@media (max-width: 900px) {
  .timeline-single-line { white-space: normal; }
  .landing-content h1 { font-size: clamp(3.4rem, 9vw, 5.2rem); }
  .qa-test-section, .qa-test-section.workflow-open { height: auto; min-height: calc(100svh - 66px); overflow: visible; }
  .qa-test-wrap, .qa-test-section.workflow-open .qa-test-wrap { height: auto; }
  .qa-section-heading { grid-template-columns: 1fr; gap: 12px; }
  .comparison-workspace { padding: 12px; }
  .challenge { grid-template-columns: 1fr; }
  .chatbot-app { min-height: 390px; }
  .philosophy-wrap { grid-template-columns: 1fr; }
  .collaboration-visual { width: min(100%, 570px); margin: 0 auto; }
}

@media (max-width: 720px) {
  .wrap { width: min(100% - 32px, 560px); }
  .landing-content { padding-block: 28px; }
  .landing-content::before { display: none; }
  .landing-index { margin-top: 22px; }
  .landing-content h1 { font-size: clamp(2.65rem, 13.8vw, 4.25rem); }
  .intro-copy { margin-top: 16px; font-size: .88rem; line-height: 1.62; }
  .path-selector { grid-template-columns: 1fr; gap: 10px; margin-top: 24px; }
  .path-card { min-height: 104px; grid-template-columns: 28px 1fr 34px; padding: 15px; }
  .path-arrow { width: 34px; height: 34px; }
  .landing-footnote { margin-top: 13px; }

  .site-header-inner { width: min(100% - 32px, 1120px); min-height: 58px; gap: 14px; }
  .site-header-brand { font-size: .7rem; }
  .site-header-actions { gap: 8px; }
  .site-home { width: 32px; height: 32px; flex-basis: 32px; }
  .journey-portfolio { min-height: 32px; padding: 0 9px; font-size: .65rem; }
  .qa-test-section, .qa-test-section.workflow-open { height: auto; min-height: calc(100svh - 58px); padding: 26px 0 46px; overflow: visible; scroll-margin-top: 58px; }
  .qa-test-wrap, .qa-test-section.workflow-open .qa-test-wrap { height: auto; }
  .qa-section-heading { margin-bottom: 22px; }
  .qa-section-heading h2 { font-size: clamp(2rem, 10vw, 2.8rem); }
  .qa-heading-aside { align-items: flex-start; flex-direction: column; gap: 10px; }
  .qa-heading-aside > p { font-size: .82rem; }
  .comparison-workspace { padding: 10px; border-radius: 17px; }
  .challenge { gap: 14px; }
  .spec-card { padding: 15px; }
  .challenge-guide h3 { font-size: 1.25rem; }
  .spec-meta div { padding-inline: 6px; }
  .spec-meta dt { font-size: .5rem; }
  .spec-meta dd { font-size: .58rem; }
  .design-annotations { grid-template-columns: 1fr; }
  .blueprint-canvas { padding: 10px; }
  .citation-component { grid-template-columns: 28px 1fr auto; }
  .ac-row { grid-template-columns: 38px .9fr 1fr; }
  .chatbot-app { min-height: 330px; }
  .chat-window { min-height: 110px; }
  .chat-message { font-size: .68rem; }
  .defect-workflow.show { margin-top: 25px; }
  .workflow-rail { gap: 5px; }
  .workflow-step { gap: 4px; font-size: .58rem; }
  .workflow-step i { width: 20px; height: 20px; }
  .defect-card { padding: 17px; }
  .defect-card-head h3 { font-size: 1rem; }
  .defect-fields { grid-template-columns: 1fr; }
  .defect-action { align-items: stretch; flex-direction: column; gap: 13px; }
  .defect-action button { width: 100%; }
  .scroll-story { max-width: 100%; font-size: .7rem; }

