/* =========================================================
   Yutaka Portfolio — Stylesheet
   Sections: Reset / Variables / Base / Utilities / Header
   Hero / Solutions / Works / Philosophy / Foundation / Flow / AI
   Message / Contact / Footer / Animations / Media Queries
   ========================================================= */

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body, h1, h2, h3, h4, p, ul, ol, dl, dd, figure, blockquote { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}

/* ---------- Variables ---------- */
:root {
  --ink: #0a0a0b;
  --ink-soft: #18181b;
  --paper: #ffffff;
  --paper-soft: #f7f7f8;
  --text: #18181b;
  --text-muted: #56565f;
  --text-faint: #9a9aa2;
  --border: #e7e7ea;
  --border-soft: #f0f0f2;

  --accent-1: #4f46e5;
  --accent-2: #7c3aed;
  --accent-grad: linear-gradient(135deg, var(--accent-1) 0%, var(--accent-2) 100%);
  --accent-soft-bg: #f2f1fd;

  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 28px;

  --ease: cubic-bezier(.16, 1, .3, 1);
  --container: 1180px;

  --fs-hero: clamp(2.4rem, 6vw + 0.5rem, 5rem);
  --fs-h2: clamp(1.9rem, 3.4vw + 0.4rem, 3rem);
  --fs-lead: clamp(1.05rem, 1vw + 0.6rem, 1.25rem);
}

/* ---------- Base ---------- */
body {
  font-family: "Inter", "Noto Sans JP", -apple-system, BlinkMacSystemFont,
    "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", sans-serif;
  color: var(--text);
  background: var(--paper);
  line-height: 1.7;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: #fff;
  padding: 12px 20px;
  border-radius: 0 0 8px 0;
  z-index: 999;
}
.skip-link:focus { left: 0; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.section { padding: clamp(80px, 12vw, 160px) 0; }
.section-alt { background: var(--paper-soft); }

.section-eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--accent-1);
  margin-bottom: 16px;
}

.section-title {
  font-size: var(--fs-h2);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.35;
  max-width: 18ch;
}

.section-lead {
  margin-top: 20px;
  font-size: var(--fs-lead);
  color: var(--text-muted);
  max-width: 56ch;
}

.br-mobile { display: inline; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 15px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.98rem;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease), color 0.3s var(--ease);
  white-space: nowrap;
}
.btn svg { transition: transform 0.3s var(--ease); }
.btn:hover svg { transform: translateX(3px); }

.btn-primary {
  background: var(--ink);
  color: #fff;
  box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 24px -8px rgba(0,0,0,0.35); }

.btn-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--paper-soft); transform: translateY(-2px); }

/* ---------- Reveal animation ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Header ---------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 20px 0;
  color: #fff;
  transition: background 0.4s var(--ease), box-shadow 0.4s var(--ease), padding 0.4s var(--ease), color 0.4s var(--ease);
}
.site-header.is-scrolled {
  padding: 14px 0;
  background: rgba(255,255,255,0.8);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  box-shadow: 0 1px 0 rgba(0,0,0,0.06);
  color: var(--ink);
}

.nav-container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 32px;
  font-size: 0.92rem;
  font-weight: 500;
}
.nav-desktop a:not(.nav-cta) {
  color: rgba(255,255,255,0.75);
  position: relative;
  transition: color 0.25s var(--ease);
}
.nav-desktop a:not(.nav-cta):hover { color: #fff; }
.site-header.is-scrolled .nav-desktop a:not(.nav-cta) { color: var(--text-muted); }
.site-header.is-scrolled .nav-desktop a:not(.nav-cta):hover { color: var(--ink); }
.nav-desktop a:not(.nav-cta)::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -4px;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s var(--ease);
}
.nav-desktop a:not(.nav-cta):hover::after { transform: scaleX(1); transform-origin: left; }

