/* ============================================
   SEISIN DOCUMENTATION - DESIGN SYSTEM
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Brand Colors */
  --seisin-primary: #4A9FD9;
  --seisin-primary-light: #6BB3E0;
  --seisin-primary-dark: #3A8BC4;
  --seisin-primary-glow: rgba(74, 159, 217, 0.4);

  /* Semantic Colors */
  --seisin-success: #34C759;
  --seisin-warning: #FF9500;
  --seisin-error: #FF3B30;
  --seisin-info: #5AC8FA;

  /* Neutral Palette */
  --seisin-bg-dark: rgb(18, 18, 20);
  --seisin-bg-elevated: rgb(28, 28, 30);
  --seisin-bg-card: rgb(38, 38, 42);
  --seisin-bg-hover: rgb(48, 48, 54);

  --seisin-text-primary: rgb(242, 242, 247);
  --seisin-text-secondary: rgb(174, 174, 178);
  --seisin-text-tertiary: rgb(99, 99, 102);

  --seisin-border: rgba(255, 255, 255, 0.08);
  --seisin-border-subtle: rgba(255, 255, 255, 0.04);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 100px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px var(--seisin-primary-glow);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Material MkDocs Overrides */
  --md-primary-fg-color: var(--seisin-primary);
  --md-primary-fg-color--light: var(--seisin-primary-light);
  --md-primary-fg-color--dark: var(--seisin-primary-dark);
  --md-accent-fg-color: var(--seisin-primary);
  --md-accent-fg-color--transparent: rgba(74, 159, 217, 0.1);
}

[data-md-color-scheme="slate"] {
  --md-default-bg-color: var(--seisin-bg-dark);
  --md-default-fg-color: var(--seisin-text-primary);
  --md-default-fg-color--light: var(--seisin-text-secondary);
  --md-default-fg-color--lighter: var(--seisin-text-tertiary);
  --md-default-fg-color--lightest: var(--seisin-border);
  --md-code-bg-color: var(--seisin-bg-card);
  --md-code-fg-color: var(--seisin-text-primary);
  --md-typeset-color: var(--seisin-text-secondary);
  --md-footer-bg-color: var(--seisin-bg-dark);
  --md-footer-bg-color--dark: var(--seisin-bg-dark);
}

/* --- Base Styles --- */
body {
  font-feature-settings: "kern" 1, "liga" 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.md-header {
  background: var(--seisin-bg-dark);
  border-bottom: 1px solid var(--seisin-border-subtle);
  backdrop-filter: blur(20px);
}

.md-sidebar {
  background: var(--seisin-bg-dark);
}

.md-content {
  background: var(--seisin-bg-dark);
}

.md-typeset a {
  color: var(--seisin-primary);
  transition: color var(--transition-fast);
}

.md-typeset a:hover {
  color: var(--seisin-primary-light);
}

/* Hide TOC on homepage */
.md-sidebar--secondary {
  display: none;
}

/* --- Hero Section --- */
.hero-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4xl);
  align-items: center;
  padding: var(--space-4xl) var(--space-xl);
  margin: -1.5rem -1rem var(--space-3xl) -1rem;
  background: linear-gradient(
    135deg,
    rgba(74, 159, 217, 0.08) 0%,
    rgba(74, 159, 217, 0.02) 50%,
    transparent 100%
  );
  border-radius: 0 0 var(--radius-xl) var(--radius-xl);
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(
    ellipse at center,
    rgba(74, 159, 217, 0.08) 0%,
    transparent 70%
  );
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.logo-mark {
  margin-bottom: var(--space-lg);
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--seisin-primary) 0%, var(--seisin-primary-dark) 100%);
  border-radius: var(--radius-md);
  font-size: 1.75rem;
  font-weight: 700;
  color: white;
  box-shadow: var(--shadow-md), var(--shadow-glow);
}

