:root[data-theme="dark"] {
  --bg-base: #0b0c10;
  --bg-deep: #07080b;
  --surface: rgba(20,21,27,0.66);
  --surface-hi: rgba(28,30,38,0.82);
  --ink: #ecebe6;
  --muted: #a3a29b;
  --faint: #6f6e67;
  --line: rgba(236,235,230,0.10);
  --line-hi: rgba(236,235,230,0.20);
  --accent: #7fd1ae;
  --accent-dim: rgba(127,209,174,0.16);
  --glow: rgba(127,209,174,0.10);
  --aura: rgba(127,209,174,0.10);
  --aura-2: rgba(90,130,200,0.07);
  --grid-line: rgba(236,235,230,0.030);
  --nav-fade-a: rgba(11,12,16,0.55);
  --nav-fade-b: rgba(11,12,16,0);
  --card-shadow: 0 1px 0 rgba(236,235,230,0.03);
  --card-shadow-hi: 0 10px 36px rgba(0,0,0,0.42);
  --noise-opacity: 0.022;
  --vignette: rgba(0,0,0,0.45);
}
:root[data-theme="light"] {
  --bg-base: #f3f1ea;
  --bg-deep: #e9e6dc;
  --surface: rgba(251,250,246,0.70);
  --surface-hi: rgba(255,255,255,0.88);
  --ink: #1f1e1a;
  --muted: #5f5d55;
  --faint: #8d8b81;
  --line: rgba(31,30,26,0.12);
  --line-hi: rgba(31,30,26,0.22);
  --accent: #1f6647;
  --accent-dim: rgba(31,102,71,0.10);
  --glow: rgba(31,102,71,0.08);
  --aura: rgba(31,102,71,0.07);
  --aura-2: rgba(120,150,110,0.06);
  --grid-line: rgba(31,30,26,0.035);
  --nav-fade-a: rgba(243,241,234,0.55);
  --nav-fade-b: rgba(243,241,234,0);
  --card-shadow: 0 1px 2px rgba(31,30,26,0.05), 0 4px 16px rgba(31,30,26,0.05);
  --card-shadow-hi: 0 6px 16px rgba(31,30,26,0.10), 0 22px 50px rgba(31,30,26,0.12);
  --noise-opacity: 0.045;
  --vignette: rgba(120,110,90,0.10);
}
:root {
  --serif: 'Newsreader', Georgia, serif;
  --sans: 'Noto Sans JP', system-ui, sans-serif;
  --mono: 'JetBrains Mono', monospace;
  /* sun: position + tint, the only thing time touches */
  --sun-x: 50%; --sun-y: 16%;
  --sun-core: rgba(255,250,235,0.55);
  --sun-halo: rgba(255,230,180,0.18);
  --sun-size: 220px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  color: var(--ink);
  font-family: var(--sans);
  font-weight: 300;
  font-feature-settings: "palt";
  -webkit-font-smoothing: antialiased;
  line-height: 1.9;
  overflow-x: hidden;
  transition: color 0.7s ease;
}

