/* ============================================================
   Design Tokens
   ============================================================ */
:root {
  --bg:          #FFFFFF;
  --bg-gray:     #F7F6F4;
  --bg-dark:     #1A1A1A;
  --text-1:      #1A1A1A;
  --text-2:      #666666;
  --text-3:      #999999;
  --border:      #E8E6E2;
  --font:        -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans',
                 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', sans-serif;
  --nav-h:       64px;
  --ease:        0.3s ease;
  --radius-s:    4px;
  --radius-m:    8px;
  --radius-l:    16px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-1);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img, svg { display: block; max-width: 100%; }
a        { color: inherit; text-decoration: none; }
button   { cursor: pointer; border: none; background: none; font-family: inherit; }
ul       { list-style: none; }

/* ============================================================
   Typography helpers
   ============================================================ */
h1, h2, h3 { line-height: 1.25; letter-spacing: -0.02em; }

/* ============================================================
   Layout
   ============================================================ */
.container {
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section        { padding: 5rem 0; }
.section--gray  { background: var(--bg-gray); }
.section--dark  { background: var(--bg-dark); }

.section__header { margin-bottom: 3.5rem; text-align: center; }

.section__label {
  display: block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 0.5rem;
}
.section__label--light { color: #555; }

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 300;
  letter-spacing: -0.03em;
}
.section__title--light { color: #FFFFFF; }

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 52px;
  padding: 0 2rem;
  border-radius: var(--radius-s);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  transition: opacity var(--ease);
  min-width: 160px;
}

.btn--primary {
  background: var(--bg-dark);
  color: #FFF;
}
.btn--primary:active { opacity: 0.7; }

@media (hover: hover) {
  .btn--primary:hover { opacity: 0.78; }
}

.btn--submit {
  width: 100%;
  background: #FFF;
  color: var(--bg-dark);
  font-size: 0.9375rem;
  height: 56px;
  border-radius: var(--radius-s);
}
.btn--submit:active { opacity: 0.8; }
@media (hover: hover) {
  .btn--submit:hover { opacity: 0.85; }
}

/* ============================================================
   Navigation
   ============================================================ */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--nav-h);
  z-index: 200;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--ease);
}
.nav.scrolled { border-bottom-color: var(--border); }

.nav__inner {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.nav__menu { display: none; gap: 2.5rem; }

.nav__link {
  font-size: 0.8125rem;
  color: var(--text-2);
  letter-spacing: 0.06em;
  position: relative;
  transition: color var(--ease);
}
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0; right: 0;
  height: 1px;
  background: var(--text-1);
  transform: scaleX(0);
  transition: transform var(--ease);
}
.nav__link:hover { color: var(--text-1); }
.nav__link:hover::after { transform: scaleX(1); }

/* Hamburger */
.nav__hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  -webkit-tap-highlight-color: transparent;
}
.nav__hamburger span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--text-1);
  transition: transform var(--ease), opacity var(--ease);
  transform-origin: center;
}
.nav__hamburger.active span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.nav__hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.nav__hamburger.active span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* ============================================================
   Mobile Menu
   ============================================================ */
.mobile-menu {
  position: fixed;
  inset: var(--nav-h) 0 0 0;
  background: var(--bg);
  z-index: 199;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2.75rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity 0.28s ease, transform 0.28s ease;
}
.mobile-menu.open {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.mobile-menu__link {
  font-size: 2rem;
  font-weight: 300;
  letter-spacing: 0.12em;
  -webkit-tap-highlight-color: transparent;
  transition: opacity var(--ease);
}
.mobile-menu__link:active { opacity: 0.4; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  min-height: 100svh;
  min-height: 100vh;
  padding-top: var(--nav-h);
  display: flex;
  align-items: center;
  padding-bottom: 3rem;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  align-items: center;
  padding-top: 3rem;
}

.hero__label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 1.25rem;
}

.hero__title {
  font-size: clamp(2.25rem, 9vw, 4.75rem);
  font-weight: 300;
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
}

.hero__desc {
  font-size: 1rem;
  color: var(--text-2);
  line-height: 1.85;
  max-width: 440px;
  margin-bottom: 2.5rem;
}

.hero__visual { display: none; }

.hero__svg { width: 100%; }

/* ============================================================
   Works Grid
   ============================================================ */
.works__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.75rem;
}

/* ============================================================
   Work Card
   ============================================================ */
.work-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-l);
  overflow: hidden;
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.55s ease, transform 0.55s ease, border-color var(--ease);
  -webkit-tap-highlight-color: transparent;
}
.work-card.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (hover: hover) {
  .work-card:hover {
    border-color: #C4C0BA;
    transform: translateY(-5px);
  }
}

.work-card__image {
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: #F8F7F5;
  line-height: 0;
}
.work-card__image svg {
  width: 100%;
  height: 100%;
  transition: transform 0.45s ease;
}
@media (hover: hover) {
  .work-card:hover .work-card__image svg { transform: scale(1.025); }
}

.work-card__body { padding: 1.375rem 1.5rem 1.5rem; }

.work-card__tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 0.5rem;
}

.work-card__title {
  font-size: 1.0625rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  margin-bottom: 0.5rem;
  color: var(--text-1);
  line-height: 1.4;
}

.work-card__desc {
  font-size: 0.875rem;
  color: var(--text-2);
  line-height: 1.75;
  margin-bottom: 1rem;
}

.work-card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.work-card__metric {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  background: var(--bg-gray);
  border-radius: 100px;
  font-size: 0.75rem;
  color: var(--text-2);
  letter-spacing: 0.02em;
}

/* ============================================================
   About
   ============================================================ */
.about {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3.5rem;
  align-items: center;
}