.hero-section h1 {
  font-size: 4rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: 0 0 var(--space-md) 0;
  background: linear-gradient(135deg, var(--seisin-text-primary) 0%, var(--seisin-text-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: 1.5rem;
  font-weight: 500;
  color: var(--seisin-primary);
  margin: 0 0 var(--space-lg) 0;
  letter-spacing: -0.01em;
}

.hero-description {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--seisin-text-secondary);
  margin: 0 0 var(--space-2xl) 0;
  max-width: 480px;
}

/* --- CTA Buttons --- */
.hero-cta {
  display: flex;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.hero-cta p {
  margin: 0;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 1.75rem;
  margin-bottom: var(--space-md);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
}

.cta-primary {
  background: linear-gradient(135deg, var(--seisin-primary) 0%, var(--seisin-primary-dark) 100%);
  color: #ffffff !important;
  box-shadow: var(--shadow-sm), 0 0 20px rgba(74, 159, 217, 0.25);
  font-weight: 700;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

.cta-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md), 0 0 30px rgba(74, 159, 217, 0.4);
  color: #ffffff !important;
  background: linear-gradient(135deg, var(--seisin-primary-light) 0%, var(--seisin-primary) 100%);
}

.cta-secondary {
  background: var(--seisin-bg-card);
  color: var(--seisin-text-primary);
  border: 1px solid var(--seisin-border);
  font-weight: 600;
}

.cta-secondary:hover {
  background: var(--seisin-bg-hover);
  border-color: var(--seisin-primary);
  transform: translateY(-2px);
  color: var(--seisin-primary-light);
}

.cta-large {
  padding: 1.125rem 2.5rem;
  font-size: 1.125rem;
}

/* --- App Preview (Hero Visual) --- */
.hero-visual {
  position: relative;
  z-index: 1;
}

.app-preview {
  perspective: 1000px;
}

.preview-window {
  background: var(--seisin-bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--seisin-border);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: rotateY(-5deg) rotateX(5deg);
  transition: transform var(--transition-slow);
}

.preview-window:hover {
  transform: rotateY(0) rotateX(0);
}

.window-controls {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  background: var(--seisin-bg-elevated);
  border-bottom: 1px solid var(--seisin-border-subtle);
}

.control {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.control.red { background: #FF5F57; }
.control.yellow { background: #FEBC2E; }
.control.green { background: #28C840; }

.preview-content {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  padding: var(--space-xl);
}

.preview-stat {
  text-align: center;
  padding: var(--space-lg);
  background: var(--seisin-bg-elevated);
  border-radius: var(--radius-md);
  border: 1px solid var(--seisin-border-subtle);
}

.stat-value {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--seisin-primary);
  margin-bottom: var(--space-xs);
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  color: var(--seisin-text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* --- Philosophy Section --- */
.philosophy-section {
  padding: var(--space-3xl) 0;
}

.philosophy-section h2 {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--space-3xl);
  color: var(--seisin-text-primary);
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

.philosophy-card {
  padding: var(--space-xl);
  background: var(--seisin-bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--seisin-border);
  transition: all var(--transition-normal);
}

.philosophy-card:hover {
  transform: translateY(-4px);
  border-color: rgba(74, 159, 217, 0.3);
  box-shadow: var(--shadow-md);
}

.philosophy-icon {
  margin-bottom: var(--space-lg);
}

.icon-circle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--seisin-primary) 0%, var(--seisin-primary-dark) 100%);
  border-radius: 50%;
  font-size: 1rem;
  font-weight: 700;
  color: white;
}

.philosophy-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0 0 var(--space-md) 0;
  color: var(--seisin-text-primary);
}

.philosophy-card p {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--seisin-text-secondary);
  margin: 0;
}

/* --- Features Section --- */
.features-section {
  padding: var(--space-3xl) 0;
}

.features-section h2 {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--space-3xl);
  color: var(--seisin-text-primary);
}

.features-showcase {
  display: flex;
  flex-direction: column;
  gap: var(--space-3xl);
}

