:root {
  color-scheme: light;
  /* README 디자인 시스템 / indexstyle.css. Text accents use readable shades. */
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --ink: #333333;
  --muted: #666666;
  --paper: #f8f9fa;
  --line: #d1d5db;
  --accent: #1d4ed8;
  --accent-hover: #1e40af;
  --surface: #ffffff;
  --tint: #f3f4f6;
  --accent-soft: #eff6ff;
  --soft-line: #bfdbfe;
  --hero-bg: var(--paper);
  --hero-glow: #dbeafe;
  --card-shadow: #17255416;
  --control-bg: #2563eb;
  --control-ink: #ffffff;
  --header-height: 76px;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --primary-color: #dc2626;
  --primary-hover: #b91c1c;
  --ink: #ffffff;
  --muted: #cccccc;
  --paper: #0a0a0a;
  --line: #333333;
  --accent: #fca5a5;
  --accent-hover: #fecaca;
  --surface: #171717;
  --tint: #141414;
  --accent-soft: #251414;
  --soft-line: #542020;
  --hero-bg: var(--paper);
  --hero-glow: #2e1111;
  --card-shadow: #0005;
  --control-bg: #dc2626;
  --control-ink: #ffffff;
}
* { box-sizing: border-box; }
html { scroll-padding-top: 146px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: "Pretendard", "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", system-ui, sans-serif; font-size: 16px; line-height: 1.8; word-break: keep-all; overflow-wrap: anywhere; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
img { display: block; max-width: 100%; height: auto; }
figure, p, h1, h2, h3, dl, dd { margin: 0; }
h1, h2, h3 { line-height: 1.25; letter-spacing: -.045em; }
em { font-style: normal; }
button[hidden] { display: none; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; }
.wrap { width: min(1240px, calc(100% - 80px)); margin-inline: auto; }
.skip-link { position: fixed; top: 10px; left: 12px; z-index: 100; padding: 10px 18px; background: var(--control-bg); color: var(--control-ink); transform: translateY(-200%); }
.skip-link:focus { transform: none; }
.identity-header { position: sticky; top: 0; z-index: 30; background: var(--paper); color: var(--ink); border-bottom: 1px solid var(--line); }
.header-inner { min-height: var(--header-height); display: flex; align-items: center; gap: 36px; }
.brand { display: inline-flex; align-items: center; gap: 9px; font-family: Arial, sans-serif; font-size: 25px; font-weight: 800; letter-spacing: -1.1px; line-height: 1; white-space: nowrap; }
.brand-dot { width: 6px; height: 6px; background: var(--primary-color); border-radius: 50%; align-self: flex-end; }
.header-links { display: flex; align-items: center; gap: 24px; margin-left: auto; font-size: 14px; color: var(--muted); }
.header-links a { padding-block: 12px; }
.header-links a:hover { color: var(--accent); }
.header-actions { display: flex; align-items: center; gap: 12px; }
.theme-toggle { display: inline-flex; align-items: center; justify-content: center; width: 44px; height: 44px; flex-shrink: 0; padding: 0; border: 1px solid var(--line); border-radius: 6px; background: var(--surface); color: var(--ink); }
.theme-toggle:hover { border-color: var(--accent); }
.theme-sun { display: none; }
[data-theme="dark"] .theme-moon { display: none; }
[data-theme="dark"] .theme-sun { display: initial; }
.button { min-height: 50px; display: inline-flex; align-items: center; justify-content: center; gap: 26px; padding: 13px 22px; border: 1px solid transparent; border-radius: 5px; font-size: 15px; font-weight: 800; line-height: 1.5; text-align: center; }
.button span { font-size: 21px; line-height: 1; }
.button-primary { background: var(--control-bg); color: var(--control-ink); }
.button-primary:hover { background: var(--primary-hover); }
.header-cta { min-height: 42px; padding: 10px 16px; font-size: 13px; gap: 15px; white-space: nowrap; }
.button-dark { color: var(--control-ink); background: var(--control-bg); }
.button-dark:hover { filter: brightness(1.12); }
.button-outline { border-color: var(--muted); color: var(--ink); }
.button-outline:hover { border-color: var(--accent); }
.hero { color: var(--ink); background: radial-gradient(ellipse at 90% 45%, var(--hero-glow) 0, transparent 52%), var(--hero-bg); }
.hero-grid { display: grid; grid-template-columns: 1fr 1.06fr; gap: 45px; padding-block: 68px 48px; align-items: center; }
.eyebrow { color: var(--muted); font-size: 13px; font-weight: 700; letter-spacing: .035em; }
.live-dot { display: inline-block; width: 7px; height: 7px; margin-right: 8px; border-radius: 50%; background: var(--accent); }
