@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@300;400;500;700&family=Noto+Serif+JP:wght@400;500;600;700&display=swap');

/* ============================================================
   RESET & ROOT
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --c-bg: #1a1a2e;
  --c-accent: #e94560;
  --c-light: #f5f5f0;
  --c-bg2: #16213e;
  --c-bg3: #0f3460;
  --c-muted: rgba(245,245,240,0.45);
  --c-border: rgba(245,245,240,0.1);
  --nav-w: 220px;
  --font-serif: 'Noto Serif JP', 'Georgia', serif;
  --font-sans: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', system-ui, sans-serif;
  --radius: 10px;
  --transition: 0.35s cubic-bezier(0.4,0,0.2,1);
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background: var(--c-bg);
  color: var(--c-light);
}

body.body-dark {
  font-family: var(--font-sans);
  background: var(--c-bg);
  color: var(--c-light);
  line-height: 1.7;
  overflow-x: hidden;
}

/* scroll-margin for fixed sidenav (mobile: top nav ~60px, desktop: left nav no shift) */
div[id] {
  scroll-margin-top: 70px;
}

/* ============================================================
   LAYOUT WRAPPER
   ============================================================ */
.site-wrapper {
  display: flex;
  min-height: 100vh;
}

/* ============================================================
   LEFT SIDEBAR NAV
   ============================================================ */
.sidenav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--nav-w);
  height: 100vh;
  background: var(--c-bg2);
  border-right: 1px solid var(--c-border);
  display: flex;
  flex-direction: column;
  z-index: 200;
  padding: 0;
  overflow: hidden;
}

.sidenav-brand {
  padding: 24px 16px 16px;
  border-bottom: 1px solid var(--c-border);
  flex-shrink: 0;
}

.brand-link {
  display: block;
  text-decoration: none;
  margin-bottom: 10px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--c-accent);
  color: var(--c-light);
  font-family: var(--font-serif);
  font-size: 1.5rem;
  font-weight: 700;
  border-radius: var(--radius);
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  object-fit: cover;
}

.sidenav-tagline {
  font-size: 0.65rem;
  color: var(--c-muted);
  letter-spacing: 0.05em;
  overflow: hidden;
  white-space: nowrap;
}

.tagline-ticker {
  display: inline-block;
  animation: ticker-slide 12s linear infinite;
}

@keyframes ticker-slide {
  0%   { transform: translateX(0); }
  40%  { transform: translateX(0); }
  60%  { transform: translateX(-30%); }
  100% { transform: translateX(0); }
}

/* nav details / summary / menu */
.nav-details {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
}

.nav-summary {
  display: flex;
  align-items: center;
  padding: 14px 18px;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--c-muted);
  cursor: pointer;
  list-style: none;
  user-select: none;
  border-bottom: 1px solid var(--c-border);
  min-height: 44px;
}

.nav-summary::-webkit-details-marker { display: none; }

.nav-toggle-icon {
  font-size: 1.2rem;
  color: var(--c-accent);
  margin-right: 8px;
  line-height: 1;
}

.nav-menu {
  list-style: none;
  padding: 12px 0;
  flex: 1;
}

.nav-menu li {
  margin: 2px 0;
}

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  text-decoration: none;
  color: var(--c-light);
  font-size: 0.88rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  border-radius: 0 var(--radius) var(--radius) 0;
  transition: background var(--transition), color var(--transition);
  min-height: 44px;
}

.nav-link:hover,
.nav-link:focus-visible {
  background: rgba(233,69,96,0.15);
  color: var(--c-accent);
  outline: none;
}

.nav-icon {
  color: var(--c-accent);
  font-size: 0.75rem;
  transition: transform var(--transition);
}

.nav-link:hover .nav-icon {
  transform: translateX(3px);
}

.nav-text {
  flex: 1;
}

/* ============================================================
   CONTENT AREA
   ============================================================ */
.content-area {
  margin-left: var(--nav-w);
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: flex-end;
  background: var(--c-bg);
  overflow: hidden;
}

/* diagonal color band */
.hero-diagonal {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--c-bg) 0%, var(--c-bg) 48%, var(--c-accent) 48%, var(--c-accent) 54%, var(--c-bg3) 54%, var(--c-bg3) 100%);
  opacity: 0.35;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  padding: 80px 56px 100px;
  max-width: 820px;
  text-align: left;
}

.hero-eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  color: var(--c-accent);
  text-transform: uppercase;
  margin-bottom: 20px;
  font-family: var(--font-sans);
  font-weight: 300;
}

