/* =========================================================
   Tim Rizvanov — AI Integration Advisory
   Editorial redesign 2026 — Inter + Noto Sans JP
   Swiss / print-editorial monochrome aesthetic
   ========================================================= */

:root {
  --bg: #FAFAFA;
  --bg-dark: #0C0C0C;
  --surface: #FFFFFF;
  --surface-soft: #F5F5F5;
  --surface-alt: #F3F3F1;
  --ink: #111114;
  --ink-2: #404047;
  --muted: #888;
  --line: rgba(17, 17, 20, 0.09);
  --line-strong: rgba(17, 17, 20, 0.22);
  --accent: #111114;
  --max-width: 1240px;
  --radius: 0px;
  --radius-lg: 0px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: "Inter", "Noto Sans JP", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: 16px;
  background: var(--ink);
  color: #fff;
  padding: 10px 14px;
  z-index: 200;
  transform: translateY(-200%);
  transition: transform 160ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  list-style: none;
}

p {
  color: var(--ink-2);
  font-size: 0.9375rem;
  line-height: 1.72;
}

h1,
h2,
h3,
h4 {
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--ink);
}

h1 {
  font-size: clamp(3.2rem, 8.5vw, 7.5rem);
  font-weight: 800;
  letter-spacing: -0.055em;
  line-height: 0.93;
}

h2 {
  font-size: clamp(2rem, 4.5vw, 3.6rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 0.97;
}

h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

/* ===================================
   LAYOUT
   =================================== */

.page-shell {
  width: 100%;
  overflow-x: hidden;
}

.container {
  width: min(calc(100% - 48px), var(--max-width));
  margin: 0 auto;
}

/* ===================================
   HEADER
   =================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid transparent;
  transition: border-color 200ms ease, background-color 200ms ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line-strong);
  background: rgba(250, 250, 250, 0.96);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-top: 16px;
  padding-bottom: 16px;
}

.brand-lockup {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 30px;
  height: 30px;
  background: var(--ink);
  border-radius: 0px;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  font-size: 0;
}

.brand-mark::after {
  content: "TR";
  color: white;
  font-size: 0.6rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  font-family: "Inter", sans-serif;
}

.brand-mark span {
  display: none;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.brand-text strong {
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.brand-text span {
  font-size: 0.68rem;
  color: var(--muted);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  line-height: 1;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.top-nav a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
  transition: color 120ms ease;
}

.top-nav a:hover {
  color: var(--ink);
}

.lang-switch {
  display: flex;
  align-items: center;
  gap: 2px;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: 0px;
  padding: 3px;
}

.lang-switch a {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  padding: 5px 11px;
  border-radius: 0px;
  transition: all 120ms ease;
}

.lang-switch .active {
  background: var(--ink);
  color: white;
}

/* ===================================
   HERO
   =================================== */

.hero {
  padding: 80px 0 72px;
  border-bottom: 2px solid var(--ink);
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  align-items: start;
}

.hero-copy {
  max-width: 720px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 24px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.eyebrow::before {
  display: none;
}

.hero h1 {
  margin-bottom: 28px;
}

.lead {
  font-size: 1.0625rem;
  line-height: 1.68;
  color: var(--ink-2);
  max-width: 54ch;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 600;
  height: 44px;
  padding: 0 22px;
  border-radius: var(--radius);
  transition: all 140ms ease;
  cursor: pointer;
  border: 1px solid transparent;
  letter-spacing: 0.01em;
}

.button-primary {
  background: var(--ink);
  color: white;
  border-color: var(--ink);
}

.button-primary:hover {
  background: #2a2a30;
}

.button-secondary {
  background: transparent;
  color: var(--ink);
  border-color: var(--ink);
}

.button-secondary:hover {
  background: var(--ink);
  color: white;
  border-color: var(--ink);
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--ink-2);
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: 0px;
  padding: 5px 11px;
}

