/* IB Wiki 랜딩 — 사이트의 나머지 페이지(Toss 톤, flat, blue accent)와 의도적으로 다른 브랜드.
   "IB 전용 AI"라는 독립 서비스임을 시각적으로도 분리하기 위해 dark-hero → black-void → light-surface
   3단 리듬의 별도 디자인 시스템을 얹는다. 참고: Scale AI 스타일 가이드(사용자 제공).
   Aeonik/Mono는 라이선스 문제로 Inter/JetBrains Mono로 대체. */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500&display=swap');

.iw-page {
  --iw-white: #ffffff;
  --iw-black: #000000;
  --iw-mist: #f2f2f2;
  --iw-stone: #eaeaea;
  --iw-bone: #e5e5e5;
  --iw-graphite: #575757;
  --iw-smoke: #929292;
  --iw-charcoal: #212121;
  --iw-silhouette: #c7c7c7;
  --iw-sandstone: #a8927c;
  --iw-forest: #193a29;
  --iw-iris: #79648c;
  --iw-slate: #839cb2;
  --iw-font: 'Inter', var(--font-body);
  --iw-mono: 'JetBrains Mono', ui-monospace, monospace;
  font-family: var(--iw-font);
  color: var(--iw-black);
  background: var(--iw-white);
}
.iw-page * { font-family: inherit; }
.iw-page section { padding: 0; }
.iw-page .container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }

/* ---------- 1. Hero: full-bleed dark photographic frame ---------- */
.iw-hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse at 30% 20%, rgba(131,156,178,.25), transparent 55%),
    radial-gradient(ellipse at 75% 75%, rgba(121,100,140,.22), transparent 55%),
    #05070a;
}
.iw-hero-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at center, black 0%, transparent 72%);
}
.iw-hero-inner { position: relative; z-index: 1; padding: 40px 24px; max-width: 900px; }
.iw-hero h1 {
  font-family: var(--iw-font); font-weight: 400; color: #fff;
  font-size: clamp(30px, 4.4vw, 56px); line-height: 1.15; letter-spacing: -0.02em;
  margin-bottom: 24px;
}
.iw-hero .sub {
  font-size: clamp(15px, 1.6vw, 20px); font-weight: 400; line-height: 1.6;
  color: rgba(255,255,255,.72); max-width: 46ch; margin: 0 auto 40px;
}
.iw-hero .cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.iw-btn-light {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; color: #000; border: none; border-radius: 8px;
  font-size: 17.5px; font-weight: 500; padding: 14px 26px; text-decoration: none;
  transition: transform .15s ease, background .15s ease;
}
.iw-btn-light:hover { background: #eaeaea; transform: translateY(-1px); }
.iw-btn-ghost {
  display: inline-flex; align-items: center; gap: 8px;
  background: transparent; color: #fff; border: 1px solid rgba(255,255,255,.3); border-radius: 8px;
  font-size: 17.5px; font-weight: 400; padding: 14px 26px; text-decoration: none;
  transition: border-color .15s ease, background .15s ease;
}
.iw-btn-ghost:hover { border-color: rgba(255,255,255,.6); background: rgba(255,255,255,.06); }
.iw-scroll-prompt {
  position: absolute; right: 28px; bottom: 28px; z-index: 1;
  display: flex; align-items: center; gap: 10px; color: rgba(255,255,255,.55);
}
.iw-scroll-prompt span { font-family: var(--iw-mono); font-size: 14.5px; }
.iw-scroll-prompt .box {
  width: 40px; height: 40px; border: 1px solid rgba(255,255,255,.35); border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  animation: iw-bounce 1.8s ease-in-out infinite;
}
@keyframes iw-bounce { 0%,100% { transform: translateY(0); } 50% { transform: translateY(5px); } }
@media (max-width: 640px) { .iw-scroll-prompt { display: none; } }

/* ---------- 2. Black void: wireframe statement ---------- */
.iw-page .iw-void {
  background: #000; color: #fff;
  padding: 160px 24px 180px;
  text-align: center;
}
.iw-void-diagram { max-width: 640px; margin: 0 auto 56px; }
.iw-void-diagram svg { width: 100%; height: auto; display: block; }
/* 선을 따라 점선이 흘러가는 느낌 + 노드가 은은하게 펄스, 중심에서 각 노드로 작은 점이 실제로 이동 */
.iw-flow-line { stroke-dasharray: 5 7; animation: iw-flow 2.4s linear infinite; }
@keyframes iw-flow { to { stroke-dashoffset: -24; } }
.iw-pulse-node { animation: iw-pulse 2.4s ease-in-out infinite; transform-origin: center; transform-box: fill-box; }
@keyframes iw-pulse { 0%, 100% { transform: scale(1); opacity: 1; } 50% { transform: scale(1.12); opacity: .7; } }
@media (prefers-reduced-motion: reduce) {
  .iw-flow-line, .iw-pulse-node { animation: none; }
  .iw-void-diagram animateMotion { display: none; }
}
.iw-void-list { list-style: none; max-width: 60ch; margin: 0 auto; text-align: left; }
.iw-void-list li {
  position: relative; padding-left: 26px; margin-top: 16px;
  font-size: clamp(16px, 1.8vw, 19px); line-height: 1.6; font-weight: 400; color: #fff;
}
.iw-void-list li:first-child { margin-top: 0; }
.iw-void-list li::before {
  content: ''; position: absolute; left: 0; top: 9px;
  width: 6px; height: 6px; border-radius: 50%; background: var(--iw-slate);
}
.iw-void-list li strong { color: var(--iw-slate); font-weight: 600; }