.hero h1 { margin-top: 23px; font-size: clamp(45px, 4.5vw, 67px); font-weight: 900; line-height: 1.14; letter-spacing: -.065em; }
.hero h1 em, .final-cta em { color: var(--accent); }
.hero-promise { margin-top: 24px; color: var(--ink); font-size: 20px; font-weight: 700; line-height: 1.65; }
.hero-description { margin-top: 13px; font-size: 15px; color: var(--muted); line-height: 1.9; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 20px; margin-top: 25px; }
.text-link { display: inline-flex; gap: 20px; align-items: center; padding-block: 10px; font-size: 15px; font-weight: 800; color: var(--accent); text-decoration: underline; text-underline-offset: 6px; text-decoration-thickness: 1px; }
.text-link span { text-decoration: none; }
.text-link:hover { color: var(--accent-hover); }
.text-link.light { color: var(--accent); font-size: 13px; }
.hero-visual { min-width: 0; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--surface); box-shadow: 0 30px 80px var(--card-shadow); }
.visual-topline { display: flex; justify-content: space-between; gap: 12px; padding: 16px 20px; color: var(--muted); font-size: 12px; border-bottom: 1px solid var(--line); }
.hero-visual img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.hero-workflow { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 9px; padding: 20px 20px 8px; color: var(--ink); font-size: 12px; }
.hero-workflow b { margin-right: 5px; color: var(--accent); font-family: Arial, sans-serif; }
.hero-workflow > span:nth-child(even) { color: var(--muted); }
.visual-caption { padding: 0 20px 18px; color: var(--muted); font-size: 11px; }
.hero-bottom { display: grid; grid-template-columns: 1fr 1.5fr; gap: 36px; padding-block: 28px 35px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; }
.hero-bottom strong { color: var(--ink); font-weight: 700; }
.hero-bottom > p:first-child { font-size: 16px; line-height: 1.7; }
.section-intro { max-width: 810px; }
.kicker { color: var(--accent); font-size: 13px; font-weight: 800; letter-spacing: .015em; }
.section-intro h2 { margin-top: 14px; font-size: clamp(29px, 3.1vw, 42px); }
.section-intro > p:last-child { max-width: 710px; margin-top: 19px; color: var(--muted); line-height: 1.9; }
.why-section { padding-block: 70px 54px; }
.question-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 34px; margin-top: 36px; }
.question-grid article { border-top: 2px solid var(--soft-line); padding-top: 18px; }
.question-number { color: var(--accent); font: 13px/1 Arial, sans-serif; }
.question-grid h3 { margin-top: 11px; font-size: 20px; }
.question-grid p { margin-top: 13px; font-size: 15px; color: var(--muted); }
.manifesto { display: flex; align-items: center; gap: 22px; padding: 22px 26px; margin-top: 30px; background: var(--accent-soft); border-left: 3px solid var(--accent); font-size: 14px; color: var(--muted); }
.manifesto > span { font-size: 32px; color: var(--accent); }
.manifesto strong { display: inline-block; margin-bottom: 4px; font-size: 16px; color: var(--ink); }
.mobile-break { display: none; }
.chapter-nav { position: sticky; top: var(--header-height); z-index: 20; color: var(--ink); background: var(--surface); border-block: 1px solid var(--line); }
.chapter-links { display: flex; justify-content: space-between; gap: 20px; }
.chapter-links a { display: flex; align-items: center; gap: 14px; padding: 16px 6px 13px; white-space: nowrap; font-size: 14px; border-bottom: 3px solid transparent; }
.chapter-links span { color: var(--muted); font: 12px Arial, sans-serif; }
.chapter-links a:hover, .chapter-links a[aria-current="location"] { color: var(--accent); border-bottom-color: var(--accent); }
.chapter { padding-block: 65px; scroll-margin-top: 8px; }
.chapter + .chapter:not(.chapter-tinted) { border-top: 1px solid var(--line); }
.chapter-tinted { background: var(--tint); }
.chapter-heading { margin-bottom: 30px; }
.chapter-heading .kicker { display: flex; gap: 13px; align-items: center; }
.kicker > span { color: var(--accent); background: var(--accent-soft); border: 1px solid var(--soft-line); padding: 2px 8px; font-family: Arial, sans-serif; font-size: 11px; }
.chapter-heading h2 { margin-top: 13px; font-size: clamp(29px, 3vw, 40px); }
.chapter-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: start; }
.chapter-copy { min-width: 0; }