.hero-h1 {
  font-family: var(--font-serif);
  font-size: clamp(2.4rem, 6vw, 5.5rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 28px;
  background: linear-gradient(135deg, var(--c-light) 0%, var(--c-accent) 80%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--c-muted);
  margin-bottom: 40px;
  max-width: 520px;
  line-height: 1.8;
  font-weight: 300;
}

.hero-cta {
  display: inline-block;
  background: var(--c-accent);
  color: var(--c-light);
  padding: 14px 36px;
  border-radius: var(--radius);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  min-height: 44px;
  line-height: 1.6;
}

.hero-cta:hover,
.hero-cta:focus-visible {
  background: #ff6b85;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(233,69,96,0.4);
  outline: none;
}

.hero-scroll-hint {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  color: var(--c-accent);
  font-size: 1.4rem;
  animation: bounce-down 2s ease-in-out infinite;
}

@keyframes bounce-down {
  0%, 100% { transform: translateX(-50%) translateY(0); opacity: 0.7; }
  50%       { transform: translateX(-50%) translateY(8px); opacity: 1; }
}

/* kinetic text animations */
.kinetic-title {
  animation: kinetic-in 1s cubic-bezier(0.22,1,0.36,1) both;
}

.kinetic-sub {
  animation: kinetic-in 1s 0.2s cubic-bezier(0.22,1,0.36,1) both;
}

.kinetic-char {
  animation: kinetic-in 1s 0.1s cubic-bezier(0.22,1,0.36,1) both;
}

@keyframes kinetic-in {
  from { opacity: 0; transform: translateY(32px) skewY(2deg); }
  to   { opacity: 1; transform: translateY(0) skewY(0); }
}

/* ============================================================
   MAIN CONTENT (main > article > div)
   ============================================================ */
.main-content {
  display: flex;
  flex-direction: row;
  gap: 0;
  flex: 1;
  background: var(--c-bg);
}

/* ASIDE — left of content */
.content-aside {
  width: 200px;
  flex-shrink: 0;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  background: var(--c-bg2);
  border-right: 1px solid var(--c-border);
  padding: 40px 0 40px;
}

.aside-inner {
  padding: 0 16px;
}

.aside-eyebrow {
  display: block;
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  color: var(--c-accent);
  margin-bottom: 6px;
  font-weight: 500;
}

.aside-title {
  font-family: var(--font-serif);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--c-light);
  margin-bottom: 18px;
  letter-spacing: 0.04em;
}

.aside-links {
  list-style: none;
}

.aside-links li {
  margin-bottom: 4px;
}

.aside-link {
  display: block;
  padding: 8px 10px;
  font-size: 0.78rem;
  color: var(--c-muted);
  text-decoration: none;
  border-radius: var(--radius);
  transition: background var(--transition), color var(--transition);
  min-height: 40px;
  line-height: 1.5;
  display: flex;
  align-items: center;
}

.aside-link:hover,
.aside-link:focus-visible {
  background: rgba(233,69,96,0.12);
  color: var(--c-accent);
  outline: none;
}

/* main article */
.main-article {
  flex: 1;
  min-width: 0;
  padding: 60px 48px 80px;
  max-width: 900px;
}

.content-section {
  /* direct child of article */
}

/* ============================================================
   CONTENT TYPOGRAPHY (page.content 渲染结果)
   ============================================================ */
.content-section h2,
.main-article h2 {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--c-light);
  margin: 56px 0 20px;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.content-section h3,
.main-article h3 {
  font-family: var(--font-serif);
  font-size: clamp(1.15rem, 2.2vw, 1.55rem);
  font-weight: 600;
  color: var(--c-light);
  margin: 36px 0 14px;
  letter-spacing: 0.01em;
}

.content-section p,
.main-article p {
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(245,245,240,0.88);
  margin-bottom: 18px;
}

.content-section a,
.main-article a {
  color: var(--c-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

.content-section a:hover,
.main-article a:hover {
  color: #ff8fa0;
}

.content-section ul,
.content-section ol,
.main-article ul,
.main-article ol {
  padding-left: 1.6em;
  margin-bottom: 18px;
}

.content-section li,
.main-article li {
  margin-bottom: 8px;
  line-height: 1.75;
  color: rgba(245,245,240,0.85);
}

.content-section strong,
.main-article strong {
  color: var(--c-light);
  font-weight: 700;
}

.content-section em,
.main-article em {
  color: var(--c-accent);
  font-style: italic;
}