/* ===== BACKGROUND STACK ===== */
/* L0 base color */
.bg-base {
  position: fixed; inset: 0; z-index: -6;
  background: radial-gradient(140% 120% at 50% 0%, var(--bg-base) 0%, var(--bg-deep) 100%);
  transition: background 1.4s ease;
}
/* L1 brand aura — the "designed" glow that owns the palette */
.bg-aura {
  position: fixed; inset: -10%; z-index: -5; pointer-events: none;
  background:
    radial-gradient(50% 42% at 22% 18%, var(--aura) 0%, transparent 62%),
    radial-gradient(46% 40% at 84% 72%, var(--aura-2) 0%, transparent 60%);
  filter: blur(8px);
  transition: background 1.4s ease;
  animation: drift 28s ease-in-out infinite alternate;
}
@keyframes drift {
  0%   { transform: translate(0,0) scale(1); }
  100% { transform: translate(-2.5%, 1.8%) scale(1.05); }
}
/* L2 the sun — a single soft luminous body that time moves */
.sun {
  position: fixed; left: var(--sun-x); top: var(--sun-y); z-index: -4;
  width: var(--sun-size); height: var(--sun-size);
  transform: translate(-50%,-50%);
  pointer-events: none;
  background: radial-gradient(circle, var(--sun-core) 0%, var(--sun-halo) 34%, transparent 70%);
  transition: left 2s cubic-bezier(0.4,0,0.2,1), top 2s cubic-bezier(0.4,0,0.2,1), background 2s ease, width 2s ease, height 2s ease;
}
.sun::after {
  content: ""; position: absolute; inset: 38%;
  border-radius: 50%;
  background: var(--sun-core);
  filter: blur(6px);
}
/* L3 fine grid — barely-there structure */
.bg-grid {
  position: fixed; inset: 0; z-index: -3; pointer-events: none;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(120% 100% at 50% 30%, #000 30%, transparent 78%);
  -webkit-mask-image: radial-gradient(120% 100% at 50% 30%, #000 30%, transparent 78%);
  transition: background-image 1.4s ease;
}
/* L4 grain */
.bg-noise {
  position: fixed; inset: 0; z-index: -2; pointer-events: none; opacity: var(--noise-opacity);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  transition: opacity 0.7s ease;
}
/* L5 vignette to seat content */
.bg-vignette {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background: radial-gradient(130% 110% at 50% 38%, transparent 52%, var(--vignette) 100%);
  transition: background 1.4s ease;
}

.wrap { position: relative; z-index: 2; max-width: 860px; margin: 0 auto; padding: 0 2.5rem; }

/* progressive blur header — fixed full-width layer with stacked, masked blur tiers */
.header-blur { position: fixed; top: 0; left: 0; right: 0; height: 96px; z-index: 19; pointer-events: none; }
.header-blur::before { content: ""; position: absolute; inset: 0; background: linear-gradient(to bottom, var(--nav-fade-a), var(--nav-fade-b)); }
.header-blur .layer { position: absolute; inset: 0; }
.header-blur .l1 { backdrop-filter: blur(1px); -webkit-backdrop-filter: blur(1px); mask: linear-gradient(to bottom, #000 0%, #000 12.5%, transparent 25%); -webkit-mask: linear-gradient(to bottom, #000 0%, #000 12.5%, transparent 25%); }
.header-blur .l2 { backdrop-filter: blur(2px); -webkit-backdrop-filter: blur(2px); mask: linear-gradient(to bottom, #000 12.5%, #000 25%, transparent 37.5%); -webkit-mask: linear-gradient(to bottom, #000 12.5%, #000 25%, transparent 37.5%); }
.header-blur .l3 { backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); mask: linear-gradient(to bottom, transparent 12.5%, #000 25%, #000 37.5%, transparent 50%); -webkit-mask: linear-gradient(to bottom, transparent 12.5%, #000 25%, #000 37.5%, transparent 50%); }
.header-blur .l4 { backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); mask: linear-gradient(to bottom, transparent 25%, #000 37.5%, #000 50%, transparent 62.5%); -webkit-mask: linear-gradient(to bottom, transparent 25%, #000 37.5%, #000 50%, transparent 62.5%); }
.header-blur .l5 { backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); mask: linear-gradient(to bottom, transparent 37.5%, #000 56%, #000 70%, transparent 100%); -webkit-mask: linear-gradient(to bottom, transparent 37.5%, #000 56%, #000 70%, transparent 100%); }
.navbar { position: fixed; top: 0; left: 0; right: 0; z-index: 30; }
nav { display: flex; justify-content: space-between; align-items: center; padding: 1.5rem 2.5rem; max-width: 860px; margin: 0 auto; }
.logo { font-family: var(--serif); font-size: 18px; font-weight: 500; letter-spacing: 0.01em; }
.logo .bracket { color: var(--accent); }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-meta { font-family: var(--mono); font-size: 11px; color: var(--faint); letter-spacing: 0.04em; display: flex; align-items: center; gap: 8px; }
.nav-meta .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 8px var(--accent); animation: pulse 2.6s ease-in-out infinite; }
@keyframes pulse { 0%,100%{opacity:1;} 50%{opacity:0.35;} }
.timepill { font-family: var(--mono); font-size: 11px; color: var(--faint); letter-spacing: 0.04em; border: 1px solid var(--line-hi); border-radius: 100px; padding: 5px 12px; cursor: pointer; transition: all 0.25s ease; display: flex; align-items: center; gap: 7px; }
.timepill:hover { color: var(--accent); border-color: var(--accent-dim); background: var(--accent-dim); }
.timepill .sun-ico { font-size: 12px; }