.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
}

.feature-row.reverse {
  direction: rtl;
}

.feature-row.reverse > * {
  direction: ltr;
}

.feature-content h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 0 0 var(--space-md) 0;
  color: var(--seisin-text-primary);
}

.feature-content p {
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--seisin-text-secondary);
  margin-bottom: var(--space-lg);
}

.feature-content ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.feature-content li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: var(--space-sm);
  color: var(--seisin-text-secondary);
}

.feature-content li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 6px;
  height: 6px;
  background: var(--seisin-primary);
  border-radius: 50%;
}

/* Feature Visual Cards */
.feature-card-preview {
  padding: var(--space-xl);
  background: var(--seisin-bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--seisin-border);
}

.mini-card {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-sm);
  background: var(--seisin-bg-elevated);
  border-radius: var(--radius-md);
  border-left: 3px solid;
}

.mini-card:last-child {
  margin-bottom: 0;
}

.mini-card.alert {
  border-color: var(--seisin-error);
}

.mini-card.info {
  border-color: var(--seisin-warning);
}

.mini-card.success {
  border-color: var(--seisin-success);
}

.mini-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 700;
}

.mini-card.alert .mini-icon {
  background: rgba(255, 59, 48, 0.2);
  color: var(--seisin-error);
}

.mini-card.info .mini-icon {
  background: rgba(255, 149, 0, 0.2);
  color: var(--seisin-warning);
}

.mini-card.success .mini-icon {
  background: rgba(52, 199, 89, 0.2);
  color: var(--seisin-success);
}

.mini-text {
  font-size: 0.9rem;
  color: var(--seisin-text-secondary);
}

/* Payment Preview */
.payment-preview {
  padding: var(--space-lg);
}

.payment-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-md);
  align-items: center;
  padding: var(--space-md) 0;
  border-bottom: 1px solid var(--seisin-border-subtle);
}

.payment-row:last-child {
  border-bottom: none;
}

.payment-date {
  font-size: 0.9rem;
  color: var(--seisin-text-secondary);
}

.payment-status {
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.payment-status.paid {
  background: rgba(52, 199, 89, 0.2);
  color: var(--seisin-success);
}

.payment-status.due {
  background: rgba(74, 159, 217, 0.2);
  color: var(--seisin-primary);
}

.payment-amount {
  text-align: right;
  font-weight: 600;
  color: var(--seisin-text-primary);
}

/* Chart Preview */
.chart-preview {
  display: flex;
  align-items: flex-end;
  justify-content: space-around;
  height: 160px;
  padding-top: var(--space-lg);
}

.chart-bar {
  width: 48px;
  height: var(--height);
  background: linear-gradient(180deg, var(--seisin-primary) 0%, var(--seisin-primary-dark) 100%);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  position: relative;
}

.chart-bar span {
  position: absolute;
  bottom: -24px;
  font-size: 0.75rem;
  color: var(--seisin-text-tertiary);
}

/* --- Capabilities Section --- */
.capabilities-section {
  padding: var(--space-3xl) 0;
}

.capabilities-section h2 {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--space-3xl);
  color: var(--seisin-text-primary);
}

.capabilities-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.capability {
  padding: var(--space-xl);
  background: var(--seisin-bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--seisin-border);
  transition: all var(--transition-normal);
}

.capability:hover {
  transform: translateY(-4px);
  border-color: rgba(74, 159, 217, 0.3);
  box-shadow: var(--shadow-md);
}

.capability strong {
  display: block;
  font-size: 1rem;
  color: var(--seisin-primary);
  margin-bottom: var(--space-sm);
}

.capability p {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--seisin-text-secondary);
  margin: 0;
}

/* --- Pricing Section --- */
.pricing-section {
  padding: var(--space-3xl) 0;
  text-align: center;
}

.pricing-section h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: var(--space-2xl);
  color: var(--seisin-text-primary);
}

