/* ===========================
   raryosu.info — Stylesheet
   Minimal & Clean Portfolio
   =========================== */

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

/* Design Tokens */
:root {
  --color-text: #1a1a1a;
  --color-text-secondary: #555;
  --color-text-muted: #777;
  --color-bg: #ffffff;
  --color-bg-subtle: #f7f7f7;
  --color-accent: #4a6fa5;
  --color-accent-hover: #3b5d8a;
  --color-border: #e5e5e5;
  --color-border-light: #f0f0f0;

  --font-heading: 'Instrument Serif', serif;
  --font-body: 'Inter', 'Noto Sans JP', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', monospace;

  --max-width: 720px;
  --max-width-wide: 960px;
  --nav-height: 56px;
}

/* i18n: hide inactive language */
html[lang="en"] [data-lang-jp] { display: none !important; }
html[lang="ja"] [data-lang-en] { display: none !important; }

/* Base */
html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 24px);
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 400;
  line-height: 1.3;
}

h2 {
  font-size: 28px;
  margin-bottom: 32px;
  color: var(--color-text);
}

h3 {
  font-size: 20px;
  margin-bottom: 8px;
  color: var(--color-text);
}

p {
  margin-bottom: 12px;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.container--wide {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 24px;
}

/* Navigation */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  height: var(--nav-height);
}

.nav__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.nav__links a {
  font-size: 14px;
  color: var(--color-text-secondary);
  text-decoration: none;
  white-space: nowrap;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.nav__links a:hover {
  color: var(--color-text);
  text-decoration: none;
  border-bottom-color: var(--color-accent);
}

.nav__lang {
  display: flex;
  align-items: center;
  gap: 0;
  flex-shrink: 0;
  margin-left: 24px;
}

.nav__lang button {
  background: none;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 13px;
  font-family: var(--font-body);
  padding: 4px 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.nav__lang button:first-child {
  border-radius: 4px 0 0 4px;
  border-right: none;
}

.nav__lang button:last-child {
  border-radius: 0 4px 4px 0;
}

.nav__lang button.active {
  background-color: var(--color-text);
  color: var(--color-bg);
  border-color: var(--color-text);
}

.nav__lang button:hover:not(.active) {
  background-color: var(--color-bg-subtle);
  color: var(--color-text);
}

/* Sections */
.section {
  padding: 80px 0;
}

.section--alt {
  background-color: var(--color-bg-subtle);
}

.section__divider {
  border: none;
  border-top: 1px solid var(--color-border-light);
  margin: 0;
}

/* Hero Section */
.hero {
  padding: 100px 0 80px;
  text-align: center;
}

.hero__image {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  margin-bottom: 24px;
  filter: grayscale(20%);
}

.hero__name {
  font-family: var(--font-heading);
  font-size: 42px;
  font-weight: 400;
  margin-bottom: 8px;
  color: var(--color-text);
  letter-spacing: -0.5px;
}

.hero__title {
  font-size: 18px;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
  font-weight: 400;
}

.hero__tagline {
  max-width: 540px;
  margin: 0 auto 32px;
  font-size: 16px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.hero__badges {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.hero__badge:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

/* About Section */
.about__text {
  max-width: var(--max-width);
  margin: 0 auto;
}

.about__text p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}

.about__contact {
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border-light);
}

.about__contact a {
  font-family: var(--font-mono);
  font-size: 15px;
}

/* Expertise Cards */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.expertise-card {
  padding: 28px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.expertise-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.expertise-card h3 {
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--color-text);
}

.expertise-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* Project Cards */
.projects-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.project-card {
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

.project-card h3 {
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 12px;
}

.project-card p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* Career Timeline */
.timeline {
  position: relative;
  padding-left: 28px;
  border-left: 2px solid var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: 40px;
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__item::before {
  content: '';
  position: absolute;
  left: -33px;
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-accent);
  border: 2px solid var(--color-bg);
  outline: 2px solid var(--color-accent);
}

.timeline__company {
  font-family: var(--font-body);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 2px;
}

.timeline__role {
  font-size: 15px;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
}

.timeline__period {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.timeline__desc {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.timeline__desc ul {
  list-style: none;
  padding: 0;
}

.timeline__desc li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 4px;
}

.timeline__desc li::before {
  content: '\2013';
  position: absolute;
  left: 0;
  color: var(--color-text-muted);
}

/* Certifications */
.cert-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.cert-item {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.cert-item__name {
  font-weight: 600;
  font-size: 16px;
}

.cert-item__issuer {
  font-size: 14px;
  color: var(--color-text-muted);
}

.cert-item a {
  font-size: 13px;
  font-family: var(--font-mono);
}

/* Writing & Talks Lists */
.pub-list {
  list-style: none;
}

.pub-list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--color-border-light);
  display: flex;
  align-items: baseline;
  gap: 16px;
}

.pub-list li:last-child {
  border-bottom: none;
}

.pub-list__date {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-muted);
  flex-shrink: 0;
  width: 72px;
}

.pub-list__content {
  flex: 1;
}

.pub-list__title {
  font-size: 15px;
  display: block;
  margin-bottom: 2px;
}

.pub-list__venue {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* Footer */
.footer {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer__links {
  display: flex;
  justify-content: center;
  gap: 24px;
  list-style: none;
  margin-bottom: 24px;
}

.footer__links a {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.footer__links a:hover {
  color: var(--color-accent);
}

.footer__lang {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 16px;
}

.footer__lang button {
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 2px 4px;
}

.footer__lang button.active {
  color: var(--color-text);
  font-weight: 600;
}

.footer__lang span {
  color: var(--color-text-muted);
  font-size: 13px;
}

.footer__copy {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* Mobile Nav Toggle */
.nav__toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  color: var(--color-text);
}

.nav__toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: currentColor;
  margin: 4px 0;
  transition: transform 0.2s ease;
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --nav-height: 48px;
  }

  .hero {
    padding: 72px 0 56px;
  }

  .hero__name {
    font-size: 32px;
  }

  .hero__title {
    font-size: 16px;
  }

  .section {
    padding: 56px 0;
  }

  h2 {
    font-size: 24px;
    margin-bottom: 24px;
  }

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

  .nav__toggle {
    display: block;
  }

  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    flex-direction: column;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 24px;
    gap: 12px;
  }

  .nav__links.open {
    display: flex;
  }

  .nav__lang {
    margin-left: 0;
  }

  .pub-list li {
    flex-direction: column;
    gap: 4px;
  }

  .pub-list__date {
    width: auto;
  }

  .cert-item {
    flex-direction: column;
    gap: 4px;
  }

  .timeline {
    padding-left: 20px;
  }

  .timeline__item::before {
    left: -25px;
  }

  .container,
  .container--wide {
    padding: 0 16px;
  }
}

@media (max-width: 480px) {
  .hero__name {
    font-size: 28px;
  }

  .hero__badges {
    flex-direction: column;
    align-items: center;
  }

  .footer__links {
    flex-direction: column;
    gap: 12px;
  }
}