.nav-cta {
  background: #fff;
  color: var(--ink) !important;
  padding: 10px 20px;
  border-radius: 999px;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease), color 0.25s var(--ease);
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 8px 16px -6px rgba(0,0,0,0.25); }
.site-header.is-scrolled .nav-cta { background: var(--ink); color: #fff !important; }
.site-header.is-scrolled .nav-cta:hover { box-shadow: 0 8px 16px -6px rgba(0,0,0,0.35); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: #fff;
  transition: transform 0.3s var(--ease), opacity 0.3s var(--ease), background 0.3s var(--ease);
  margin: 0 auto;
}
.site-header.is-scrolled .nav-toggle span { background: var(--ink); }
.nav-toggle[aria-expanded="true"] span { background: var(--ink); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

.nav-mobile {
  display: none;
  position: fixed;
  inset: 0;
  top: 0;
  background: var(--paper);
  padding: 100px 32px 40px;
  flex-direction: column;
  gap: 4px;
  font-size: 1.4rem;
  font-weight: 600;
  transform: translateY(-8px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease);
  z-index: 90;
}
.nav-mobile.is-open {
  display: flex;
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.nav-mobile a { padding: 14px 0; border-bottom: 1px solid var(--border-soft); color: var(--ink); }
.nav-mobile a.nav-cta {
  margin-top: 20px;
  padding: 16px 0;
  text-align: center;
  border-bottom: none;
  background: var(--ink);
  color: #fff !important;
  border-radius: 999px;
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 140px 0 80px;
  background: var(--ink);
  color: #fff;
  overflow: hidden;
}

.hero-bg { position: absolute; inset: 0; z-index: 0; }
.hero-glow {
  position: absolute;
  inset: 0;
  display: block;
  filter: hue-rotate(0deg) saturate(1) brightness(1);
  transition: filter 1.6s ease;
}
.hero[data-theme="ugokasu"] .hero-glow { filter: hue-rotate(48deg) saturate(1.05) brightness(1); }
.hero[data-theme="sodateru"] .hero-glow { filter: hue-rotate(-62deg) saturate(1.15) brightness(1.04); }
.hero[data-theme="hirogeru"] .hero-glow { filter: hue-rotate(-30deg) saturate(1.1) brightness(1.03); }

.hero-glow .blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.55;
  will-change: transform;
}
.blob-1 { width: 520px; height: 520px; top: -160px; left: -120px; background: radial-gradient(circle, #3b82f6, transparent 70%); animation: float1 22s ease-in-out infinite; }
.blob-2 { width: 480px; height: 480px; bottom: -180px; right: -100px; background: radial-gradient(circle, #6366f1, transparent 70%); animation: float2 26s ease-in-out infinite; }
.blob-3 { width: 380px; height: 380px; top: 30%; left: 55%; background: radial-gradient(circle, #2563eb, transparent 70%); opacity: 0.35; animation: float3 30s ease-in-out infinite; }

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, black 30%, transparent 75%);
}

@keyframes float1 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(40px, 60px); } }
@keyframes float2 { 0%,100% { transform: translate(0,0); } 50% { transform: translate(-50px, -40px); } }
@keyframes float3 { 0%,100% { transform: translate(0,0) scale(1); } 50% { transform: translate(-30px, 30px) scale(1.1); } }

.hero-inner { position: relative; z-index: 1; }

.eyebrow {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: #c9c3ff;
  margin-bottom: 24px;
  transition-delay: 0.05s;
}

.hero-title {
  font-size: var(--fs-hero);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.3;
  max-width: 18ch;
  transition-delay: 0.1s;
}
.hero-title-visual { display: contents; }

/* Non-rotating words: kept quiet so the rotating word reads as the hero */
.hero-fixed {
  font-size: 0.74em;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.5);
  letter-spacing: -0.01em;
}

