger:hover { background: var(--red); color: #000; }

.btn-submitted {
  background: #333 !important;
  color: var(--text-dim) !important;
  border-color: var(--text-dim) !important;
  cursor: default !important;
  pointer-events: none;
}

.btn-self-grade {
  font-size: 20px;
  padding: 10px 20px;
  background: var(--panel);
  border-color: var(--border);
}

.btn-self-grade:hover { border-color: var(--yellow); }

/* ---------- Feedback overlays ---------- */
.feedback-box {
  padding: 16px;
  margin-top: 12px;
  font-size: 10px;
  text-align: center;
  border: 2px solid;
  box-shadow: var(--shadow);
}

.feedback-correct {
  background: #001a00;
  border-color: var(--green);
  color: var(--green);
  animation: flash-correct 0.4s ease;
}

.feedback-wrong {
  background: #1a0005;
  border-color: var(--red);
  color: var(--red);
  animation: flash-wrong 0.4s ease;
}

.feedback-neutral {
  background: var(--panel);
  border-color: var(--blue);
  color: var(--blue);
}

@keyframes flash-correct {
  0%   { background: var(--green); color: #000; }
  100% { background: #001a00; color: var(--green); }
}

@keyframes flash-wrong {
  0%   { background: var(--red); color: #000; }
  100% { background: #1a0005; color: var(--red); }
}

/* ---------- Progress indicators ---------- */
.drill-progress {
  font-size: 8px;
  color: var(--text-dim);
}

.progress-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}

.drill-progress .current { color: var(--yellow); }

.time-goal {
  font-size: 8px;
  color: var(--text-dim);
  margin-bottom: 16px;
}

.time-goal .goal-num { color: var(--blue); }

/* ---------- Countdown (ex08) ---------- */
.countdown-bar {
  width: 100%;
  height: 12px;
  background: #000;
  border: 2px solid var(--border);
  margin-bottom: 16px;
  overflow: hidden;
}

.countdown-fill {
  height: 100%;
  background: var(--green);
  transition: width 1s linear, background 0.5s;
}

.countdown-fill.low { background: var(--red); }

/* ---------- SUMMARY screen ---------- */
.summary-header {
  text-align: center;
  padding: 16px 0;
}

.summary-drill-name {
  font-size: 7px;
  color: var(--blue);
  letter-spacing: 2px;
  margin-bottom: 10px;
}

.summary-title {
  font-size: 18px;
  color: var(--yellow);
  text-shadow: 3px 3px 0 #7a6000;
}

.summary-stats {
  background: var(--panel);
  border: 2px solid var(--border);
  box-shadow: var(--shadow);
  padding: 24px;
  width: 100%;
  max-width: 500px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
}

.stat-row:last-child { border-bottom: none; padding-bottom: 0; }

.stat-label {
  font-size: 8px;
  color: var(--text-dim);
}

.stat-value {
  font-size: 11px;
  color: var(--green);
}

.stat-value.accent { color: var(--yellow); }

.summary-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

/* ---------- Utility classes ---------- */
.text-green  { color: var(--green); }
.text-yellow { color: var(--yellow); }
.text-red    { color: var(--red); }
.text-blue   { color: var(--blue); }
.text-dim    { color: var(--text-dim); }

.mt-8  { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }

.flex-row { display: flex; flex-direction: row; gap: 12px; align-items: center; }
.flex-col { display: flex; flex-direction: column; gap: 12px; }
.flex-center { justify-content: center; align-items: center; }

/* ---------- Triangle layout — ex04 ---------- */
.tri-layout { margin: 16px 0 8px; }
.tri-row-top { text-align: center; margin-bottom: 12px; }
.tri-row-bottom { display: flex; justify-content: space-between; gap: 12px; }
.tri-node {
  background: var(--panel);
  border: 1px solid var(--border);
  box-shadow: 2px 2px 0 var(--border);
  padding: 10px 14px;
  min-width: 90px;
  font-size: 9px;
  text-align: center;
  display: inline-block;
}
.tri-node-label { color: var(--text-dim); margin-bottom: 4px; letter-spacing: 1px; }
.tri-node-value { color: var(--green); font-size: 11px; font-weight: bold; }
.tri-node-blank { border-color: var(--yellow); }
.tri-node-blank .tri-node-label { color: var(--yellow); }
.tri-node-blank .drill-input { width: 100%; margin-top: 4px; font-size: 9px; box-sizing: border-box; }

/* ---------- DIFFICULTY EXPLAINED screen ---------- */
.diff-exp-header {
  display: flex;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 640px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border);
  position: relative;
}

.diff-exp-title {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  font-size: 11px;
  color: var(--yellow);
  letter-spacing: 1px;
  white-space: nowrap;
}

.diff-exp-body {
  width: 100%;
  max-width: 640px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.diff-exp-intro {
  font-size: 10px;
  color: var(--text);
  line-height: 2.2;
  letter-spacing: 0.5px;
  background: #0d1520;
  padding: 10px 14px;
  border: 2px solid var(--border);
}

.diff-exp-section-label {
  font-size: 11px;
  color: var(--blue);
  letter-spacing: 1px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px;
}

.diff-exp-table-wrap {
  overflow-x: auto;
}

.diff-exp-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 10px;
  line-height: 1.8;
}

.diff-exp-table th,
.diff-exp-table td {
  border: 2px solid var(--border);
  padding: 10px 14px;
  text-align: center;
  vertical-align: middle;
}

.diff-exp-table thead th {
  background: var(--panel);
  letter-spacing: 0.5px;
}

