/* ============================================
   kuragekun.dev — stylesheet
   aesthetic: 水色, soft, aquarium glass
   ============================================ */

:root {
  --water-light: #e8f4f8;
  --water: #b8dce8;
  --water-mid: #89c4d8;
  --water-deep: #5a9bb5;
  --water-dark: #2c6e8a;
  --ink: #2a3a4a;
  --ink-soft: #4a6a7a;
  --ink-faint: #8aaaba;
  --white: #fafcfd;
  --glow: rgba(137, 196, 216, 0.15);
  --glass: rgba(255, 255, 255, 0.55);
  --glass-border: rgba(184, 220, 232, 0.4);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Zen Kaku Gothic New', 'Hiragino Kaku Gothic ProN', sans-serif;
  font-weight: 300;
  color: var(--ink);
  background: linear-gradient(
    180deg,
    var(--water-light) 0%,
    var(--white) 30%,
    var(--white) 70%,
    var(--water-light) 100%
  );
  min-height: 100vh;
  line-height: 1.8;
  letter-spacing: 0.01em;
  overflow-x: hidden;
}

/* --- floating jellyfish background --- */

.jellyfish-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.jelly {
  position: absolute;
  font-size: 2rem;
  opacity: 0.08;
  animation: drift linear infinite;
}

.j1 {
  left: 8%;
  top: -5%;
  font-size: 2.5rem;
  animation-duration: 28s;
  animation-delay: 0s;
}

.j2 {
  left: 55%;
  top: -8%;
  font-size: 1.8rem;
  animation-duration: 35s;
  animation-delay: -8s;
}

.j3 {
  left: 82%;
  top: -3%;
  font-size: 2rem;
  animation-duration: 32s;
  animation-delay: -15s;
}

@keyframes drift {
  0% {
    transform: translateY(-10vh) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 0.08;
  }
  90% {
    opacity: 0.08;
  }
  100% {
    transform: translateY(110vh) rotate(15deg);
    opacity: 0;
  }
}

/* --- header --- */

.site-header {
  position: relative;
  z-index: 10;
  padding: 3rem 2rem 2rem;
  text-align: center;
}

.header-inner {
  max-width: 600px;
  margin: 0 auto;
}

.site-title {
  font-size: 2.4rem;
  font-weight: 400;
  color: var(--water-dark);
  letter-spacing: 0.08em;
  margin-bottom: 0.2rem;
}

.site-subtitle {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.8rem;
  font-weight: 300;
  color: var(--ink-faint);
  letter-spacing: 0.15em;
  margin-bottom: 2rem;
}

.site-nav {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.nav-link {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.78rem;
  font-weight: 300;
  color: var(--ink-soft);
  text-decoration: none;
  letter-spacing: 0.05em;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--water-dark);
  border-bottom-color: var(--water-mid);
}

/* --- main content --- */

.content {
  position: relative;
  z-index: 10;
  max-width: 620px;
  margin: 0 auto;
  padding: 2rem 2rem 4rem;
}

/* --- hero --- */

.hero {
  padding: 3rem 0 4rem;
  text-align: center;
}

.hero-greeting {
  font-size: 1.6rem;
  font-weight: 400;
  color: var(--water-dark);
  margin-bottom: 1.2rem;
}

.hero-line {
  font-size: 1rem;
  color: var(--ink-soft);
  line-height: 2;
}

.hero-line.quiet {
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--ink-faint);
  letter-spacing: 0.05em;
}

/* --- sections --- */

.home-section {
  margin-bottom: 3.5rem;
}

.section-heading {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  font-weight: 400;
  color: var(--ink-faint);
  letter-spacing: 0.15em;
  text-transform: lowercase;
  margin-bottom: 1.2rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--glass-border);
}

/* --- entry preview --- */

.entry-preview {
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  padding: 1.8rem 2rem;
  transition: box-shadow 0.3s ease;
}

.entry-preview:hover {
  box-shadow: 0 4px 24px var(--glow);
}

.entry-tag {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--water-deep);
  background: var(--water-light);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  letter-spacing: 0.08em;
}

.entry-title {
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--water-dark);
  margin: 0.8rem 0 1rem;
}

.entry-excerpt {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 2;
}

.read-more {
  display: inline-block;
  margin-top: 1.2rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--water-deep);
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: color 0.3s ease;
}

.read-more:hover {
  color: var(--water-dark);
}

/* --- soft text --- */

.soft-text {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 2;
}

/* --- entry page styles --- */

.entries-list {
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.entry {
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--glass-border);
}

.entry:last-child {
  border-bottom: none;
}

.entry-number {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--water-deep);
  letter-spacing: 0.1em;
  margin-bottom: 0.4rem;
}

.entry .entry-title {
  font-size: 1.3rem;
  margin: 0.4rem 0 1.2rem;
}

.entry-body {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 2.2;
}

.entry-body p {
  margin-bottom: 1rem;
}

.entry-body p:last-child {
  margin-bottom: 0;
}

.entry-note {
  margin-top: 1.5rem;
  padding: 1rem 1.4rem;
  background: var(--water-light);
  border-radius: 8px;
  font-size: 0.82rem;
  color: var(--ink-faint);
  line-height: 1.8;
  font-family: 'IBM Plex Mono', monospace;
}

/* --- about page --- */

.about-section {
  margin-bottom: 2.5rem;
}

.about-section h2 {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--water-dark);
  margin-bottom: 1rem;
}

.about-section p {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 2;
}

.about-detail {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.8rem;
  color: var(--ink-faint);
  line-height: 2;
  margin-top: 1rem;
  padding: 1.2rem 1.4rem;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: 8px;
}

/* --- footer --- */

.site-footer {
  position: relative;
  z-index: 10;
  text-align: center;
  padding: 3rem 2rem;
  color: var(--ink-faint);
  font-size: 0.8rem;
}

.footer-sub {
  font-size: 0.72rem;
  margin-top: 0.3rem;
  opacity: 0.7;
}

/* --- page header (non-home) --- */

.page-header {
  margin-bottom: 3rem;
}

.page-title {
  font-size: 1.6rem;
  font-weight: 400;
  color: var(--water-dark);
  margin-bottom: 0.4rem;
}

.page-desc {
  font-size: 0.85rem;
  color: var(--ink-faint);
}

/* --- responsive --- */

@media (max-width: 640px) {
  .site-header {
    padding: 2rem 1.2rem 1.5rem;
  }

  .content {
    padding: 1.5rem 1.2rem 3rem;
  }

  .site-title {
    font-size: 2rem;
  }

  .hero-greeting {
    font-size: 1.3rem;
  }

  .site-nav {
    gap: 1.2rem;
  }

  .entry-preview {
    padding: 1.4rem 1.2rem;
  }
}