/* ---------- 3. Light product surface ---------- */
.iw-page .iw-surface { background: #fff; padding: 140px 24px; }
.iw-surface.mist { background: var(--iw-mist); }
.iw-section-head { max-width: 640px; margin: 0 auto 56px; text-align: center; }
.iw-section-head .label {
  font-family: var(--iw-mono); font-size: 12.5px; letter-spacing: .55px; text-transform: uppercase;
  color: var(--iw-graphite); display: block; margin-bottom: 16px;
}
.iw-section-head h2 {
  font-family: var(--iw-font); font-weight: 400; color: #000;
  font-size: clamp(26px, 3.4vw, 40px); letter-spacing: -0.02em; line-height: 1.2;
}
.iw-section-head p { margin-top: 14px; font-size: 17.5px; color: var(--iw-graphite); line-height: 1.6; }

/* 둥근 카드 그리드 대신, 기술 사양서 느낌의 flat한 번호 목록 — mono 인덱스 + 구분선만으로 위계를 만든다 */
.iw-feature-list { max-width: 880px; margin: 0 auto; border-top: 1px solid var(--iw-bone); }
.iw-feature-row {
  display: grid; grid-template-columns: 56px 200px 1fr; align-items: baseline; gap: 24px;
  padding: 28px 0; border-bottom: 1px solid var(--iw-bone);
}
.iw-feature-row .idx { font-family: var(--iw-mono); font-size: 14.5px; color: var(--iw-smoke); }
.iw-feature-row h4 { font-weight: 500; font-size: 18.5px; letter-spacing: -0.01em; }
.iw-feature-row p { font-size: 15.5px; color: var(--iw-graphite); line-height: 1.6; }
@media (max-width: 700px) {
  .iw-feature-row { grid-template-columns: 40px 1fr; }
  .iw-feature-row p { grid-column: 2; }
}

/* Chat preview card */
.iw-chat-wrap { max-width: 640px; margin: 0 auto; }
.iw-chat-card { background: #fff; border: 1px solid var(--iw-bone); border-radius: 16px; padding: 32px; }
.iw-chat-bubble { border-radius: 12px; padding: 14px 18px; font-size: 16px; line-height: 1.6; max-width: 88%; }
.iw-chat-bubble + .iw-chat-bubble { margin-top: 14px; }
.iw-chat-bubble.user { background: var(--iw-mist); margin-left: auto; color: #000; }
.iw-chat-bubble.ai { background: var(--iw-black); color: #fff; max-width: 100%; padding: 22px 24px; }
.iw-chat-bubble .source {
  display: block; margin-top: 18px; font-family: var(--iw-mono); font-size: 12.5px;
  color: rgba(255,255,255,.55);
}

/* AI 답변을 "줄글"이 아니라 Key concept / Common pattern / Exam tip 섹션으로 나눠서 보여줌 */
.iw-chat-block + .iw-chat-block { margin-top: 18px; }
.iw-chat-label {
  display: block; font-family: var(--iw-mono); font-size: 12px; letter-spacing: .55px;
  text-transform: uppercase; color: var(--iw-slate); margin-bottom: 6px;
}
.iw-chat-block p { margin: 0; color: rgba(255,255,255,.92); }
.iw-chat-block ul { margin: 0; padding-left: 18px; color: rgba(255,255,255,.92); }
.iw-chat-block li + li { margin-top: 6px; }
.iw-chat-block strong { color: #fff; font-weight: 600; }

/* 마지막 CTA — hero/CTA의 둥근 pill 버튼과 의도적으로 다른, 각진 직사각형 */
.iw-btn-rect {
  display: inline-flex; align-items: center; gap: 8px;
  background: #000; color: #fff; border: none; border-radius: 0;
  font-size: 17.5px; font-weight: 500; padding: 16px 32px; text-decoration: none;
  transition: opacity .15s ease;
}
.iw-btn-rect:hover { opacity: .8; }