.hero { padding: 8.5rem 0 6rem; }
.hero .tag { font-family: var(--mono); font-size: 12px; color: var(--accent); letter-spacing: 0.14em; margin-bottom: 2.25rem; display: inline-flex; align-items: center; gap: 10px; }
.hero .tag::before { content: ""; width: 28px; height: 1px; background: var(--accent); display: inline-block; }
.hero h1 { font-family: var(--serif); font-weight: 400; font-size: clamp(38px, 8vw, 76px); line-height: 1.18; letter-spacing: 0.005em; margin-bottom: 2.5rem; }
.hero h1 em { font-style: italic; color: var(--accent); }
.hero .lead { font-size: 16px; color: var(--muted); max-width: 44ch; font-weight: 300; }

/* time panel (collapsible) */
.timepanel { margin-top: 3.25rem; max-width: 460px; overflow: hidden; max-height: 0; opacity: 0; transition: max-height 0.5s ease, opacity 0.4s ease, margin 0.4s ease; }
.timepanel.open { max-height: 220px; opacity: 1; }
.timepanel-inner { padding: 1.4rem 1.7rem; border: 1px solid var(--line); border-radius: 16px; background: var(--surface); backdrop-filter: blur(12px); box-shadow: var(--card-shadow); }
.tp-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.tp-label { font-family: var(--mono); font-size: 11px; color: var(--faint); letter-spacing: 0.08em; text-transform: uppercase; }
.tp-phase { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: 0.05em; }
.time-slider { -webkit-appearance: none; appearance: none; width: 100%; height: 3px; border-radius: 3px; background: var(--line-hi); outline: none; cursor: pointer; margin: 0.4rem 0; }
.time-slider::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 16px; height: 16px; border-radius: 50%; background: var(--accent); cursor: pointer; box-shadow: 0 0 12px var(--glow); border: 2px solid var(--surface-hi); transition: transform 0.15s ease; }
.time-slider::-webkit-slider-thumb:hover { transform: scale(1.2); }
.time-slider::-moz-range-thumb { width: 16px; height: 16px; border-radius: 50%; background: var(--accent); cursor: pointer; border: 2px solid var(--surface-hi); }
.time-ticks { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 9.5px; color: var(--faint); margin-top: 5px; }
.tp-foot { display: flex; justify-content: space-between; align-items: center; margin-top: 1rem; }
.tp-mode { font-family: var(--mono); font-size: 10.5px; color: var(--faint); }
.reset-btn { font-family: var(--mono); font-size: 10.5px; color: var(--muted); background: transparent; border: 1px solid var(--line-hi); border-radius: 100px; padding: 4px 12px; cursor: pointer; transition: all 0.25s ease; }
.reset-btn:hover { color: var(--accent); border-color: var(--accent-dim); background: var(--accent-dim); }

section { padding: 5rem 0; border-top: 1px solid var(--line); }
.sec-head { display: flex; align-items: baseline; gap: 16px; margin-bottom: 3rem; }
.sec-head .idx { font-family: var(--mono); font-size: 12px; color: var(--accent); }
.sec-head h2 { font-family: var(--mono); font-size: 12px; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); }
.sec-head .rule { flex: 1; height: 1px; background: var(--line); }

