/* AcidBase Mastery — Components */

/* Cards */
.card {
  padding: 2.5rem 2rem;
  background: var(--surface);
  border: 1px solid var(--surface-border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--teal), var(--accent));
  transform: scaleX(0) translateZ(0);
  transform-origin: left center;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  will-change: transform;
  backface-visibility: hidden;
}

.card:hover::before {
  transform: scaleX(1) translateZ(0);
}

.card:hover,
.card:focus-within {
  background: var(--surface-hover);
  transform: translateY(-4px);
}

.card-number {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  color: var(--text-dim);
  margin-bottom: 1.5rem;
}

.card-title {
  font-size: 1.4rem;
  font-weight: 500;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.card-desc {
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--text);
  opacity: 0.6;
  margin-bottom: 1.5rem;
}

/* Buttons */
.btn {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.8rem 1.6rem;
  border: 1px solid var(--surface-border);
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn:hover {
  background: var(--teal);
  border-color: var(--teal);
  color: var(--bg);
}

.btn-primary {
  background: var(--teal);
  border-color: var(--teal);
  color: var(--bg);
}

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

.btn-accent {
  border-color: rgba(196, 163, 90, 0.3);
  background: rgba(196, 163, 90, 0.05);
}

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

.btn:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 2px;
  background: var(--teal);
  border-color: var(--teal);
  color: var(--bg);
}

.btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

/* Input fields */
.input {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  padding: 0.8rem 1rem;
  border: 1px solid var(--surface-border);
  background: rgba(13, 12, 10, 0.5);
  color: var(--text);
  outline: none;
  transition: border-color 0.3s ease;
  width: 100%;
}

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

.input::placeholder {
  color: var(--text-dim);
}

/* Badges */
.badge {
  font-family: var(--font-mono);
  font-size: 0.55rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.6rem;
  border: 1px solid;
  display: inline-block;
}

.badge-novice {
  border-color: rgba(255, 255, 255, 0.1);
  color: var(--text-dim);
}

.badge-developing {
  border-color: rgba(184, 122, 106, 0.3);
  color: var(--coral);
}

.badge-proficient {
  border-color: rgba(90, 138, 135, 0.3);
  color: var(--teal);
}

.badge-mastered {
  border-color: rgba(196, 163, 90, 0.3);
  color: var(--accent);
}

/* Loading spinner */
.spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--surface-border);
  border-top-color: var(--teal);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 4rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}

/* Grid helpers */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

@media (max-width: 900px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }
}

/* Toast notifications */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  padding: 1rem 1.5rem;
  background: rgba(13, 12, 10, 0.95);
  border: 1px solid var(--surface-border);
  backdrop-filter: blur(12px);
  color: var(--text);
  transform: translateX(120%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast.show {
  transform: translateX(0);
}

.toast-success {
  border-color: rgba(90, 138, 106, 0.3);
}

.toast-error {
  border-color: rgba(184, 122, 106, 0.3);
}

/* Page subtitle */
.page-subtitle {
  color: var(--text-dim);
  margin-top: 1rem;
  margin-bottom: 4rem;
  max-width: 600px;
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Chapter groups */
.chapter-group {
  margin-bottom: 4rem;
}

.chapter-heading {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--teal);
  margin-bottom: 2rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--surface-border);
}

/* Topic list */
.topic-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.topic-card .card-title {
  font-size: 1.1rem;
}

.topic-card .card-desc {
  font-size: 0.8rem;
  margin-bottom: 0.75rem;
}

/* Topic page content */
.topic-content {
  margin-bottom: 3rem;
  max-width: 800px;
}

.topic-section-heading {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.5rem;
}

/* Key points list */
.key-points {
  list-style: none;
  padding: 0;
}

.key-points li {
  position: relative;
  padding: 0.75rem 0 0.75rem 1.5rem;
  font-size: 0.9rem;
  line-height: 1.7;
  color: var(--text);
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.key-points li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  background: var(--teal);
  border-radius: 50%;
}

.key-points li strong {
  color: var(--text-bright);
}

/* Formula cards */
.formula-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}

.formula-card {
  padding: 1.25rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--surface-border);
}

.formula-label {
  font-family: var(--font-mono);
  font-size: 0.55rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

.formula-expr {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-bright);
  letter-spacing: 0.02em;
}

/* Visualization placeholder */
.viz-placeholder {
  margin: 2rem 0 3rem;
  padding: 3rem 2rem;
  background: var(--surface);
  border: 1px dashed var(--surface-border);
  text-align: center;
}

.viz-placeholder-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Topic navigation */
.topic-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--surface-border);
}

.topic-nav .btn {
  font-size: 0.6rem;
  max-width: 45%;
  text-align: center;
  text-decoration: none;
}

/* Reference tables */
.ref-table-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.ref-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.ref-table thead th {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--teal);
  text-align: left;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--surface-border);
  position: sticky;
  top: 0;
  background: var(--bg);
}

.ref-table tbody td {
  padding: 0.6rem 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
  color: var(--text);
}

.ref-table tbody tr:hover td {
  background: rgba(90, 138, 135, 0.03);
}

.formula-cell {
  font-weight: 500;
  color: var(--text-bright);
}

.num-cell {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text);
  white-space: nowrap;
}

@media (max-width: 600px) {
  .topic-list {
    grid-template-columns: 1fr;
  }

  .formula-list {
    grid-template-columns: 1fr;
  }

  .topic-nav {
    flex-direction: column;
  }

  .topic-nav .btn {
    max-width: 100%;
  }

  .ref-table {
    font-size: 0.7rem;
  }

  .ref-table thead th,
  .ref-table tbody td {
    padding: 0.5rem 0.6rem;
  }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
  .btn {
    padding: 1rem 1.8rem;
    font-size: 0.7rem;
  }

  .card:hover {
    transform: none;
    background: var(--surface);
  }

  .card:active {
    background: var(--surface-hover);
  }

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

  .btn:active {
    background: var(--teal);
    border-color: var(--teal);
    color: var(--bg);
  }
}