/* ============================================
   Apple Platform Expansion Guide - Styles
   ============================================ */

:root {
  --color-bg: #FAFAFA;
  --color-text: #1D1D1F;
  --color-text-secondary: #6E6E73;
  --color-text-muted: #86868B;
  --color-text-dim: #A1A1A6;
  --color-surface: #ffffff;
  --color-border: #E5E5EA;
  --color-border-light: #F0F0F0;
  --color-bg-subtle: #F5F5F7;
  --color-green: #34C759;
  --color-red: #FF3B30;
  --color-orange: #FF9500;
  --color-macos: #0071E3;
  --color-watchos: #FF375F;
  --color-ipados: #5856D6;
  --color-tvos: #64D2FF;
  --color-visionos: #AC8E68;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 1px 4px rgba(0,0,0,0.06);
  --font-family: 'SF Pro Display', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-family);
  background: var(--color-bg);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Animations */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-8px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes barGrow {
  from { width: 0; }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.animate-fade-up {
  animation: fadeInUp 0.4s ease-out forwards;
}

.animate-slide-in {
  animation: slideIn 0.3s ease-out forwards;
}

/* Header */
.header {
  background: linear-gradient(135deg, #1D1D1F 0%, #2D2D2F 50%, #1D1D1F 100%);
  padding: 40px 24px 30px;
  color: white;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 30% 50%, rgba(0,113,227,0.06) 0%, transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(88,86,214,0.06) 0%, transparent 50%);
  pointer-events: none;
}

.header__label {
  font-size: 12px;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 8px;
  font-weight: 500;
  position: relative;
}

.header__title {
  font-size: 30px;
  font-weight: 700;
  margin: 0 0 8px;
  letter-spacing: -0.5px;
  line-height: 1.2;
  position: relative;
}

.header__subtitle {
  font-size: 14px;
  color: var(--color-text-dim);
  font-weight: 400;
  position: relative;
}

/* Section Labels */
.section-label {
  font-size: 11px;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 14px;
  font-weight: 600;
}

/* Platform Selector */
.platform-section {
  padding: 20px 20px 0;
}

.platform-tabs {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.platform-tabs::-webkit-scrollbar {
  display: none;
}

.platform-tab {
  flex: 0 0 auto;
  padding: 12px 18px;
  border: 2px solid transparent;
  border-radius: var(--radius-md);
  background: var(--color-surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.25s ease;
  box-shadow: var(--shadow-sm);
  font-family: inherit;
}

.platform-tab:hover {
  transform: translateY(-1px);
  box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}

.platform-tab--active {
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.platform-tab__icon {
  font-size: 20px;
}

.platform-tab__title {
  font-size: 14px;
  font-weight: 600;
}

.platform-tab__subtitle {
  font-size: 9px;
  color: var(--color-text-muted);
}

/* ============================================
   Chapter Navigation
   ============================================ */

.page-section {
  padding: 0 20px;
}

.chapter-nav {
  display: flex;
  gap: 2px;
  margin: 18px 0 0;
  border-bottom: 1px solid var(--color-border-light);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.chapter-nav::-webkit-scrollbar {
  display: none;
}

.chapter-nav__item {
  flex: 0 0 auto;
  padding: 12px 16px;
  border: none;
  border-bottom: 2px solid transparent;
  background: none;
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: inherit;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.chapter-nav__item:hover {
  color: var(--color-text-secondary);
}

.chapter-nav__item--active {
  font-weight: 600;
  border-bottom-width: 2px;
  border-bottom-style: solid;
}

.chapter-nav__icon {
  font-size: 15px;
}

.chapter-nav__label {
  font-size: 13px;
}

/* Chapter Content */
.page-content {
  padding: 20px 0 28px;
}

.chapter-content {
  min-height: 200px;
}

.chapter-section-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.chapter-section-desc {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-bottom: 18px;
  line-height: 1.5;
}

/* ============================================
   Overview Chapter
   ============================================ */

.overview-hero {
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  border: 1px solid;
  margin-bottom: 18px;
}

.overview-hero__icon {
  font-size: 48px;
  margin-bottom: 10px;
}

.overview-hero__title {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.overview-hero__desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.overview-info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 18px;
}

.overview-info-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  box-shadow: var(--shadow-sm);
}

.overview-info-card__label {
  font-size: 10px;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.overview-info-card__value {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

/* Decision Flow (inline in iOS overview) */
.decision-flow-inline {
  margin-top: 4px;
}

.flow-steps {
  display: flex;
  gap: 2px;
  align-items: stretch;
}

.flow-step {
  flex: 1;
  background: var(--color-surface);
  padding: 16px 10px;
  text-align: center;
  position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.flow-step:first-child {
  border-radius: var(--radius-md) 0 0 var(--radius-md);
}

.flow-step:last-child {
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.flow-step:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  z-index: 1;
}