/* ---------- Word rotator ---------- */
.word-rotator {
  display: inline-grid;
  vertical-align: bottom;
  text-align: left;
  overflow: visible;
  padding: 0 0.04em;
}
.word-rotator-item {
  grid-area: 1 / 1;
  font-family: var(--wr-ff, "Noto Sans JP", "Inter", sans-serif);
  font-weight: var(--wr-w, 800);
  font-size: calc(1em * var(--wr-fs, 1.22));
  letter-spacing: var(--wr-ls, -0.02em);
  background: var(--wr-grad, linear-gradient(135deg, var(--accent-1), var(--accent-2)));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  white-space: nowrap;
  opacity: 0;
  transform: translate(var(--wr-x-in, 0), var(--wr-y-in, 10px)) scale(var(--wr-s-in, 0.94));
  transition:
    opacity 0.42s cubic-bezier(.16,1,.3,1),
    transform 0.46s cubic-bezier(.16,1,.3,1);
}
.word-rotator-item.is-active {
  opacity: 1;
  transform: translate(0, 0) scale(1);
}
.word-rotator-item.is-exiting {
  opacity: 0;
  transition-duration: 0.32s;
  transform: translate(var(--wr-x-out, 0), var(--wr-y-out, -8px)) scale(var(--wr-s-out, 1.03));
}

.word--tsutawaru {
  --wr-ff: "Noto Sans JP", "Inter", sans-serif;
  --wr-w: 800;
  --wr-ls: -0.02em;
  --wr-grad: linear-gradient(120deg, #3b82f6, #6366f1);
  --wr-y-in: 10px; --wr-y-out: -8px;
  --wr-s-in: 0.94; --wr-s-out: 1.03;
}
.word--ugokasu {
  --wr-ff: "Zen Kaku Gothic New", "Inter", sans-serif;
  --wr-w: 800;
  --wr-ls: -0.01em;
  --wr-grad: linear-gradient(120deg, #8b5cf6, #a855f7);
  --wr-x-in: -10px; --wr-x-out: 8px;
  --wr-y-in: 0; --wr-y-out: 0;
  --wr-s-in: 0.95; --wr-s-out: 1.03;
}
.word--sodateru {
  --wr-ff: "Shippori Mincho", serif;
  --wr-w: 800;
  --wr-fs: 1.26;
  --wr-ls: 0.01em;
  --wr-grad: linear-gradient(120deg, #10b981, #34d399);
  --wr-y-in: 10px; --wr-y-out: -8px;
  --wr-s-in: 0.94; --wr-s-out: 1.03;
}
.word--hirogeru {
  --wr-ff: "Zen Maru Gothic", "Inter", sans-serif;
  --wr-w: 800;
  --wr-ls: -0.01em;
  --wr-grad: linear-gradient(120deg, #06b6d4, #22d3ee);
  --wr-y-in: 10px; --wr-y-out: -8px;
  --wr-s-in: 0.95; --wr-s-out: 1.04;
}

@media (prefers-reduced-motion: reduce) {
  .word-rotator-item { transition: none !important; }
}

.hero-lead {
  margin-top: 32px;
  font-size: var(--fs-lead);
  color: rgba(255,255,255,0.72);
  max-width: 46ch;
  transition-delay: 0.18s;
}

.hero-actions {
  margin-top: 52px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  transition-delay: 0.26s;
}
.hero .btn-primary { background: #fff; color: var(--ink); }
.hero .btn-primary:hover { box-shadow: 0 12px 28px -8px rgba(255,255,255,0.35); }
.hero .btn-secondary { color: #fff; border-color: rgba(255,255,255,0.3); }
.hero .btn-secondary:hover { background: rgba(255,255,255,0.08); }

.scroll-cue {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  z-index: 1;
  color: rgba(255,255,255,0.5);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
}
.scroll-cue span {
  width: 1px; height: 32px;
  background: linear-gradient(rgba(255,255,255,0.7), transparent);
  animation: scrollcue 2s ease-in-out infinite;
}
@keyframes scrollcue { 0% { transform: scaleY(0); transform-origin: top; opacity: 0.4; } 50% { transform: scaleY(1); transform-origin: top; opacity: 1; } 51% { transform-origin: bottom; } 100% { transform: scaleY(0); transform-origin: bottom; opacity: 0.4; } }