.tag::before {
  display: none;
}

/* Profile card */

.hero-card {
  display: flex;
  align-items: stretch;
}

.profile-card {
  width: 100%;
  padding: 28px;
  background: var(--surface-alt);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius-lg);
  position: sticky;
  top: 80px;
}

.profile-card .card-label {
  display: block;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
}

.profile-card h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: -0.03em;
  margin-bottom: 10px;
  line-height: 1.1;
}

.profile-card p {
  color: var(--ink-2);
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.profile-card dl {
  border-top: 1px solid var(--line-strong);
  padding-top: 16px;
  display: grid;
  gap: 12px;
}

.profile-card dt {
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 2px;
}

.profile-card dd {
  font-size: 0.9rem;
  color: var(--ink);
  margin: 0;
}

/* ===================================
   METRICS STRIP
   =================================== */

.metrics-strip {
  background: var(--surface-alt);
  padding: 48px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink);
}

.metrics-strip .container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.metric-item {
  padding: 0 40px 0 0;
  border-right: 1px solid var(--line-strong);
}

.metric-item:first-child {
  padding-left: 0;
}

.metric-item:last-child {
  border-right: none;
  padding-left: 40px;
  padding-right: 0;
}

.metric-item + .metric-item:not(:last-child) {
  padding-left: 40px;
}

.metric-value {
  display: block;
  font-size: 3.25rem;
  font-weight: 800;
  letter-spacing: -0.05em;
  line-height: 1;
  color: var(--ink);
  margin-bottom: 8px;
}

.metric-label {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ===================================
   SECTIONS
   =================================== */

.section {
  padding: 88px 0;
  border-bottom: 1px solid var(--line-strong);
}

.section-heading {
  margin-bottom: 48px;
}

.section-heading .eyebrow {
  margin-bottom: 14px;
}

.section-heading h2 {
  max-width: 14ch;
}

/* ===================================
   SERVICES
   =================================== */

.card-grid {
  display: grid;
  gap: 1px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
}

.card-grid.three-up {
  grid-template-columns: repeat(3, 1fr);
}

.content-card {
  background: var(--surface);
  padding: 36px 32px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.card-number {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--ink);
  line-height: 1;
}

.content-card h3 {
  font-size: 1.125rem;
}

.content-card p {
  font-size: 0.9rem;
  flex-grow: 1;
}

/* ===================================
   PROOF / TIMELINE
   =================================== */

.timeline {
  display: grid;
  gap: 1px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
}

.timeline-item {
  background: var(--surface);
  padding: 32px 36px;
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 28px;
  align-items: start;
}

.timeline-meta {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 2px;
}

.timeline-tag {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
}

.timeline-body h3 {
  margin-bottom: 8px;
}

.metrics-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 28px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  overflow: hidden;
}

.metrics-row > div {
  background: var(--surface-alt);
  padding: 22px 20px;
}

.metrics-row strong {
  display: block;
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1;
  color: var(--ink);
  margin-bottom: 6px;
}

.metrics-row span {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.45;
}

/* ===================================
   SPLIT LAYOUT (differentiators)
   =================================== */

.split-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
}

.split-dark {
  background: var(--bg-dark);
  padding: 48px 40px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 32px;
}

.split-dark h2 {
  color: white;
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  max-width: 13ch;
}

.split-dark-kicker {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.3);
}

.split-light {
  background: var(--surface-alt);
  padding: 48px 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 20px;
}

.split-light > p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 8px;
}

.bullet-panel {
  display: grid;
  gap: 14px;
}

.bullet-panel li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 0.9375rem;
  color: var(--ink-2);
  line-height: 1.6;
}

.bullet-panel li::before {
  content: "•";
  font-weight: 700;
  color: var(--ink);
  flex-shrink: 0;
  font-size: 0.875rem;
  margin-top: 1px;
}

/* ===================================
   EXPERIENCE / ABOUT
   =================================== */

.experience-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 24px;
}

.experience-card {
  background: var(--surface);
  padding: 32px 28px;
}

.role-meta {
  display: block;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 10px;
}