.chapter-copy > p { color: var(--muted); font-size: 15px; line-height: 1.95; }
.chapter-copy > .chapter-lead { color: var(--ink); font-size: 18px; font-weight: 700; line-height: 1.75; margin-bottom: 13px; }
.benefit-list { margin-block: 21px 12px; }
.benefit-list > div { padding-block: 15px; border-top: 1px solid var(--line); }
.benefit-list dt { font-size: 16px; font-weight: 800; line-height: 1.6; }
.benefit-list dt::before { content: "↗"; display: inline-block; margin-right: 9px; color: var(--accent); }
.benefit-list dd { margin-top: 5px; color: var(--muted); font-size: 14px; line-height: 1.9; }
.chapter-copy > .inline-note { padding: 12px 15px; margin-bottom: 11px; border-left: 2px solid var(--soft-line); font-size: 12px; color: var(--muted); background: var(--accent-soft); }
.chapter-figure { min-width: 0; border-radius: 8px; overflow: hidden; background: var(--surface); color: var(--ink); border: 1px solid var(--line); }
.chapter-figure img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.chapter-figure figcaption { padding: 14px 21px; color: var(--muted); font-size: 12px; line-height: 1.8; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.chapter-figure figcaption span { display: block; color: var(--ink); font-size: 11px; }
.takeaway { padding: 22px 25px 25px; background: var(--accent-soft); }
.takeaway > span { display: block; color: var(--muted); font-size: 12px; margin-bottom: 9px; }
.takeaway strong { display: block; color: var(--accent); font-size: 24px; line-height: 1.45; letter-spacing: -.04em; }
.chapter-reverse .chapter-figure { order: -1; }
.prompt-box { display: grid; grid-template-columns: .9fr 1.1fr; gap: 40px; padding: 28px; margin-top: 35px; background: var(--accent-soft); border: 1px solid var(--soft-line); border-radius: 8px; }
.prompt-box h3 { margin-top: 10px; font-size: 21px; }
.prompt-box p { font-size: 13px; color: var(--muted); margin-top: 12px; }
.prompt-content { min-width: 0; }
.prompt-content pre { white-space: pre-wrap; overflow-wrap: anywhere; margin: 0; font: 14px/1.9 "Malgun Gothic", sans-serif; color: var(--ink); }
.prompt-controls { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-top: 15px; }
.prompt-controls .button { min-height: 42px; font-size: 13px; padding: 9px 15px; }
.prompt-controls #copy-status { margin: 0; }
.start-section { display: grid; grid-template-columns: 1fr 1fr; gap: 68px; padding-block: 70px; }
.start-section .section-intro h2 { font-size: 34px; }
.start-steps { list-style: none; margin: 0; padding: 0; }
.start-steps li { display: flex; gap: 18px; padding-block: 20px; border-top: 1px solid var(--line); }
.start-steps li > span { color: var(--accent); font: 14px Arial, sans-serif; padding-top: 5px; }
.start-steps h3 { font-size: 18px; }
.start-steps p { color: var(--muted); font-size: 14px; margin-top: 9px; }
.faq-section { border-top: 1px solid var(--line); display: grid; grid-template-columns: .7fr 1.3fr; gap: 65px; padding-block: 55px 65px; }
.faq-section h2 { font-size: 33px; margin-block: 13px 15px; }
.faq-list { min-width: 0; }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; padding: 18px 27px 18px 0; font-size: 16px; font-weight: 700; position: relative; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 3px; top: 15px; font: 24px Arial, sans-serif; font-weight: 400; color: var(--accent); }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { padding: 0 23px 20px 0; color: var(--muted); font-size: 14px; line-height: 1.9; }
.faq-list a { text-decoration: underline; text-underline-offset: 3px; color: var(--accent); }
.final-cta { padding-block: 63px; background: radial-gradient(ellipse at 85% 20%, var(--hero-glow), transparent 55%), var(--hero-bg); border-block: 1px solid var(--line); color: var(--ink); text-align: center; }
.final-cta h2 { margin-top: 20px; font-size: clamp(30px, 3.7vw, 48px); }
.final-cta .wrap > p:not(.eyebrow) { margin-top: 20px; font-size: 15px; color: var(--muted); }
.final-actions { margin-top: 28px; display: flex; flex-wrap: wrap; justify-content: center; gap: 13px; }
.identity-footer { display: flex; gap: 35px; align-items: start; justify-content: space-between; padding-block: 37px; }
.identity-footer .brand { font-size: 23px; }
.identity-footer p { margin-top: 10px; font-size: 13px; color: var(--muted); }
.identity-footer small { display: block; margin-top: 8px; font-size: 11px; color: var(--muted); }
