/* Design tokens */
:root {
  --color-bg: #f7f5f0;
  --color-text: #14181c;
  --color-primary: #16324a;
  --color-primary-contrast: #ffffff;
  --color-border: #cfc9bc;
  --color-surface: #ffffff;
  --color-error: #b3261e;
  --focus-ring: 4px solid #0b5fff;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;

  --font-size-body: 28px;
  --font-size-large: 34px;
  --font-size-title: 44px;

  --touch-min: 88px;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, "SF Pro Text", system-ui, sans-serif;
  font-size: var(--font-size-body);
  line-height: 1.4;
  -webkit-tap-highlight-color: transparent;
}

button {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

button:focus-visible,
a:focus-visible {
  outline: var(--focus-ring);
  outline-offset: 3px;
}

[hidden] {
  display: none !important;
}

/* Generic screen container */
.screen {
  min-height: 100vh;
  padding: var(--space-3);
}

/* ---------- Login gate ---------- */
.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-3);
}

.login-card {
  width: 100%;
  max-width: 420px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-3);
  border-radius: 24px;
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.12);
}

.login-lock-icon {
  width: 56px;
  height: 56px;
  color: var(--color-primary);
}

.login-title {
  font-size: var(--font-size-title);
  font-weight: 700;
  margin: 0;
  text-align: center;
}

.login-label {
  font-size: var(--font-size-large);
  font-weight: 700;
  text-align: center;
}

.pin-boxes-wrap {
  position: relative;
  width: 100%;
}

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

.pin-box {
  width: 52px;
  height: 64px;
  border-radius: 12px;
  border: 2px solid var(--color-border);
  background: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  font-weight: 700;
}

.pin-box.filled {
  border-color: var(--color-primary);
}

.pin-input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  border: 0;
  padding: 0;
  margin: 0;
}

.login-submit {
  min-width: 100%;
  font-size: var(--font-size-large);
}

.login-error {
  color: var(--color-error);
  font-size: 22px;
  font-weight: 700;
  text-align: center;
  margin: 0;
}

.login-card.shake {
  animation: login-shake 0.4s;
}

@keyframes login-shake {
  10%, 90% { transform: translateX(-6px); }
  20%, 80% { transform: translateX(10px); }
  30%, 50%, 70% { transform: translateX(-14px); }
  40%, 60% { transform: translateX(14px); }
}

/* ---------- Library screen ---------- */
.app-header {
  font-size: var(--font-size-title);
  font-weight: 700;
  margin: 0 0 var(--space-3) 0;
}

.btn-refresh {
  display: block;
  width: 100%;
  min-height: var(--touch-min);
  margin-bottom: var(--space-3);
  border-radius: 16px;
  border: 2px solid var(--color-primary);
  background: var(--color-surface);
  color: var(--color-primary);
  font-size: var(--font-size-body);
  font-weight: 700;
}

.btn-refresh:disabled {
  opacity: 0.6;
}

.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-3);
  list-style: none;
  padding: 0;
  margin: 0;
}

.book-tile {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  min-height: 180px;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: 16px;
  padding: var(--space-2);
  text-align: left;
  cursor: pointer;
}

.book-tile img {
  width: 140px;
  height: 140px;
  object-fit: cover;
  border-radius: 10px;
  background: var(--color-border);
  flex-shrink: 0;
}

.book-tile-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  min-width: 0;
}

.book-tile-title {
  font-size: var(--font-size-large);
  font-weight: 700;
  overflow-wrap: break-word;
}

.book-tile-author {
  font-size: var(--font-size-body);
  color: var(--color-text);
}

.book-tile-progress {
  font-size: 22px;
  color: var(--color-primary);
  font-weight: 600;
}

.empty-state {
  font-size: var(--font-size-large);
}

/* ---------- Player screen ---------- */
.player-topbar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.btn-back {
  min-height: var(--touch-min);
  min-width: var(--touch-min);
  border: 2px solid var(--color-border);
  border-radius: 14px;
  background: var(--color-surface);
  font-size: var(--font-size-body);
  font-weight: 700;
  padding: 0 var(--space-2);
}

.player-cover {
  display: block;
  width: 260px;
  height: 260px;
  max-width: 60vw;
  max-height: 60vw;
  object-fit: cover;
  border-radius: 16px;
  margin: 0 auto var(--space-3) auto;
  background: var(--color-border);
}

.player-book-title {
  font-size: var(--font-size-title);
  font-weight: 700;
  text-align: center;
  margin: 0 0 var(--space-1) 0;
}

.player-chapter-title {
  font-size: var(--font-size-large);
  text-align: center;
  margin: 0 0 var(--space-3) 0;
  color: var(--color-primary);
}

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

.progress-bar {
  flex: 1;
  height: 20px;
  background: var(--color-border);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--color-primary);
  width: 0%;
}

.progress-time {
  font-size: 22px;
  font-variant-numeric: tabular-nums;
  min-width: 4.5em;
  text-align: center;
}

.transport-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.btn-skip {
  min-width: var(--touch-min);
  min-height: var(--touch-min);
  border-radius: 20px;
  border: 2px solid var(--color-primary);
  background: var(--color-surface);
  color: var(--color-primary);
  font-weight: 700;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-1);
  gap: 4px;
}

.btn-skip .icon {
  font-size: 34px;
  line-height: 1;
}

.btn-skip .label {
  font-size: 18px;
}

.btn-play-pause {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  border: none;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  font-size: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chapter-nav-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.btn-chapter {
  min-height: var(--touch-min);
  min-width: 260px;
  border-radius: 16px;
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  font-size: 24px;
  font-weight: 600;
  padding: var(--space-1) var(--space-2);
}

.btn-chapter:disabled {
  opacity: 0.4;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f1113;
    --color-text: #f2efe9;
    --color-surface: #1c1f22;
    --color-border: #3a3f44;
    --color-primary: #6fa8dc;
    --color-primary-contrast: #0f1113;
    --color-error: #ff8a80;
  }
}