/* sections in page.content */
.content-section div {
  padding: 48px 0;
  border-bottom: 1px solid var(--c-border);
}

.content-section div:last-child {
  border-bottom: none;
}

/* cards that might be inside content */
.content-section .card,
.main-article .card {
  background: var(--c-bg2);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 20px;
}

/* ============================================================
   REVEAL ANIMATION (scroll-triggered via JS)
   ============================================================ */
.reveal-section {
  opacity: 1;
}

.reveal-item {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal-item.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   FOOTER: footer > div × n
   ============================================================ */
.site-footer {
  background: var(--c-bg2);
  border-top: 1px solid var(--c-border);
}

.footer-contact-section {
  padding: 40px 48px;
  border-bottom: 1px solid var(--c-border);
}

.footer-contact-inner {
  display: flex;
  align-items: center;
  gap: 32px;
  flex-wrap: wrap;
}

.footer-contact-block {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-contact-item {
  font-size: 0.85rem;
  color: var(--c-muted);
}

.footer-slogan {
  font-family: var(--font-serif);
  font-size: 1rem;
  color: var(--c-accent);
  font-weight: 600;
  letter-spacing: 0.08em;
}

.footer-copy-section {
  padding: 20px 48px;
  text-align: center;
}

.footer-copy {
  font-size: 0.78rem;
  color: var(--c-muted);
  letter-spacing: 0.05em;
}

/* ============================================================
   SMALL eyebrow (契约: small 紧邻 h2 之前)
   ============================================================ */
small.aside-eyebrow,
.content-section small,
.main-article small {
  display: block;
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  color: var(--c-accent);
  font-weight: 500;
  margin-bottom: 6px;
  font-family: var(--font-sans);
}

/* ============================================================
   RESPONSIVE — TABLET
   ============================================================ */
@media (max-width: 1024px) {
  :root { --nav-w: 180px; }

  .main-article {
    padding: 48px 32px 64px;
  }

  .content-aside {
    width: 160px;
  }

  .footer-contact-section,
  .footer-copy-section {
    padding-left: 32px;
    padding-right: 32px;
  }
}

/* ============================================================
   RESPONSIVE — MOBILE (≤768px)
   ============================================================ */
@media (max-width: 768px) {
  :root { --nav-w: 0px; }

  .sidenav {
    width: 100%;
    height: auto;
    position: fixed;
    top: 0;
    left: 0;
    flex-direction: row;
    align-items: center;
    border-right: none;
    border-bottom: 1px solid var(--c-border);
    z-index: 300;
    overflow: visible;
  }

  .sidenav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    border-bottom: none;
    border-right: 1px solid var(--c-border);
    flex-shrink: 0;
  }

  .sidenav-tagline {
    display: none;
  }

  .nav-details {
    flex: 1;
    overflow: visible;
    position: relative;
  }

  .nav-summary {
    padding: 0 16px;
    min-height: 56px;
    display: flex;
    align-items: center;
    border-bottom: none;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--c-bg2);
    border-bottom: 1px solid var(--c-border);
    padding: 8px 0;
    z-index: 100;
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
  }

  .content-area {
    margin-left: 0;
    margin-top: 56px;
  }

  .hero {
    min-height: 100svh;
    align-items: flex-end;
  }

  .hero-inner {
    padding: 60px 24px 80px;
  }

  .hero-h1 {
    font-size: clamp(2rem, 8vw, 3.2rem);
  }

  .main-content {
    flex-direction: column;
  }

  .content-aside {
    width: 100%;
    height: auto;
    position: static;
    border-right: none;
    border-bottom: 1px solid var(--c-border);
    padding: 24px 0 20px;
  }

  .aside-inner {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    padding: 0 20px;
  }

  .aside-eyebrow,
  .aside-title {
    width: 100%;
    margin-bottom: 4px;
  }

  .aside-links {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
  }

  .aside-links li {
    margin: 0;
  }

  .aside-link {
    padding: 8px 12px;
    font-size: 0.75rem;
    background: var(--c-bg3);
    border-radius: var(--radius);
    min-height: 40px;
  }

  .main-article {
    padding: 36px 20px 60px;
  }

  .footer-contact-section,
  .footer-copy-section {
    padding-left: 20px;
    padding-right: 20px;
  }

  .footer-contact-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  div[id] {
    scroll-margin-top: 60px;
  }
}

/* ============================================================
   PREFERS-REDUCED-MOTION
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html { scroll-behavior: auto; }
}

button[aria-expanded]{min-width:44px;min-height:44px}