/* SF 가설노트 — 다섯 엔진 바로 위 연재 구역 (2026-10-07) */
@import url("https://fonts.googleapis.com/css2?family=Noto+Serif+KR:wght@600;700;900&display=swap");

.sfn {
  --sfn-paper: #f5f0e4;
  --sfn-ink: #17202b;
  --sfn-sub: #5b6470;
  --sfn-line: #ddd3bf;
  --sfn-green: #2f8f5b;
  --sfn-amber: #c9822b;
  --sfn-night: #0b1a2d;
  position: relative;
  background:
    radial-gradient(1200px 400px at 85% -10%, rgba(201, 130, 43, 0.10), transparent 60%),
    var(--sfn-paper);
  color: var(--sfn-ink);
  padding: clamp(44px, 6vw, 84px) max(16px, 5vw) clamp(48px, 6vw, 88px);
  border-top: 1px solid var(--sfn-line);
  overflow: hidden;
}
.sfn *, .sfn *::before, .sfn *::after { box-sizing: border-box; }
.sfn-serif { font-family: "Noto Serif KR", "Nanum Myeongjo", Georgia, serif; }

/* 머리 */
.sfn-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 18px 40px;
  padding-bottom: 22px;
  margin-bottom: clamp(26px, 3.4vw, 40px);
  border-bottom: 2px solid var(--sfn-ink);
}
.sfn-eyebrow {
  margin: 0 0 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--sfn-green);
}
.sfn-eyebrow b { color: var(--sfn-ink); }
.sfn-title {
  margin: 0;
  font-size: clamp(30px, 4.2vw, 50px);
  line-height: 1.16;
  font-weight: 900;
  letter-spacing: -0.02em;
  word-break: keep-all;
}
.sfn-title em { font-style: normal; color: var(--sfn-amber); }
.sfn-lead {
  margin: 14px 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.25vw, 17px);
  line-height: 1.7;
  color: var(--sfn-sub);
  word-break: keep-all;
}
.sfn-issue {
  text-align: right;
  font-size: 13px;
  line-height: 1.6;
  color: var(--sfn-sub);
  white-space: nowrap;
}
.sfn-issue strong {
  display: block;
  font-size: clamp(34px, 3.6vw, 46px);
  line-height: 1;
  color: var(--sfn-ink);
  font-weight: 900;
  letter-spacing: -0.02em;
}

/* 본문 2단 */
.sfn-article {
  display: grid;
  grid-template-columns: minmax(280px, 0.82fr) minmax(0, 1.5fr);
  gap: clamp(24px, 4vw, 60px);
  align-items: start;
}

/* 그림 판 */
.sfn-visual {
  position: sticky;
  top: 90px;
  margin: 0;
  border-radius: 14px;
  overflow: hidden;
  background: var(--sfn-night);
  color: #fff;
  box-shadow: 0 24px 50px -28px rgba(11, 26, 45, 0.65);
}
.sfn-visual svg { display: block; width: 100%; height: auto; aspect-ratio: 4 / 5; }
.sfn-visual figcaption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  padding: 56px 22px 20px;
  background: linear-gradient(to top, rgba(6, 14, 26, 0.92), rgba(6, 14, 26, 0));
}
.sfn-vtag {
  display: inline-block;
  margin-bottom: 8px;
  padding: 3px 9px;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: #f3d9b4;
}
.sfn-vwork { margin: 0; font-size: 20px; font-weight: 700; line-height: 1.35; }
.sfn-vmeta { margin: 4px 0 0; font-size: 13px; color: rgba(255, 255, 255, 0.7); }
.sfn-chips { display: flex; flex-wrap: wrap; gap: 6px; margin: 12px 0 0; padding: 0; list-style: none; }
.sfn-chips li {
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(47, 143, 91, 0.28);
  color: #c9f0d8;
  font-size: 12px;
}

/* 글 */
.sfn-h3 {
  margin: 0 0 6px;
  font-size: clamp(24px, 2.6vw, 34px);
  line-height: 1.3;
  font-weight: 800;
  letter-spacing: -0.015em;
  word-break: keep-all;
}
.sfn-byline { margin: 0 0 22px; font-size: 13px; color: var(--sfn-sub); }
.sfn-body { position: relative; }
.sfn-body[data-clamped="true"] { max-height: 26.5em; overflow: hidden; }
.sfn-body[data-clamped="true"]::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 7em;
  background: linear-gradient(to bottom, rgba(245, 240, 228, 0), var(--sfn-paper) 85%);
  pointer-events: none;
}
.sfn-para { margin: 0 0 1.5em; }
.sfn-label {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 8px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--sfn-green);
}
.sfn-label::after { content: ""; flex: 1; height: 1px; background: var(--sfn-line); }
.sfn-label span { color: var(--sfn-sub); font-weight: 500; letter-spacing: 0; }
.sfn-para p {
  margin: 0;
  font-size: clamp(16px, 1.2vw, 17.5px);
  line-height: 1.88;
  word-break: keep-all;
  overflow-wrap: anywhere;
}
.sfn-more {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 4px 0 0;
  padding: 10px 18px;
  border: 1.5px solid var(--sfn-ink);
  border-radius: 999px;
  background: transparent;
  color: var(--sfn-ink);
  font: inherit;
  font-size: 14.5px;
  font-weight: 700;
  cursor: pointer;
}
.sfn-more:hover { background: var(--sfn-ink); color: var(--sfn-paper); }
.sfn-more:focus-visible { outline: 3px solid var(--sfn-amber); outline-offset: 2px; }