.experience-card h3 {
  margin-bottom: 8px;
}

.publication-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 0;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  align-items: baseline;
}

.publication-strip span {
  font-size: 0.8125rem;
  color: var(--muted);
}

.publication-strip span:first-child {
  font-weight: 700;
  color: var(--ink);
  margin-right: 6px;
}

.publication-strip a {
  color: var(--ink-2);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--line-strong);
  transition: color 120ms ease;
}

.publication-strip a:hover {
  color: var(--ink);
}

.publication-strip span:not(:first-child):not(:nth-child(2))::before {
  content: " · ";
  color: var(--line);
  margin: 0 4px;
}

/* ===================================
   CERT GRID
   =================================== */

.cert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--line-strong);
  border: 1.5px solid var(--ink);
  margin-top: 20px;
  overflow: hidden;
}

.cert-item {
  background: var(--surface-alt);
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.cert-num {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  color: var(--ink);
  line-height: 1;
}

.cert-name {
  font-size: 0.8125rem;
  color: var(--ink-2);
  line-height: 1.45;
}

/* ===================================
   FAQ
   =================================== */

.faq-list {
  border: 1.5px solid var(--ink);
  border-radius: var(--radius);
  overflow: hidden;
  display: grid;
  gap: 0;
}

.faq-list details {
  background: var(--surface);
  border-bottom: 1px solid var(--line-strong);
}

.faq-list details:last-child {
  border-bottom: none;
}

.faq-list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 28px;
  cursor: pointer;
  list-style: none;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.01em;
  user-select: none;
  transition: background 120ms ease;
}

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

.faq-list summary:hover {
  background: var(--surface-soft);
}

.faq-list summary::after {
  content: "+";
  font-size: 1.375rem;
  font-weight: 400;
  color: var(--ink);
  flex-shrink: 0;
  line-height: 1;
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list details p {
  padding: 18px 28px 22px;
  border-top: 1px solid var(--line);
  background: var(--surface-soft);
  color: var(--ink-2);
  font-size: 0.9375rem;
  line-height: 1.7;
  margin: 0;
}

/* ===================================
   CONTACT
   =================================== */

.contact-panel {
  background: var(--bg-dark);
  padding: 88px 0;
  border-bottom: none;
}

.contact-panel .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}

.contact-panel .section-heading {
  margin-bottom: 0;
}

.contact-panel .eyebrow {
  color: rgba(255, 255, 255, 0.4);
}

.contact-panel h2 {
  color: white;
  max-width: 12ch;
}

.contact-details {
  display: grid;
  gap: 12px;
}

.contact-details a {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 18px 22px;
  border: 1px solid rgba(255, 255, 255, 0.09);
  border-radius: var(--radius);
  color: white;
  font-size: 0.9375rem;
  font-weight: 500;
  transition: border-color 140ms ease, background 140ms ease;
}

.contact-details a:hover {
  border-color: rgba(255, 255, 255, 0.22);
  background: rgba(255, 255, 255, 0.04);
}

.contact-icon {
  width: 34px;
  height: 34px;
  border-radius: 0px;
  background: rgba(255, 255, 255, 0.07);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  font-size: 0.9rem;
  font-style: normal;
  font-weight: 600;
}

/* ===================================
   FOOTER
   =================================== */

.site-footer {
  padding: 20px 0;
  border-top: 1px solid var(--line);
  background: var(--bg);
}

.site-footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.site-footer p {
  font-size: 0.8125rem;
  color: var(--muted);
  margin: 0;
}

/* ===================================
   REVEAL ANIMATION
   =================================== */

[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 600ms cubic-bezier(0.16, 1, 0.3, 1),
              transform 600ms cubic-bezier(0.16, 1, 0.3, 1);
}

.is-visible {
  opacity: 1 !important;
  transform: none !important;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: none; }
}