.flow-step__icon {
  font-size: 22px;
  margin-bottom: 8px;
}

.flow-step__title {
  font-size: 10px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 4px;
  line-height: 1.3;
}

.flow-step__desc {
  font-size: 9px;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.flow-step__arrow {
  position: absolute;
  right: -7px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  font-size: 12px;
  color: var(--color-text-muted);
}

/* Key Question Card */
.key-question {
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  margin-bottom: 18px;
  transition: all 0.3s ease;
}

.key-question__label {
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.key-question__text {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.4;
}

.key-question__meta {
  display: flex;
  gap: 16px;
  margin-top: 14px;
  flex-wrap: wrap;
  align-items: center;
}

.badge {
  font-size: 10px;
  padding: 4px 10px;
  border-radius: 6px;
  font-weight: 600;
}

.meta-info {
  font-size: 12px;
  color: var(--color-text-muted);
}

/* ============================================
   Criteria Chapter
   ============================================ */

.criteria-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.criteria-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease;
}

.criteria-card:hover {
  transform: translateX(4px);
}

.criteria-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.criteria-card__label-group {
  display: flex;
  align-items: center;
  gap: 10px;
}

.criteria-card__icon {
  font-size: 20px;
}

.criteria-card__name {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
}

.criteria-card__weight {
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 6px;
}

.criteria-card__desc {
  font-size: 12px;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 10px;
  padding-left: 30px;
}

.criteria-card__bar-track {
  height: 4px;
  background: var(--color-border-light);
  border-radius: 2px;
  overflow: hidden;
  margin-left: 30px;
}

.criteria-card__bar-fill {
  height: 100%;
  border-radius: 2px;
  animation: barGrow 0.8s ease-out forwards;
}

/* Fit Section */
.fit-section {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.fit-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 18px;
  box-shadow: var(--shadow-sm);
}

.fit-card__header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
}

.fit-card__icon {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
}

.fit-card__title {
  font-size: 15px;
  font-weight: 600;
}

.fit-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.fit-tag {
  font-size: 12px;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-weight: 500;
}

.fit-tag--good {
  background: rgba(52, 199, 89, 0.06);
  color: #1D7A34;
  border: 1px solid rgba(52, 199, 89, 0.12);
}

.fit-tag--bad {
  background: rgba(255, 59, 48, 0.03);
  color: #CC2D25;
  border: 1px solid rgba(255, 59, 48, 0.08);
}

/* Checklist */
.checklist {
  border-radius: var(--radius-md);
  padding: 18px;
  border: 1px solid var(--color-border);
}

.checklist__title {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.checklist__item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 0;
}

.checklist__item:not(:last-child) {
  border-bottom: 1px solid var(--color-border-light);
}

.checklist__item-icon {
  font-size: 16px;
}

.checklist__item-label {
  font-size: 13px;
  color: var(--color-text);
  flex: 1;
}

.checklist__item-badge {
  font-size: 11px;
  color: var(--color-text-muted);
}

.checklist__hint {
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 12px;
  line-height: 1.5;
}

/* ============================================
   Expansion Directions Chapter
   ============================================ */

.expansion-targets {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.expansion-target {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.expansion-target__header {
  width: 100%;
  padding: 14px 16px;
  background: var(--color-surface);
  border: none;
  border-left: 3px solid;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-family: inherit;
  transition: background 0.15s ease;
}

.expansion-target__header:hover {
  background: #FAFAFA;
}

.expansion-target__header--active {
  background: #FAFAFA;
}

.expansion-target__left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.expansion-target__icons {
  font-size: 20px;
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.expansion-target__arrow-icon {
  font-size: 14px;
  color: var(--color-text-muted);
}

.expansion-target__title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  text-align: left;
}

.expansion-target__approach {
  font-size: 11px;
  color: var(--color-text-muted);
  text-align: left;
}

.expansion-target__right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.expansion-target__chevron {
  font-size: 12px;
  color: var(--color-text-muted);
}

.expansion-detail {
  padding: 16px 18px 18px;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border-light);
}

.expansion-detail__subtitle {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.expansion-detail__changes {
  margin-bottom: 16px;
}

.expansion-detail__change {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 0;
  font-size: 13px;
  color: var(--color-text);
  line-height: 1.4;
}

.expansion-detail__change:not(:last-child) {
  border-bottom: 1px solid var(--color-border-light);
}

.expansion-detail__change-bullet {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}

.expansion-detail__consideration {
  margin-bottom: 16px;
}

.expansion-detail__consideration p {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.expansion-detail__meta {
  margin-bottom: 16px;
}

.expansion-detail__effort {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--color-bg-subtle);
  border-radius: var(--radius-sm);
}

.expansion-detail__effort-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-secondary);
}

.expansion-detail__effort-dots {
  font-size: 14px;
  letter-spacing: 2px;
}

.expansion-detail__effort-num {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-left: auto;
}

.expansion-detail__example {
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid;
}

.expansion-detail__example p {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ============================================
   Examples Chapter
   ============================================ */