.identity-footer nav { display: flex; flex-wrap: wrap; justify-content: end; gap: 15px; font-size: 12px; }
.identity-footer nav a { padding-block: 6px; }
.identity-footer nav a:hover { text-decoration: underline; }
.guide-entry { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 24px; padding-block: 38px; border-top: 1px solid var(--line); }
.guide-entry h2 { margin-block: 10px 14px; font-size: 30px; }
.guide-entry p:not(.kicker) { color: var(--muted); font-size: 15px; }
@media (max-width: 1050px) {
  .wrap { width: calc(100% - 48px); }
  .header-inner { gap: 22px; }
  .header-links { gap: 17px; font-size: 13px; }
  .hero-grid { gap: 25px; padding-top: 48px; }
  .hero h1 { font-size: 50px; }
  .hero-promise { font-size: 18px; }
  .desktop-break { display: none; }
  .chapter-grid { gap: 32px; }
  .chapter-copy > .chapter-lead { font-size: 17px; }
  .takeaway strong { font-size: 22px; }
  .question-grid { gap: 23px; }
  .start-section { gap: 40px; }
}
@media (max-width: 760px) {
  :root { --header-height: 65px; }
  html { scroll-padding-top: 132px; }
  .wrap { width: calc(100% - 36px); }
  .header-links { display: none; }
  .header-inner { justify-content: space-between; gap: 12px; }
  .header-actions { gap: 8px; }
  .brand { font-size: 23px; gap: 7px; }
  .brand img { width: 24px; height: 24px; }
  .header-cta { font-size: 12px; gap: 9px; padding: 9px 11px; }
  .hero-grid { grid-template-columns: 1fr; gap: 32px; padding-block: 39px 30px; }
  .hero h1 { font-size: clamp(43px, 9.5vw, 63px); }
  .hero-promise { font-size: 19px; }
  .hero-description { max-width: 540px; }
  .hero-actions { gap: 15px; }
  .hero-visual { max-width: 600px; }
  .hero-workflow { justify-content: space-around; }
  .hero-bottom { grid-template-columns: 1fr; gap: 15px; padding-block: 23px 28px; }
  .why-section { padding-block: 44px 35px; }
  .question-grid { grid-template-columns: 1fr; gap: 24px; margin-top: 27px; }
  .question-grid article { display: grid; grid-template-columns: 30px 1fr; column-gap: 8px; padding-top: 17px; }
  .question-number { grid-row: 1 / 3; padding-top: 5px; }
  .question-grid h3 { margin: 0; font-size: 19px; }
  .question-grid p { grid-column: 2; margin-top: 8px; }
  .manifesto { padding: 18px; gap: 13px; align-items: start; }
  .manifesto > span { font-size: 24px; }
  .manifesto strong { font-size: 15px; }
  .mobile-break { display: inline; }
  .chapter-links { gap: 10px; overflow-x: auto; overscroll-behavior-x: contain; scrollbar-width: thin; }
  .chapter-links a { gap: 5px; font-size: 12px; padding-inline: 1px; min-height: 56px; }
  .chapter-links span { font-size: 10px; }
  .chapter { padding-block: 42px; }
  .chapter-heading { margin-bottom: 24px; }
  .chapter-grid { grid-template-columns: 1fr; gap: 26px; }
  .chapter-reverse .chapter-figure { order: initial; }
  .chapter-copy > .chapter-lead { font-size: 18px; }
  .benefit-list { margin-top: 18px; }
  .benefit-list dd { font-size: 15px; }
  .chapter-figure { max-width: 600px; }
  .takeaway { padding: 19px 22px 22px; }
  .takeaway strong { font-size: 24px; }
  .prompt-box { grid-template-columns: 1fr; gap: 19px; padding: 22px; }
  .prompt-content pre { font-size: 13px; }
  .start-section { grid-template-columns: 1fr; gap: 26px; padding-block: 42px; }
  .start-section .section-intro h2 { font-size: 29px; }
  .faq-section { grid-template-columns: 1fr; gap: 22px; padding-block: 36px 42px; }
  .faq-section h2 { font-size: 29px; }
  .faq-section h2 br { display: none; }
  .faq-list summary { font-size: 15px; }
  .final-cta { padding-block: 44px; }
  .final-cta h2 { font-size: clamp(29px, 6.2vw, 40px); }
  .final-cta .eyebrow { font-size: 12px; }
  .final-actions .button { width: 100%; max-width: 400px; }
  .identity-footer { flex-direction: column; gap: 23px; }
  .identity-footer nav { justify-content: start; gap: 16px; }
}
@media (max-width: 359px) {
  .wrap { width: calc(100% - 28px); }
  .brand img { display: none; }
  .brand { font-size: 22px; }
  .header-inner { gap: 6px; }
  .header-cta { padding-inline: 8px; }
  .header-cta span { display: none; }
  .hero h1 { font-size: 39px; }
  .hero-actions .button { width: 100%; }
  .hero-workflow { padding-inline: 12px; font-size: 10px; gap: 3px; }
  .chapter-heading h2 { font-size: 27px; }
  .prompt-box { padding: 17px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}