  .qa-philosophy { padding: 46px 0 54px; scroll-margin-top: 58px; }
  .philosophy-wrap { gap: 48px; }
  .philosophy-copy h2 { font-size: clamp(2.1rem, 10vw, 3rem); }
  .philosophy-copy > p, .philosophy-copy blockquote { font-size: .9rem; }
  .philosophy-copy blockquote { padding: 15px 40px 15px 16px; }
  .collaboration-visual { min-height: 420px; }
  .qa-philosophy.is-visible .collaboration-visual { transform: none; }
  .ring-one { width: min(220px, 62%); height: auto; aspect-ratio: 1; }
  .ring-two { width: min(350px, 94%); height: auto; aspect-ratio: 1; }
  .qa-core { width: 132px; height: 132px; }
  .qa-core strong { font-size: 2.1rem; }
  .collaborator { min-width: 106px; padding: 10px 11px; }
  .collaborator small { font-size: .66rem; }
  .collaborator::after { width: 50px; }
  .plan { left: 0; }
  .design { right: 0; }
  .develop { right: 0; }
  .engineer { left: 0; }
  .quality-lifecycle { padding: 17px; overflow-x: auto; }
  .quality-lifecycle ol { min-width: 620px; }
  .qa-throughline { min-width: 620px; }
  .lifecycle-head { align-items: flex-start; flex-direction: column; gap: 4px; }
  .philosophy-ending { align-items: stretch; flex-direction: column; gap: 16px; }
  .philosophy-ending a { width: 100%; }

  /* Portfolio */
  .section { padding: 75px 0; }
  .nav-toggle { display: inline-flex; margin-left: 0; }
  .nav-links { position: absolute; top: calc(100% + 8px); left: 16px; right: 16px; display: grid; gap: 2px; padding: 8px; border: 1px solid var(--line); border-radius: 13px; background: rgba(255,255,255,.98); box-shadow: var(--shadow); opacity: 0; visibility: hidden; transform: translateY(-8px); transition: opacity .2s ease, transform .2s ease, visibility .2s; }
  .nav-links.open { opacity: 1; visibility: visible; transform: none; }
  .nav .nav-links a { display: block; padding: 10px 12px; border-radius: 8px; font-size: .78rem; }
  .nav .nav-links a::after { display: none; }
  .nav .nav-links a:hover, .nav .nav-links a[aria-current="page"] { background: #eef3ff; }
  .hero-grid, .timeline-item, .project-card { grid-template-columns: 1fr; }
  .portfolio-hero { min-height: calc(100svh - 58px); padding: 44px 0 54px; }
  .portfolio-hero h2 { font-size: clamp(2.5rem, 12vw, 3.7rem); }
  .hero-stat { padding: 12px; }
  .hero-stat strong { font-size: 1.08rem; }
  .competency-grid, .ai-grid, .process-grid, .skills-grid { grid-template-columns: 1fr; }
  .project-card { padding: 22px; }
  .project-summary > div { grid-template-columns: 76px 1fr; gap: 10px; }
  .section-heading { margin-bottom: 32px; padding-bottom: 21px; }
  .section-heading h2 { max-width: none; margin: 11px 0 13px; }
}

@media (max-width: 430px) {
  .eyebrow { font-size: .6rem; }
  .landing-index { display: none; }
  .landing-content h1 { margin-top: 20px; }
  .path-copy > span { font-size: .72rem; }
  .brand span { display: none; }
  .spec-flow { overflow-x: auto; }
  .workflow-step { font-size: 0; }
  .workflow-step i { font-size: .58rem; }
  .collaboration-visual { min-height: 400px; transform-origin: center; }
  .qa-philosophy.is-visible .collaboration-visual { transform: none; }
  .ring-two { width: min(320px, 100%); height: auto; aspect-ratio: 1; }
}

@media (max-height: 720px) and (min-width: 721px) {
  .landing-content { padding-block: 26px; }
  .landing-index { margin-top: 18px; }
  .landing-content h1 { font-size: clamp(3rem, 8.2vh, 4.6rem); }
  .intro-copy { margin-top: 13px; }
  .path-selector { margin-top: 20px; }
  .path-card { min-height: 108px; padding-block: 16px; }
  .landing-footnote { margin-top: 11px; }
}

@media (max-width: 720px) and (max-height: 650px) {
  .landing-content { padding-block: 18px; }
  .eyebrow, .landing-footnote { display: none; }
  .landing-content h1 { margin-top: 0; font-size: clamp(2.3rem, 11.5vw, 3.15rem); }
  .intro-copy { margin-top: 10px; font-size: .78rem; line-height: 1.45; }
  .path-selector { gap: 7px; margin-top: 15px; }
  .path-card { min-height: 84px; padding: 10px 13px; }
  .path-copy strong { margin: 3px 0; font-size: 1rem; }
  .path-copy > span { font-size: .66rem; }
}