.about__visual { display: none; }

.about__svg {
  width: 100%;
  max-width: 340px;
  margin: 0 auto;
}

.about__profile { margin-bottom: 2rem; }

.about__name {
  font-size: clamp(1.5rem, 4vw, 1.875rem);
  font-weight: 300;
  letter-spacing: -0.02em;
  margin-bottom: 1.125rem;
  display: flex;
  align-items: baseline;
  gap: 0.875rem;
  flex-wrap: wrap;
}

.about__name-en {
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--text-3);
  letter-spacing: 0.06em;
}

.about__bio {
  font-size: 0.9375rem;
  color: var(--text-2);
  line-height: 1.9;
  margin-bottom: 0.875rem;
}

.about__facts {
  display: flex;
  gap: 2.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
}

.about__fact {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.about__fact-num {
  font-size: 2.25rem;
  font-weight: 300;
  letter-spacing: -0.04em;
  line-height: 1;
}

.about__fact-unit { font-size: 1.125rem; font-weight: 300; }

.about__fact-label {
  font-size: 0.75rem;
  color: var(--text-3);
  letter-spacing: 0.04em;
  margin-top: 0.125rem;
}

/* ============================================================
   Skills
   ============================================================ */
.skills__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.skill-group__title {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--text-3);
  margin-bottom: 1.375rem;
  padding-bottom: 0.875rem;
  border-bottom: 1px solid var(--border);
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 1.125rem;
}

.skill-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.skill-item__name {
  font-size: 0.875rem;
  color: var(--text-1);
}

.skill-item__bar {
  height: 2px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.skill-item__fill {
  height: 100%;
  background: var(--text-1);
  border-radius: 2px;
  width: 0;
  transition: width 1.1s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Tool badges */
.tools {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tool-badge {
  display: inline-block;
  padding: 0.375rem 0.875rem;
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.8125rem;
  color: var(--text-2);
  letter-spacing: 0.02em;
  background: var(--bg);
}

/* ============================================================
   Contact
   ============================================================ */
.contact {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3.5rem;
}

.contact__content .section__title { margin-bottom: 0; }

.contact__desc {
  font-size: 0.9375rem;
  color: #888;
  line-height: 1.85;
  margin-top: 0.75rem;
  margin-bottom: 1.75rem;
}

.contact__info {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.contact__info-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: #777;
}

/* Form */
.contact__form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-label {
  font-size: 0.8rem;
  color: #666;
  letter-spacing: 0.03em;
}

.form-input {
  width: 100%;
  height: 52px;
  padding: 0 1rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid #2E2E2E;
  border-radius: var(--radius-s);
  color: #FFFFFF;
  font-family: var(--font);
  font-size: 0.9375rem;
  outline: none;
  transition: border-color var(--ease), background var(--ease);
  -webkit-appearance: none;
  appearance: none;
}
.form-input::placeholder { color: #4A4A4A; }
.form-input:focus {
  border-color: #555;
  background: rgba(255, 255, 255, 0.07);
}

.form-select {
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'%3E%3Cpath d='M4 6L8 10L12 6' stroke='%23666' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}
.form-select option { background: #1A1A1A; }

.form-textarea {
  height: auto;
  min-height: 136px;
  padding: 0.875rem 1rem;
  resize: vertical;
  line-height: 1.75;
}

.form-note {
  font-size: 0.75rem;
  color: #3A3A3A;
  text-align: center;
  margin-top: -0.375rem;
}

/* Form success state */
.form-success {
  text-align: center;
  padding: 3.5rem 1.5rem;
  opacity: 0;
  transition: opacity 0.4s ease;
}
.form-success.visible { opacity: 1; }

.form-success__icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 1.25rem;
  border: 1.5px solid #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.form-success__title {
  font-size: 1.25rem;
  font-weight: 400;
  color: #FFFFFF;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.form-success__desc {
  font-size: 0.875rem;
  color: #666;
  line-height: 1.8;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  background: var(--bg-dark);
  border-top: 1px solid #262626;
  padding: 2.5rem 0;
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  text-align: center;
}

.footer__logo {
  font-size: 1rem;
  font-weight: 600;
  color: #FFFFFF;
  letter-spacing: 0.08em;
}

.footer__nav {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.footer__nav a {
  font-size: 0.8125rem;
  color: #555;
  letter-spacing: 0.05em;
  transition: color var(--ease);
}
.footer__nav a:hover { color: #FFFFFF; }

.footer__copy {
  font-size: 0.75rem;
  color: #3A3A3A;
}

/* ============================================================
   Reveal animation
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   Responsive — Tablet ≥ 640px
   ============================================================ */
@media (min-width: 640px) {
  .container { padding: 0 2rem; }

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

  .hero__inner {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    padding-top: 2rem;
  }
  .hero__visual {
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .hero__title { font-size: clamp(2rem, 5.5vw, 4.5rem); }
}

/* ============================================================
   Responsive — Desktop ≥ 1024px
   ============================================================ */
@media (min-width: 1024px) {
  .nav__menu    { display: flex; }
  .nav__hamburger { display: none; }

  .section { padding: 6.5rem 0; }

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

  .about {
    grid-template-columns: 5fr 7fr;
    gap: 5rem;
  }
  .about__visual { display: block; }

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

  .contact {
    grid-template-columns: 5fr 7fr;
    gap: 5rem;
    align-items: start;
  }
  .contact__content { padding-top: 1rem; }
}

/* ============================================================
   Responsive — Large Desktop ≥ 1280px
   ============================================================ */
@media (min-width: 1280px) {
  .hero__inner {
    grid-template-columns: 1fr 1fr;
    gap: 6rem;
  }
}

/* ============================================================
   Accessibility
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .work-card, .reveal { opacity: 1; transform: none; }
}