/* ============================================================
   Design System
   ============================================================ */

:root {
  /* Typography */
  --font-heading: "Noto Serif", "Georgia", serif;
  --font-body: "Inter", system-ui, -apple-system, sans-serif;

  /* Spacing scale (4px base) */
  --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;
  --space-5xl: 8rem;

  /* Radii */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;

  /* Transitions */
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 150ms;
  --duration-normal: 400ms;
  --duration-slow: 800ms;

  /* Light mode — warm stone palette */
  --color-bg: #f8f6f3;
  --color-bg-raised: #ffffff;
  --color-text: #2c2825;
  --color-text-secondary: #5c554e;
  --color-text-tertiary: #9a918a;
  --color-border: #e8e3dd;
  --color-border-subtle: #f0ece7;
  --color-accent: #6b7c5e;
  --color-accent-soft: rgba(107, 124, 94, 0.07);
  --color-surface-hover: rgba(44, 40, 37, 0.03);
  --shadow-sm: 0 1px 3px rgba(44, 40, 37, 0.04);
  --shadow-md: 0 4px 16px rgba(44, 40, 37, 0.06);
  --shadow-lg: 0 8px 30px rgba(44, 40, 37, 0.08);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #121110;
    --color-bg-raised: #1e1c1a;
    --color-text: #e8e3dd;
    --color-text-secondary: #a39a92;
    --color-text-tertiary: #6e665f;
    --color-border: #2a2724;
    --color-border-subtle: #1e1c1a;
    --color-accent: #8fa47e;
    --color-accent-soft: rgba(143, 164, 126, 0.08);
    --color-surface-hover: rgba(232, 227, 221, 0.04);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.35);
  }
}

[data-theme="dark"] {
  --color-bg: #121110;
  --color-bg-raised: #1e1c1a;
  --color-text: #e8e3dd;
  --color-text-secondary: #a39a92;
  --color-text-tertiary: #6e665f;
  --color-border: #2a2724;
  --color-border-subtle: #1e1c1a;
  --color-accent: #8fa47e;
  --color-accent-soft: rgba(143, 164, 126, 0.08);
  --color-surface-hover: rgba(232, 227, 221, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.35);
}

[data-theme="light"] {
  --color-bg: #f8f6f3;
  --color-bg-raised: #ffffff;
  --color-text: #2c2825;
  --color-text-secondary: #5c554e;
  --color-text-tertiary: #9a918a;
  --color-border: #e8e3dd;
  --color-border-subtle: #f0ece7;
  --color-accent: #6b7c5e;
  --color-accent-soft: rgba(107, 124, 94, 0.07);
  --color-surface-hover: rgba(44, 40, 37, 0.03);
  --shadow-sm: 0 1px 3px rgba(44, 40, 37, 0.04);
  --shadow-md: 0 4px 16px rgba(44, 40, 37, 0.06);
  --shadow-lg: 0 8px 30px rgba(44, 40, 37, 0.08);
}

/* ============================================================
   Reset & Base
   ============================================================ */

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--duration-normal) var(--ease-out),
    color var(--duration-normal) var(--ease-out);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--duration-normal) var(--ease-out);
}

a:hover {
  color: var(--color-text);
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ============================================================
   Layout
   ============================================================ */

.container {
  width: 100%;
  max-width: 680px;
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

section {
  padding: var(--space-5xl) 0;
}

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

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--color-border-subtle);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: color-mix(in srgb, var(--color-bg) 80%, transparent);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.nav-wordmark {
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--color-text);
  letter-spacing: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.nav-links a {
  font-size: 0.85rem;
  color: var(--color-text-tertiary);
  font-weight: 450;
  letter-spacing: 0.01em;
  transition: color var(--duration-normal) var(--ease-out);
}

.nav-links a:hover {
  color: var(--color-text);
}

.theme-toggle {
  appearance: none;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--color-text-tertiary);
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--duration-normal) var(--ease-out);
}

.theme-toggle:hover {
  color: var(--color-text);
}

.theme-toggle .icon-sun {
  display: none;
}

[data-theme="dark"] .theme-toggle .icon-sun,
:root:not([data-theme="light"]) .theme-toggle .icon-sun {
  display: block;
}

[data-theme="dark"] .theme-toggle .icon-moon,
:root:not([data-theme="light"]) .theme-toggle .icon-moon {
  display: none;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .theme-toggle .icon-sun {
    display: none;
  }
  :root:not([data-theme="dark"]) .theme-toggle .icon-moon {
    display: block;
  }
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .icon-sun {
    display: block;
  }
  :root:not([data-theme="light"]) .theme-toggle .icon-moon {
    display: none;
  }
}

/* ============================================================
   Hero
   ============================================================ */