.pricing-card {
  max-width: 400px;
  margin: 0 auto;
  padding: var(--space-2xl);
  background: linear-gradient(135deg, var(--seisin-bg-card) 0%, var(--seisin-bg-elevated) 100%);
  border-radius: var(--radius-xl);
  border: 1px solid var(--seisin-border);
  box-shadow: var(--shadow-lg);
}

.pricing-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--seisin-border);
}

.pricing-amount {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--seisin-primary);
  margin-bottom: var(--space-sm);
}

.pricing-note {
  display: block;
  font-size: 0.95rem;
  color: var(--seisin-text-secondary);
}

.pricing-features {
  text-align: left;
  margin-bottom: var(--space-xl);
}

.pricing-features ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.pricing-features li {
  position: relative;
  padding-left: 1.75rem;
  margin-bottom: var(--space-md);
  color: var(--seisin-text-secondary);
}

.pricing-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--seisin-success);
  font-weight: 700;
}

/* --- CTA Final Section --- */
.cta-final {
  padding: var(--space-4xl) var(--space-xl);
  text-align: center;
  background: linear-gradient(135deg, rgba(74, 159, 217, 0.1) 0%, rgba(74, 159, 217, 0.03) 100%);
  border-radius: var(--radius-xl);
  margin: var(--space-3xl) 0;
}

.cta-final h2 {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: var(--space-lg);
  color: var(--seisin-text-primary);
}

.cta-final > p {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--seisin-text-secondary);
  max-width: 560px;
  margin: 0 auto var(--space-2xl) auto;
}

.beta-form {
  margin-bottom: var(--space-lg);
}

.cta-note {
  font-size: 0.9rem;
  color: var(--seisin-text-tertiary);
  margin: 0;
}

/* --- Footer Links --- */
.footer-links {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  padding: var(--space-2xl) 0;
}

.footer-section h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--seisin-text-primary);
  margin-bottom: var(--space-lg);
}

.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-section li {
  margin-bottom: var(--space-sm);
}

.footer-section a {
  color: var(--seisin-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-section a:hover {
  color: var(--seisin-primary);
}

.footer-section p {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--seisin-text-secondary);
  margin: 0;
}

/* --- Responsive Design --- */
@media (max-width: 1024px) {
  .hero-section {
    grid-template-columns: 1fr;
    text-align: center;
    padding: var(--space-3xl) var(--space-lg);
  }

  .hero-content {
    order: 1;
  }

  .hero-visual {
    order: 2;
    margin-top: var(--space-2xl);
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .preview-window {
    transform: none;
  }

  .philosophy-grid {
    grid-template-columns: 1fr;
    gap: var(--space-lg);
  }

  .feature-row,
  .feature-row.reverse {
    grid-template-columns: 1fr;
    direction: ltr;
  }

  .feature-visual {
    order: -1;
  }

  .capabilities-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-links {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
}

@media (max-width: 640px) {
  .hero-section h1 {
    font-size: 2.75rem;
  }

  .hero-tagline {
    font-size: 1.25rem;
  }

  .hero-description {
    font-size: 1rem;
  }

  .preview-content {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
    padding: var(--space-lg);
  }

  .capabilities-grid {
    grid-template-columns: 1fr;
  }

  .cta-button {
    width: 100%;
    max-width: 300px;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
    gap: var(--space-xl);
  }

  .philosophy-section h2,
  .features-section h2,
  .capabilities-section h2,
  .pricing-section h2,
  .cta-final h2 {
    font-size: 2rem;
  }
}

/* --- Utility: Hide default MkDocs elements on homepage --- */
.md-content__inner > h1:first-child {
  display: none;
}

/* --- Smooth scrolling --- */
html {
  scroll-behavior: smooth;
}

/* --- Selection color --- */
::selection {
  background: rgba(74, 159, 217, 0.3);
  color: var(--seisin-text-primary);
}