.about-lead { font-family: var(--serif); font-size: clamp(22px, 3.4vw, 30px); line-height: 1.6; font-weight: 400; margin-bottom: 2rem; max-width: 24ch; }
.about-lead .accent { color: var(--accent); font-style: italic; }
.about-body { font-size: 15px; color: var(--muted); max-width: 52ch; font-weight: 300; }
.title-block { display: flex; flex-wrap: wrap; gap: 1px; margin-top: 2.5rem; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--line); }
.title-item { flex: 1; min-width: 200px; background: var(--surface); backdrop-filter: blur(12px); padding: 1rem 1.25rem; display: flex; flex-direction: column; gap: 3px; }
.title-item .ti-role { font-family: var(--serif); font-size: 15px; color: var(--ink); }
.title-item .ti-pos { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: 0.04em; }
.stack-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 2.5rem; }
.chip { font-family: var(--mono); font-size: 11px; color: var(--muted); border: 1px solid var(--line-hi); padding: 5px 12px; border-radius: 100px; transition: all 0.25s ease; }
.chip:hover { color: var(--accent); border-color: var(--accent-dim); background: var(--accent-dim); }

/* timeline (Background) */
.timeline { display: flex; flex-direction: column; }
.tl-item { display: flex; gap: 2rem; padding: 1.5rem 0; border-bottom: 1px solid var(--line); position: relative; }
.tl-item:last-child { border-bottom: none; }
.tl-year { font-family: var(--mono); font-size: 13px; color: var(--accent); min-width: 72px; padding-top: 3px; letter-spacing: 0.02em; }
.tl-body { flex: 1; }
.tl-title { font-family: var(--serif); font-size: 19px; font-weight: 500; margin-bottom: 0.4rem; }
.tl-desc { font-size: 14px; color: var(--muted); line-height: 1.8; font-weight: 300; max-width: 56ch; }

/* tech stack grid */
.stack-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 14px; overflow: hidden; }
.stack-cat { background: var(--surface); backdrop-filter: blur(12px); padding: 1.4rem 1.6rem; }
.sc-label { font-family: var(--mono); font-size: 11px; color: var(--accent); letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 0.9rem; }
.sc-chips { display: flex; flex-wrap: wrap; gap: 7px; }

/* hobbies */
.hobby-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.hobby-card { border: 1px solid var(--line); border-radius: 16px; overflow: hidden; background: var(--surface); backdrop-filter: blur(12px); box-shadow: var(--card-shadow); transition: transform 0.4s cubic-bezier(0.2,0.7,0.2,1), box-shadow 0.4s ease, border-color 0.4s ease; }
.hobby-card:hover { transform: translateY(-4px); box-shadow: var(--card-shadow-hi); border-color: var(--line-hi); }
.hobby-ph { height: 170px; position: relative; display: flex; align-items: center; justify-content: center; background: linear-gradient(160deg, var(--surface-hi), var(--surface)); border-bottom: 1px solid var(--line); }
.hobby-ph::before { content: ""; position: absolute; inset: 14px; border: 1px dashed var(--line-hi); border-radius: 8px; }
.ph-mark { font-family: var(--mono); font-size: 10px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--faint); }
.hobby-cap { padding: 1rem 1.25rem; display: flex; flex-direction: column; gap: 3px; }
.hobby-name { font-family: var(--mono); font-size: 12px; color: var(--accent); letter-spacing: 0.06em; }
.hobby-note { font-size: 13px; color: var(--muted); font-weight: 300; }