.example-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.example-card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 18px;
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  gap: 16px;
  transition: transform 0.2s ease;
}

.example-card:hover {
  transform: translateX(4px);
}

.example-card__icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}

.example-card__name {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 4px;
}

.example-card__reason {
  font-size: 12px;
  color: var(--color-text-secondary);
  line-height: 1.4;
}

.strategy-hint {
  background: var(--color-bg-subtle);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  margin-top: 14px;
}

.strategy-hint__title {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.strategy-hint__text {
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ============================================
   Comparison Matrix Chapter
   ============================================ */

.matrix {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.matrix__header {
  display: grid;
  grid-template-columns: 1fr repeat(5, 54px);
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  padding: 12px 16px;
  background: #FAFAFA;
  border-bottom: 1px solid var(--color-border-light);
  text-align: center;
}

.matrix__header-label {
  text-align: left;
}

.matrix__row {
  display: grid;
  grid-template-columns: 1fr repeat(5, 54px);
  padding: 11px 16px;
  font-size: 12px;
  text-align: center;
  align-items: center;
  transition: background 0.15s ease;
}

.matrix__row:hover {
  background: #FAFAFA;
}

.matrix__row:not(:last-child) {
  border-bottom: 1px solid var(--color-bg-subtle);
}

.matrix__factor {
  text-align: left;
  font-weight: 500;
  color: var(--color-text);
  font-size: 12px;
}

.matrix__cell {
  font-size: 15px;
}

.matrix__legend {
  padding: 10px 16px;
  background: #FAFAFA;
  display: flex;
  gap: 20px;
  font-size: 11px;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border-light);
}

/* ============================================
   Priority Framework Chapter
   ============================================ */

.priority-card {
  background: linear-gradient(135deg, #1D1D1F, #2D2D2F);
  border-radius: var(--radius-lg);
  padding: 24px;
  color: white;
}

.priority-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.priority-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 14px;
  background: rgba(255,255,255,0.05);
  border-radius: 10px;
  border-left: 3px solid;
  transition: background 0.2s ease, transform 0.2s ease;
}

.priority-item:hover {
  background: rgba(255,255,255,0.08);
  transform: translateX(4px);
}

.priority-item__number {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}

.priority-item__title {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 3px;
}

.priority-item__desc {
  font-size: 12px;
  color: var(--color-text-dim);
}

.priority-item__tag {
  font-size: 9px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 6px;
  white-space: nowrap;
}

.priority-footer {
  margin-top: 18px;
  padding: 14px;
  background: rgba(255,255,255,0.06);
  border-radius: 10px;
  font-size: 12px;
  color: var(--color-text-dim);
  line-height: 1.6;
}

.priority-footer strong {
  color: #F5F5F7;
}

/* Footer */
.footer {
  text-align: center;
  padding: 20px 20px 32px;
  font-size: 11px;
  color: var(--color-text-muted);
}

.footer a {
  color: var(--color-macos);
  text-decoration: none;
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 600px) {
  .header { padding: 32px 16px 24px; }
  .header__title { font-size: 24px; }
  .flow-steps { overflow-x: auto; }
  .flow-step { min-width: 100px; }
  .matrix__header,
  .matrix__row { grid-template-columns: 1fr repeat(5, 44px); font-size: 10px; }
  .matrix__cell { font-size: 13px; }
  .chapter-nav__item { padding: 10px 12px; }
  .chapter-nav__label { font-size: 12px; }
  .overview-hero { padding: 22px 18px; }
  .overview-hero__icon { font-size: 40px; }
  .overview-hero__title { font-size: 20px; }
}

@media (min-width: 768px) {
  .header__title { font-size: 34px; }
  .page-section { max-width: 720px; margin-left: auto; margin-right: auto; }
  .platform-section { max-width: 720px; margin-left: auto; margin-right: auto; }
}

/* ============================================
   Floating Donate Button
   ============================================ */

.donate-fab {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #FEE500, #F5C800);
  border: none;
  cursor: pointer;
  font-size: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.18);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  z-index: 1000;
  animation: fabBounce 2s ease-in-out infinite;
}

.donate-fab:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 24px rgba(0,0,0,0.25);
  animation: none;
}

@keyframes fabBounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Donate Modal Overlay */
.donate-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1001;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.2s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.donate-modal {
  background: #F0F1F5;
  border-radius: 20px;
  padding: 32px 28px;
  max-width: 320px;
  width: 90%;
  text-align: center;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  animation: modalSlideUp 0.3s ease-out;
}

@keyframes modalSlideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.donate-modal__title {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 4px;
}

.donate-modal__desc {
  font-size: 13px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

.donate-modal__qr {
  width: 100%;
  max-width: 240px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.donate-modal__close {
  background: var(--color-text);
  color: white;
  border: none;
  border-radius: 10px;
  padding: 12px 32px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: opacity 0.2s ease;
}

.donate-modal__close:hover {
  opacity: 0.85;
}