.diff-exp-table tbody td {
  background: #0d1520;
}

.diff-exp-table .col-val {
  color: var(--text);
  text-align: left;
  font-size: 11px;
  font-weight: bold;
  letter-spacing: 0.5px;
  white-space: nowrap;
  width: 1%;
}

.col-tol {
  color: var(--text);
  font-size: 9px;
}

.col-val-head {
  color: var(--text);
  white-space: nowrap;
  width: 1%;
}

.col-example-head {
  width: auto;
}

.col-example {
  font-size: 11px;
  line-height: 1.8;
}

.ex-label {
  font-size: 9px;
  color: var(--text);
  display: block;
}

/* Difficulty toggle tabs in table header */
.diff-toggle {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.diff-tab {
  font-family: inherit;
  font-size: 10px;
  letter-spacing: 0.5px;
  padding: 4px 8px;
  background: transparent;
  border: none;
  color: var(--text-dim);
  cursor: pointer;
  line-height: 1.6;
  transition: color 0.1s;
}

.diff-tab[data-diff="easy"].active  { color: var(--green); }
.diff-tab[data-diff="med"].active   { color: var(--yellow); }
.diff-tab[data-diff="hard"].active  { color: var(--red); }

.diff-exp-table .col-easy { color: var(--green); }
.diff-exp-table .col-med  { color: var(--yellow); }
.diff-exp-table .col-hard { color: var(--red); }

.diff-exp-note {
  font-size: 10px;
  color: var(--text);
  line-height: 2.2;
  letter-spacing: 0.5px;
  background: #0d1520;
  padding: 10px 14px;
  border: 2px solid var(--border);
}

/* ---------- Restart modal ---------- */
#modal-overlay {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
}

.modal-box {
  background: var(--panel);
  border: 2px solid var(--yellow);
  box-shadow: 4px 4px 0 #7a6000, 8px 8px 0 #000;
  padding: 32px 24px;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 24px;
  min-width: 220px;
}

.modal-msg {
  font-size: 11px;
  color: var(--yellow);
  letter-spacing: 2px;
  line-height: 2;
}

.modal-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
}

/* ---------- Numpad ---------- */

/* Toggle button — sits inside .flex-row alongside SUBMIT and PASS */
.numpad-toggle-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 9px;
  padding: 12px 16px;
  background: transparent;
  color: var(--purple);
  border: 2px solid var(--purple);
  cursor: pointer;
  letter-spacing: 1px;
}

.numpad-toggle-btn.active {
  background: var(--blue);
  color: #000;
  border-color: var(--blue);
}

.numpad-toggle-btn:active {
  transform: translate(2px, 2px);
}

.sound-toggle-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 9px;
  padding: 12px 16px;
  background: transparent;
  color: var(--green);
  border: 2px solid var(--green);
  cursor: pointer;
  letter-spacing: 1px;
}

.sound-toggle-btn.muted {
  color: var(--text-dim);
  border-color: var(--text-dim);
}

.sound-toggle-btn:active {
  transform: translate(2px, 2px);
}

/* Panel — sits below #drill-area inside .drill-body */
#numpad-panel {
  width: 100%;
  max-width: 640px;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
  padding: 12px;
  margin-top: 0;
  background: var(--panel);
  border: 2px solid var(--border);
  border-top: none;
}

.np-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 9px;
  padding: 14px 0;
  background: transparent;
  color: var(--border);
  border: 2px solid var(--border);
  cursor: pointer;
  text-align: center;
  letter-spacing: 0;
}

.np-btn:active {
  background: var(--border);
  color: #000;
}

.np-num {
  color: var(--yellow);
}


.np-wide {
  grid-column: span 2;
}

/* iOS Safari zoom fix: prevent zoom-on-focus when numpad is active.
   font-size >=16px tells iOS not to zoom the viewport. */
.numpad-mode .drill-input {
  font-size: 16px !important;
}

/* ── Dim button variant ── */
.btn-dim {
  background: var(--panel);
  color: var(--text-dim);
  border-color: var(--text-dim);
}

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

/* ── Splash Screen ── */
#screen-splash {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
}

.splash-stage {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.splash-word {
  font-family: 'Press Start 2P', monospace;
  font-size: 48px;
  color: var(--yellow);
  letter-spacing: 4px;
  opacity: 0;
  transform: translateY(-60px);
  transition: opacity 0.33s ease, transform 0.39s ease;
}

.splash-word.landed {
  opacity: 1;
  transform: translateY(0);
}

#screen-splash.fading {
  opacity: 0;
  transition: opacity 0.52s ease;
}

/* ── Log-In Entry Screen ── */
#screen-login-entry {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
}

.login-entry-logo {
  font-family: 'Press Start 2P', monospace;
  font-size: 28px;
  color: var(--yellow);
  letter-spacing: 4px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.login-entry-tagline {
  font-family: 'Press Start 2P', monospace;
  font-size: 8px;
  color: var(--text-dim);
  letter-spacing: 2px;
}

.login-entry-buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 280px;
}

/* ── Contact Creator ── */
.contact-row {
  text-align: center;
  margin-top: 16px;
  padding-bottom: 12px;
}

.contact-btn {
  font-family: 'Press Start 2P', monospace;
  font-size: 7px;
  color: var(--text-dim);
  letter-spacing: 1px;
  text-decoration: none;
  border: 1px solid var(--text-dim);
  padding: 6px 12px;
}

.contact-btn:hover,
.contact-btn:active {
  color: var(--text);
  border-color: var(--text);
}

/* ---------- Responsive ---------- */
@media (max-width: 480px) {
  .exercise-grid { grid-template-columns: 1fr; }
  .title { font-size: 22px; }
  .drill-input { width: 160px; font-size: 16px; }
}