/* ---------- Solutions ---------- */
.solutions-grid {
  margin-top: 64px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}
.solution-card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
}
.solution-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px -20px rgba(20,20,30,0.18);
  border-color: transparent;
}
.solution-card-wide { grid-column: span 2; display: flex; align-items: flex-start; gap: 28px; }
.solution-card-wide h3 { min-width: 220px; }

.solution-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px; height: 48px;
  border-radius: 14px;
  background: var(--accent-soft-bg);
  color: var(--accent-1);
  margin-bottom: 24px;
}
.solution-icon svg { width: 24px; height: 24px; }

.solution-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}
.solution-card p { color: var(--text-muted); font-size: 0.96rem; }

/* ---------- Works ---------- */
.works-list {
  margin-top: 64px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}
.work-card {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: 0;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: box-shadow 0.4s var(--ease), transform 0.4s var(--ease);
}
.work-card:hover { box-shadow: 0 30px 60px -30px rgba(20,20,30,0.25); transform: translateY(-3px); }
.work-card:nth-child(even) { grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); }
.work-card:nth-child(even) .work-visual { order: 2; }
.work-card:nth-child(even) .work-body { order: 1; }

.work-visual {
  position: relative;
  min-height: 280px;
  display: block;
  overflow: hidden;
}
.mockup-chrome {
  position: absolute;
  top: 20px; left: 20px;
  display: flex; gap: 6px;
  z-index: 2;
}
.mockup-chrome i { width: 9px; height: 9px; border-radius: 50%; background: rgba(255,255,255,0.5); }

.mockup-mark {
  position: absolute;
  right: 8%;
  bottom: -6%;
  font-size: 9rem;
  font-weight: 800;
  color: rgba(255,255,255,0.16);
  line-height: 1;
  letter-spacing: -0.05em;
  z-index: 1;
}

.mockup-lines { position: absolute; left: 32px; bottom: 32px; display: flex; flex-direction: column; gap: 8px; z-index: 2; }
.mockup-lines i { display: block; height: 6px; border-radius: 3px; background: rgba(255,255,255,0.55); }
.mockup-lines i:nth-child(1) { width: 120px; }
.mockup-lines i:nth-child(2) { width: 160px; }
.mockup-lines i:nth-child(3) { width: 90px; }

.mockup-dots { position: absolute; left: 32px; bottom: 32px; display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; z-index: 2; }
.mockup-dots i { width: 34px; height: 34px; border-radius: 10px; background: rgba(255,255,255,0.22); }

.mockup-glow { position: absolute; inset: 0; background: radial-gradient(circle at 70% 70%, rgba(255,80,220,0.4), transparent 60%); z-index: 1; }

.mockup-frames { position: absolute; left: 32px; bottom: 32px; display: flex; gap: 10px; z-index: 2; }
.mockup-frames i { width: 64px; height: 44px; border: 1.5px solid rgba(255,255,255,0.4); border-radius: 8px; }

.mockup-grid-icon { position: absolute; left: 32px; bottom: 32px; display: grid; grid-template-columns: repeat(2,1fr); gap: 8px; z-index: 2; }
.mockup-grid-icon i { width: 30px; height: 30px; border-radius: 8px; background: rgba(255,255,255,0.5); }

.mockup-stella { background: linear-gradient(135deg,#1c4e80,#38b6b0); }
.mockup-mwork { background: linear-gradient(135deg,#ff9472,#f2709c); }
.mockup-dsui { background: linear-gradient(135deg,#1a0b2e,#5b1a8f 60%,#b81ea0); }
.mockup-opreien { background: linear-gradient(135deg,#3a3f52,#6b7290); }
.mockup-other { background: linear-gradient(135deg,#3f3f46,#6d6d78); }