.hero {
  padding: var(--space-5xl) 0 var(--space-4xl);
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.25rem, 5vw, 3rem);
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.hero-tagline {
  font-family: var(--font-heading);
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-weight: 400;
  font-style: italic;
  line-height: 1.5;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2xl);
}

.hero-rule {
  width: 48px;
  height: 1px;
  background: var(--color-border);
  margin-bottom: var(--space-2xl);
}

.hero-bio {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--color-text-secondary);
  max-width: 560px;
}

/* ============================================================
   Section Headers
   ============================================================ */

.section-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-tertiary);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 1.85rem);
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-2xl);
}

/* ============================================================
   App Cards
   ============================================================ */

#apps-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.app-card {
  display: flex;
  gap: var(--space-xl);
  padding: var(--space-xl) var(--space-2xl);
  background: var(--color-bg-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--duration-normal) var(--ease-out),
    transform var(--duration-normal) var(--ease-out),
    border-color var(--duration-normal) var(--ease-out);
}

.app-card-link {
  display: block;
  text-decoration: none;
  color: inherit;
  border-radius: var(--radius-md);
}

.app-card-link .app-card {
  cursor: pointer;
}

.app-card:hover,
.app-card-link:hover .app-card {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  border-color: var(--app-accent, var(--color-accent));
}

.app-card--featured {
  padding: var(--space-2xl) var(--space-3xl);
  gap: var(--space-2xl);
}

.app-card--featured .app-icon-wrap {
  width: 96px;
  height: 96px;
}

.app-card--featured .app-icon,
.app-card--featured .app-icon-placeholder {
  width: 96px;
  height: 96px;
  border-radius: var(--radius-lg);
}

.app-card--featured .app-name {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 500;
}

.app-card--featured .app-tagline {
  font-size: 1.05rem;
}

.app-card--featured .app-description {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--color-text-secondary);
}

.app-icon-wrap {
  flex-shrink: 0;
  width: 80px;
  height: 80px;
}

.app-icon {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-md);
  object-fit: cover;
}

.app-icon-placeholder {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-md);
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 500;
  opacity: 0.85;
}

.app-info {
  flex: 1;
  min-width: 0;
}

.app-name {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-xs);
}

.app-name-jp {
  font-weight: 400;
  color: var(--color-text-tertiary);
  margin-left: 0.4em;
  font-size: 0.85em;
}

.app-tagline {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
}

.app-description {
  font-size: 0.9rem;
  color: var(--color-text-tertiary);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.app-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.app-store-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-accent);
  padding: 0.4em 1.2em;
  border: 1px solid var(--color-accent);
  border-radius: 999px;
  transition: background var(--duration-normal) var(--ease-out),
    color var(--duration-normal) var(--ease-out);
}

.app-store-link:hover {
  background: var(--color-accent);
  color: #fff;
}

.app-status {
  font-size: 0.8rem;
  font-weight: 450;
  padding: var(--space-xs) var(--space-md);
  border-radius: 999px;
}

.status-live {
  color: var(--color-accent);
  background: var(--color-accent-soft);
}

.status-testflight {
  color: #7c6f9b;
  background: rgba(124, 111, 155, 0.08);
}

.status-personal {
  color: var(--color-text-tertiary);
  background: var(--color-surface-hover);
}

.status-coming-soon {
  color: var(--color-text-tertiary);
  background: var(--color-surface-hover);
}

/* ============================================================
   About
   ============================================================ */

.about-text {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
  max-width: 580px;
}

.about-text + .about-text {
  margin-top: var(--space-lg);
}

/* ============================================================
   Footer
   ============================================================ */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-2xl) 0 var(--space-3xl);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--color-text-tertiary);
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  transition: color var(--duration-normal) var(--ease-out);
}

.footer-links a:hover {
  color: var(--color-text);
}

/* ============================================================
   Scroll Animations
   ============================================================ */

.fade-in {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

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

@media (max-width: 600px) {
  .container {
    padding: 0 var(--space-lg);
  }

  section {
    padding: var(--space-4xl) 0;
  }

  .hero {
    padding: var(--space-4xl) 0 var(--space-3xl);
  }

  .app-card {
    flex-direction: column;
    gap: var(--space-lg);
    padding: var(--space-xl);
  }

  .app-card--featured {
    padding: var(--space-xl);
    gap: var(--space-lg);
  }

  .app-card--featured .app-icon-wrap {
    width: 72px;
    height: 72px;
  }

  .app-card--featured .app-icon,
  .app-card--featured .app-icon-placeholder {
    width: 72px;
    height: 72px;
  }

  .app-icon-wrap {
    width: 64px;
    height: 64px;
  }

  .app-icon,
  .app-icon-placeholder {
    width: 64px;
    height: 64px;
  }

  .nav-links .nav-link-text {
    display: none;
  }
}

/* ============================================================
   Reduced motion
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }
}