/* ===================================
   JAPANESE FONT OVERRIDE
   =================================== */

html[lang="ja-JP"],
html[lang="ja-JP"] * {
  font-family: "Noto Sans JP", sans-serif !important;
}

html[lang="ja-JP"] h1,
html[lang="ja-JP"] h2,
html[lang="ja-JP"] h3 {
  letter-spacing: -0.02em;
}

/* ===================================
   RESPONSIVE — tablet
   =================================== */

/* ===================================
   RESPONSIVE — wide (1280+): hero column balance
   =================================== */

@media (min-width: 1280px) {
  .hero .container {
    grid-template-columns: 1fr 340px;
  }
}

/* ===================================
   RESPONSIVE — tablet (980px and below)
   =================================== */

@media (max-width: 980px) {
  .hero .container {
    grid-template-columns: 1fr;
  }

  .hero-copy {
    max-width: 640px;
  }

  .profile-card {
    position: static;
    max-width: 480px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .timeline-meta {
    padding-top: 0;
  }

  .split-layout {
    grid-template-columns: 1fr;
  }

  .split-dark {
    min-height: auto;
    padding: 40px 36px;
  }

  .split-light {
    padding: 40px 36px;
  }

  .contact-panel .container {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .card-grid.three-up {
    grid-template-columns: 1fr 1fr;
  }

  /* last card spans full width when 3 cards in 2-col grid */
  .card-grid.three-up .content-card:last-child {
    grid-column: 1 / -1;
  }

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

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

  .metrics-strip .container {
    grid-template-columns: 1fr;
  }

  .metric-item {
    padding: 0 0 28px;
    border-right: none;
    border-bottom: 1px solid var(--line-strong);
  }

  .metric-item:last-child {
    padding-left: 0;
    border-bottom: none;
    padding-bottom: 0;
  }

  .metric-item + .metric-item:not(:last-child) {
    padding-left: 0;
  }

  .metrics-row {
    grid-template-columns: 1fr 1fr;
  }

  .metrics-row > div:last-child {
    grid-column: 1 / -1;
  }

  .site-header .container {
    flex-wrap: wrap;
    row-gap: 10px;
  }

  .brand-lockup {
    flex: 1;
  }

  .top-nav {
    order: 3;
    width: 100%;
    gap: 20px;
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }

  .top-nav::-webkit-scrollbar {
    display: none;
  }

  .section {
    padding: 72px 0;
  }
}

/* ===================================
   RESPONSIVE — mobile (640px and below)
   =================================== */

@media (max-width: 640px) {
  .container {
    width: min(calc(100% - 28px), var(--max-width));
  }

  .hero {
    padding: 44px 0 36px;
  }

  h1 {
    font-size: clamp(2.6rem, 12vw, 4.2rem);
  }

  h2 {
    font-size: clamp(1.7rem, 7.5vw, 2.6rem);
  }

  .section {
    padding: 52px 0;
  }

  .section-heading {
    margin-bottom: 32px;
  }

  .content-card {
    padding: 24px 22px;
  }

  .experience-card {
    padding: 24px 22px;
  }

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

  .timeline-item {
    padding: 24px 22px;
  }

  .split-dark,
  .split-light {
    padding: 32px 24px;
  }

  .contact-panel {
    padding: 52px 0;
  }

  .card-grid.three-up {
    grid-template-columns: 1fr;
  }

  .card-grid.three-up .content-card:last-child {
    grid-column: auto;
  }

  .metrics-row {
    grid-template-columns: 1fr;
  }

  .metrics-row > div:last-child {
    grid-column: auto;
  }

  .hero-actions {
    flex-direction: column;
  }

  .button {
    width: 100%;
    justify-content: center;
  }

  .lang-switch {
    margin-left: auto;
  }

  .metrics-strip {
    padding: 36px 0;
  }

  .metric-value {
    font-size: 2.6rem;
  }

  .site-footer .container {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .faq-list summary {
    padding: 18px 22px;
    font-size: 0.9rem;
  }

  .faq-list details p {
    padding: 14px 22px 18px;
  }
}

/* ===================================
   REDUCED MOTION
   =================================== */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
}