.work-body {
  padding: 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.work-body h3 { font-size: 1.4rem; font-weight: 800; letter-spacing: -0.01em; margin-bottom: 16px; }
.work-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.work-tags li {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent-1);
  background: var(--accent-soft-bg);
  padding: 6px 12px;
  border-radius: 999px;
}
.work-body p { color: var(--text-muted); font-size: 0.96rem; margin-bottom: 22px; }

.work-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-weight: 700;
  font-size: 0.92rem;
  width: fit-content;
  border-bottom: 1.5px solid var(--ink);
  padding-bottom: 2px;
  transition: gap 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.work-link:hover { gap: 10px; color: var(--accent-1); border-color: var(--accent-1); }

.work-card-other .work-visual { pointer-events: none; }

/* ---------- Philosophy ---------- */
.philosophy { background: var(--paper-soft); }
.philosophy-inner { max-width: 880px; text-align: center; margin: 0 auto; }
.philosophy .section-eyebrow { justify-self: center; }
.philosophy-quote {
  font-size: clamp(1.6rem, 3.2vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.5;
  margin-bottom: 40px;
}
.philosophy-body {
  font-size: clamp(1.05rem, 1.4vw, 1.25rem);
  color: var(--text-muted);
  line-height: 2;
  margin-bottom: 28px;
}
.philosophy-sub {
  font-size: 1rem;
  color: var(--text-faint);
  line-height: 1.9;
}

/* ---------- Foundation ---------- */
.foundation-layout {
  margin-top: 64px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 320px);
  gap: 20px;
  align-items: start;
}
.foundation-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}
.foundation-card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 28px 26px;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.foundation-card:hover { transform: translateY(-4px); box-shadow: 0 20px 40px -20px rgba(20,20,30,0.18); }
.foundation-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;
  border-radius: 12px;
  background: var(--accent-soft-bg);
  color: var(--accent-1);
  margin-bottom: 18px;
}
.foundation-icon svg { width: 22px; height: 22px; }
.foundation-card h3 {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
}
.foundation-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.foundation-tags li {
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 5px 10px;
  border-radius: 999px;
}

.certificate-card {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: 100%;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: left;
  cursor: pointer;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease), border-color 0.35s var(--ease);
}
.certificate-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 20px 40px -20px rgba(20,20,30,0.18);
  border-color: transparent;
}
.certificate-thumb {
  display: block;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border-soft);
  background: var(--paper-soft);
  aspect-ratio: 4 / 3;
}
.certificate-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
.certificate-meta { display: flex; flex-direction: column; gap: 4px; }
.certificate-hours { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.01em; }
.certificate-course { font-size: 0.85rem; color: var(--text-muted); }
.certificate-cta {
  margin-top: 10px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-1);
}
.certificate-card:hover .certificate-cta svg { transform: translateX(3px); }
.certificate-cta svg { transition: transform 0.3s var(--ease); }

/* ---------- Flow (thinking process) ---------- */
.thinking-list {
  margin-top: 80px;
  position: relative;
}
.thinking-item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(90px, 160px) minmax(0, 1fr);
  align-items: start;
  column-gap: clamp(24px, 4vw, 56px);
  padding: 44px 0;
  border-top: 1px solid var(--border-soft);
}
.thinking-item:last-child { padding-bottom: 0; }

.thinking-num {
  display: block;
  font-family: "Inter", sans-serif;
  font-size: clamp(3.2rem, 6vw, 4.6rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
  position: relative;
  z-index: 1;
}

.thinking-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px; height: 40px;
  border-radius: 11px;
  background: var(--accent-soft-bg);
  color: var(--accent-1);
  margin-bottom: 20px;
}
.thinking-icon svg { width: 20px; height: 20px; }

.thinking-content h3 {
  font-size: clamp(1.2rem, 1.6vw, 1.5rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 14px;
}
.thinking-content p {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.85;
  max-width: 52ch;
}