/* 가설 */
.sfn-hyp { margin: 30px 0 0; }
.sfn-hyp-title { margin: 0 0 12px; font-size: 15px; font-weight: 800; letter-spacing: 0.02em; }
.sfn-hyp-title span { color: var(--sfn-amber); }
.sfn-hyp ol {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.sfn-hyp li {
  position: relative;
  padding: 18px 18px 18px 20px;
  border-radius: 12px;
  background: #fffdf7;
  border: 1px solid var(--sfn-line);
  border-left: 4px solid var(--sfn-amber);
  font-size: 15.5px;
  line-height: 1.65;
  font-weight: 600;
  word-break: keep-all;
}
.sfn-hyp li b {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--sfn-amber);
}

/* 엔진으로 이어지는 띠 */
.sfn-bridge {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  margin-top: clamp(30px, 4vw, 48px);
  padding: 20px 24px;
  border-radius: 14px;
  background: var(--sfn-night);
  color: #fff;
}
.sfn-bridge p { margin: 0; font-size: 15.5px; line-height: 1.6; word-break: keep-all; }
.sfn-bridge p span { color: #9fe0bb; font-weight: 700; }
.sfn-bridge a {
  flex: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: 10px;
  background: var(--sfn-green);
  color: #fff;
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
}
.sfn-bridge a:hover { background: #267a4c; }

/* 태블릿 */
@media (max-width: 960px) {
  .sfn-article { grid-template-columns: minmax(0, 1fr); }
  .sfn-visual { position: relative; top: 0; }
  .sfn-visual svg { aspect-ratio: 16 / 9; }
  .sfn-visual figcaption { position: static; padding: 16px 20px 18px; background: #081322; }
}
/* 휴대폰 */
@media (max-width: 640px) {
  .sfn-head { grid-template-columns: minmax(0, 1fr); }
  .sfn-issue { text-align: left; display: flex; align-items: baseline; gap: 10px; }
  .sfn-issue strong { display: inline; font-size: 28px; }
  .sfn-visual svg { aspect-ratio: 4 / 3; }
  .sfn-visual figcaption { padding: 14px 16px 16px; }
  .sfn-vwork { font-size: 17px; }
  .sfn-body[data-clamped="true"] { max-height: 30em; }
  .sfn-para p { font-size: 16px; line-height: 1.85; }
  .sfn-hyp ol { grid-template-columns: minmax(0, 1fr); }
  .sfn-bridge { padding: 18px; }
  .sfn-bridge a { width: 100%; justify-content: center; }
}
@media (prefers-reduced-motion: no-preference) {
  .sfn-twinkle { animation: sfn-tw 3.6s ease-in-out infinite; }
  .sfn-lens-glow { animation: sfn-pulse 4.5s ease-in-out infinite; transform-origin: center; transform-box: fill-box; }
}
@keyframes sfn-tw { 0%, 100% { opacity: 0.25; } 50% { opacity: 0.95; } }
@keyframes sfn-pulse { 0%, 100% { opacity: 0.55; transform: scale(1); } 50% { opacity: 0.95; transform: scale(1.12); } }

/* 2026-10-07 v2: 긴 헤드라인 + 부제, 구획 안 여러 문단 */
.sfn-title { font-size: clamp(26px, 3.3vw, 44px); }
.sfn-sub {
  margin: 10px 0 0;
  font-size: clamp(19px, 2vw, 26px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--sfn-amber);
  word-break: keep-all;
}
.sfn-para p + p { margin-top: 0.9em; }
.sfn-hyp li { font-weight: 500; }

/* 2026-10-07 v3: 헤드라인 줄바꿈 — PC 한 줄, 좁은 화면은 '연구개발은' 뒤에서 두 줄 */
.sfn-head { grid-template-columns: minmax(0, 1fr); }
.sfn-head > div { min-width: 0; }
.sfn-issue { justify-self: end; margin-top: -8px; }
.sfn-title { white-space: nowrap; font-size: clamp(26px, 3.8vw, 52px); }
.sfn-l1, .sfn-l2 { display: inline; }
@media (max-width: 860px) {
  .sfn-title { white-space: normal; font-size: clamp(20px, 6.5vw, 38px); }
  .sfn-l1, .sfn-l2 { display: block; white-space: nowrap; }
  .sfn-issue { justify-self: start; margin-top: 0; }
}

/* 2026-10-07 v4: 오늘의 연구질문(기본 1개) + 이어서 해 보기 */
.sfn-hyp-one ol { grid-template-columns: minmax(0, 1fr); }
.sfn-hyp-one li { font-size: clamp(16.5px, 1.35vw, 19px); line-height: 1.6; padding: 20px 22px 20px 24px; }
.sfn-next {
  margin: 12px 0 0;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--sfn-sub);
  word-break: keep-all;
}
.sfn-next-tag {
  display: inline-block;
  margin-right: 4px;
  padding: 1px 8px;
  border-radius: 999px;
  background: rgba(47, 143, 91, 0.12);
  color: var(--sfn-green);
  font-size: 12.5px;
  font-weight: 700;
}
.sfn-next a { color: var(--sfn-green); font-weight: 700; text-decoration: none; white-space: nowrap; }
.sfn-next a:hover { text-decoration: underline; }