.work-grid { display: flex; flex-direction: column; gap: 1.25rem; }
.work-card { position: relative; display: block; text-decoration: none; color: inherit; background: var(--surface); backdrop-filter: blur(12px); border: 1px solid var(--line); border-radius: 16px; padding: 2rem 2.25rem; overflow: hidden; box-shadow: var(--card-shadow); transition: transform 0.4s cubic-bezier(0.2,0.7,0.2,1), border-color 0.4s ease, background 0.4s ease, box-shadow 0.4s ease; }
.work-card::before { content: ""; position: absolute; inset: 0; border-radius: 16px; background: radial-gradient(500px 200px at var(--mx,50%) var(--my,0%), var(--glow), transparent 70%); opacity: 0; transition: opacity 0.4s ease; pointer-events: none; }
.work-card:hover { transform: translateY(-4px); border-color: var(--line-hi); background: var(--surface-hi); box-shadow: var(--card-shadow-hi); }
.work-card:hover::before { opacity: 1; }
.work-card:hover .wc-arrow { color: var(--accent); transform: translate(4px,-4px); }
.work-top { display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 1rem; }
.wc-num { font-family: var(--mono); font-size: 12px; color: var(--faint); }
.wc-arrow { font-family: var(--mono); font-size: 18px; color: var(--muted); transition: all 0.35s ease; }
.wc-badge { font-family: var(--mono); font-size: 10px; letter-spacing: 0.06em; color: var(--accent); border: 1px solid var(--accent-dim); background: var(--accent-dim); padding: 3px 9px; border-radius: 100px; }
.wc-meta { display: inline-flex; align-items: center; gap: 12px; }
.work-card.is-private { cursor: default; }
.work-card.is-private:hover { transform: translateY(-4px); }
.wc-title { font-family: var(--serif); font-size: 26px; font-weight: 500; margin-bottom: 0.6rem; letter-spacing: 0.005em; }
.wc-desc { font-size: 14px; color: var(--muted); line-height: 1.8; font-weight: 300; max-width: 60ch; }
.wc-tags { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 1.5rem; }
.wc-tag { font-family: var(--mono); font-size: 10.5px; color: var(--faint); letter-spacing: 0.03em; padding: 3px 9px; border: 1px solid var(--line); border-radius: 6px; }

.contact-wrap { display: flex; flex-direction: column; gap: 2.5rem; }
.contact-cta { font-family: var(--serif); font-size: clamp(26px, 5vw, 44px); font-weight: 400; line-height: 1.3; }
.contact-cta a { color: var(--accent); text-decoration: none; border-bottom: 1px solid var(--accent-dim); transition: border-color 0.3s ease; }
.contact-cta a:hover { border-color: var(--accent); }
.contact-links { display: flex; flex-wrap: wrap; gap: 1.75rem; }
.contact-links a { font-family: var(--mono); font-size: 13px; color: var(--muted); text-decoration: none; display: inline-flex; align-items: center; gap: 7px; transition: color 0.25s ease; }
.contact-links a:hover { color: var(--accent); }
.contact-links a .ar { font-size: 11px; }

footer { padding: 3rem 0 4rem; border-top: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; font-family: var(--mono); font-size: 11px; color: var(--faint); letter-spacing: 0.03em; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.9s cubic-bezier(0.2,0.7,0.2,1), transform 0.9s cubic-bezier(0.2,0.7,0.2,1); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .dot { animation: none; } .bg-aura { animation: none; }
  html { scroll-behavior: auto; }
}
@media (max-width: 620px) {
  .wrap { padding: 0 1.5rem; }
  nav { padding: 1.25rem 1.5rem; }
  .hero { padding: 6rem 0 3.5rem; }
  section { padding: 3.5rem 0; }
  .work-card { padding: 1.75rem 1.5rem; }
  footer { flex-direction: column; gap: 1rem; align-items: flex-start; }
  .nav-meta { display: none; }
  .stack-grid { grid-template-columns: 1fr; }
  .hobby-grid { grid-template-columns: 1fr; }
  .tl-item { gap: 1rem; }
  .tl-year { min-width: 60px; }
}