/* ---------- AI ---------- */
.ai-grid {
  margin-top: 64px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0,1fr));
  gap: 20px;
}
.ai-card {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 32px 26px;
  transition: transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
}
.ai-card:hover { transform: translateY(-4px); box-shadow: 0 20px 40px -20px rgba(20,20,30,0.18); }
.ai-phase {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-1);
  letter-spacing: 0.04em;
  margin-bottom: 16px;
}
.ai-tools { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.tool-badge {
  font-size: 0.82rem;
  font-weight: 700;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
}
.ai-card p { font-size: 0.92rem; color: var(--text-muted); }

/* ---------- Message ---------- */
.message-section {
  background: var(--ink);
  color: #fff;
  text-align: center;
}
.message-inner { max-width: 880px; margin: 0 auto; }
.message-pre {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.55);
  margin-bottom: 28px;
  letter-spacing: 0.02em;
}
.message-main {
  font-size: clamp(2rem, 5vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.4;
  margin-bottom: 36px;
}
.message-post {
  font-size: clamp(1rem, 1.4vw, 1.2rem);
  color: rgba(255,255,255,0.65);
}

/* ---------- Contact ---------- */
.contact-inner { text-align: center; }
.contact-inner .section-title { max-width: none; }
.contact-grid {
  margin-top: 56px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0,1fr));
  gap: 20px;
  text-align: left;
}
.contact-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
  padding: 32px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), border-color 0.3s var(--ease);
}
.contact-card:hover { transform: translateY(-4px); box-shadow: 0 20px 40px -20px rgba(20,20,30,0.18); border-color: transparent; }
.contact-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px;
  border-radius: 12px;
  background: var(--accent-soft-bg);
  color: var(--accent-1);
}
.contact-icon svg { width: 22px; height: 22px; }
.contact-label { font-size: 0.8rem; font-weight: 700; color: var(--text-faint); letter-spacing: 0.04em; }
.contact-value { font-size: 1.05rem; font-weight: 700; word-break: break-all; }

.contact-note { margin-top: 32px; font-size: 0.86rem; color: var(--text-faint); text-align: center; }

/* ---------- Footer ---------- */
.site-footer { background: var(--paper-soft); border-top: 1px solid var(--border); padding: 56px 0 40px; }
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
}
.footer-logo { font-weight: 800; font-size: 1.1rem; margin-bottom: 6px; }
.footer-role { font-size: 0.8rem; color: var(--text-faint); }
.footer-nav { display: flex; gap: 24px; flex-wrap: wrap; font-size: 0.88rem; color: var(--text-muted); }
.footer-nav a:hover { color: var(--ink); }
.footer-copy { font-size: 0.8rem; color: var(--text-faint); width: 100%; text-align: center; order: 3; margin-top: 12px; }

@media (min-width: 640px) {
  .footer-copy { width: auto; order: 0; margin-top: 0; text-align: right; }
}

/* =========================================================
   Media Queries
   ========================================================= */
@media (max-width: 980px) {
  .nav-desktop { display: none; }
  .nav-toggle { display: flex; }

  .solutions-grid { grid-template-columns: 1fr; }
  .solution-card-wide { grid-column: span 1; flex-direction: column; }

  .work-card, .work-card:nth-child(even) { grid-template-columns: 1fr; }
  .work-card .work-visual, .work-card:nth-child(even) .work-visual { order: 1 !important; min-height: 220px; }
  .work-card .work-body, .work-card:nth-child(even) .work-body { order: 2 !important; }

  .thinking-item { grid-template-columns: 72px minmax(0, 1fr); column-gap: 24px; padding: 36px 0; }

  .ai-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }

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

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

@media (max-width: 640px) {
  .br-mobile { display: block; }
  .section { padding: 72px 0; }
  .hero { padding-top: 120px; }
  .ai-grid { grid-template-columns: 1fr; }
  .work-body { padding: 28px; }
  .mockup-mark { font-size: 6rem; }
  .foundation-grid { grid-template-columns: 1fr; }

  .thinking-item { grid-template-columns: 1fr; row-gap: 16px; }
  .thinking-num { font-size: 2.4rem; }
}