/* =========================================================
   멘피디(서진원) 개인 홈페이지 — Apple 스타일 디자인 시스템
   White room + single blue switch
   ========================================================= */

:root {
  /* Colors */
  --color-apple-blue: #0071e3;
  --color-link-blue: #0066cc;
  --color-signal-blue: #2997ff;
  --color-carbon: #1d1d1f;
  --color-frost: #f5f5f7;
  --color-ice: #f4f8fb;
  --color-smoke: #333333;
  --color-graphite: #474747;
  --color-ash: #707070;
  --color-mist: #858585;
  --color-onyx: #000000;
  --color-pebble: #e2e2e5;
  --color-hairline: #d2d2d7;

  /* Kakao 브랜드 컬러 — 플로팅 문의 버튼 전용 (카카오톡 인지성을 위해 예외적으로 사용) */
  --color-kakao: #fee500;
  --color-kakao-text: #3c1e1e;

  /* Typography */
  --font-display: 'SF Pro Display', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-text: 'SF Pro Text', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Spacing */
  --spacing-4: 4px;
  --spacing-8: 8px;
  --spacing-12: 12px;
  --spacing-16: 16px;
  --spacing-20: 20px;
  --spacing-24: 24px;
  --spacing-40: 40px;
  --spacing-48: 48px;
  --spacing-56: 56px;

  /* Layout */
  --page-max-width: 1440px;
  --text-max-width: 980px;
  --section-gap: 64px;

  /* Radius */
  --radius-cards: 8px;
  --radius-buttons: 980px;

  /* Shadow — 제품(이미지) 전용, 카드/버튼에는 사용하지 않음 */
  --shadow-xl: rgba(0, 0, 0, 0.22) 3px 5px 30px 0px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-text);
  font-size: 17px;
  line-height: 1.47;
  letter-spacing: -0.272px;
  color: var(--color-carbon);
  background: var(--color-frost);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
}

section {
  padding: var(--section-gap) var(--spacing-24);
}

.section-inner {
  max-width: var(--page-max-width);
  margin: 0 auto;
}

.text-col {
  max-width: var(--text-max-width);
}

.eyebrow {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.224px;
  color: var(--color-apple-blue);
  text-transform: uppercase;
  margin: 0 0 var(--spacing-12);
}

.section-heading {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 600;
  line-height: 1.14;
  letter-spacing: 0.44px;
  margin: 0 0 var(--spacing-16);
  color: var(--color-carbon);
}

.section-sub {
  font-size: 21px;
  font-weight: 300;
  line-height: 1.24;
  letter-spacing: -0.105px;
  color: var(--color-graphite);
  margin: 0 0 var(--spacing-40);
  max-width: 640px;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-8);
  border-radius: var(--radius-buttons);
  padding: 11px 22px;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: -0.272px;
  cursor: pointer;
  border: none;
  transition: opacity 0.15s ease, background-color 0.15s ease;
  white-space: nowrap;
}

.btn-filled {
  background: var(--color-apple-blue);
  color: #ffffff;
}

.btn-filled:hover {
  background: #0077ed;
}

.btn-outline {
  background: transparent;
  border: 1px solid var(--color-link-blue);
  color: var(--color-link-blue);
}

.btn-outline:hover {
  background: rgba(0, 102, 204, 0.06);
}

.btn-ghost {
  background: transparent;
  color: var(--color-link-blue);
  padding: 11px 4px;
}

.btn-ghost:hover {
  text-decoration: underline;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 14px;
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* ---------- Nav ---------- */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-carbon);
  border-bottom: 1px solid var(--color-smoke);
}

.nav-inner {
  max-width: var(--page-max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px var(--spacing-24);
}

.nav-brand {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-frost);
  letter-spacing: -0.224px;
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.nav-brand span {
  font-weight: 400;
  color: var(--color-mist);
  font-size: 12px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-24);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  font-size: 12px;
  font-weight: 400;
  color: var(--color-frost);
  letter-spacing: -0.264px;
}

.nav-links a:hover {
  color: var(--color-signal-blue);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: var(--spacing-16);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-frost);
  font-size: 22px;
  cursor: pointer;
  padding: 4px 8px;
}

/* ---------- Hero ---------- */

.hero {
  display: flex;
  align-items: stretch;
  padding: 0;
  background: var(--color-frost);
}

.hero-portrait {
  flex: 0 0 42%;
  min-width: 0;
  align-self: flex-start;
  max-height: 760px;
}

.hero-portrait .media-frame {
  width: 100%;
  height: 100%;
  border-radius: 0;
  box-shadow: none;
}

.hero-portrait .media-frame img {
  object-position: center 15%;
}

.hero-content {
  flex: 1;
  max-width: 860px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: var(--spacing-56);
}

.hero-kicker {
  font-size: 19px;
  font-weight: 400;
  color: var(--color-graphite);
  margin: 0 0 var(--spacing-16);
}

.hero-headline {
  font-family: var(--font-display);
  font-size: 56px;
  font-weight: 600;
  line-height: 1.07;
  letter-spacing: 0.616px;
  margin: 0 0 var(--spacing-24);
  color: var(--color-carbon);
}

.hero-bio {
  font-size: 17px;
  color: var(--color-smoke);
  max-width: 620px;
  margin: 0 0 var(--spacing-24);
}

/* ---------- Contact block ---------- */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-16);
}

.contact-card {
  display: block;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  padding: var(--spacing-16);
  background: #ffffff;
  min-height: 128px;
}

.contact-card .contact-icon {
  width: 22px;
  height: 22px;
  color: var(--color-apple-blue);
  margin-bottom: var(--spacing-8);
}

.contact-card .contact-label {
  font-size: 12px;
  color: var(--color-ash);
  margin: 0 0 4px;
}

.contact-card .contact-value {
  font-size: 14px;
  color: var(--color-carbon);
  font-weight: 400;
  word-break: break-all;
}

.contact-card a.contact-value:hover {
  color: var(--color-link-blue);
}

.contact-value-muted {
  color: var(--color-mist);
  font-style: italic;
}

/* ---------- Contact card flip (email / phone) ---------- */

.contact-card-flip {
  padding: 0;
  cursor: pointer;
  perspective: 1000px;
}

.contact-card-flip .flip-inner {
  position: relative;
  width: 100%;
  min-height: 128px;
  transition: transform 0.6s cubic-bezier(0.25, 0.1, 0.25, 1);
  transform-style: preserve-3d;
}

.contact-card-flip.flipped .flip-inner {
  transform: rotateY(180deg);
}

.contact-card-flip .flip-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  padding: var(--spacing-16);
  display: flex;
  flex-direction: column;
}

.contact-card-flip .flip-back {
  transform: rotateY(180deg);
  align-items: center;
  justify-content: center;
  text-align: center;
}

.contact-card-flip .flip-back .contact-value {
  word-break: break-word;
}

/* ---------- Media frame / image fallback ---------- */

.media-frame {
  position: relative;
  background: var(--color-pebble);
  border-radius: var(--radius-cards);
  overflow: hidden;
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame.img-missing::after {
  content: attr(data-label);
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-16);
  font-size: 12px;
  line-height: 1.4;
  color: var(--color-ash);
  background: var(--color-pebble);
}

.media-frame.img-missing::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23a1a1a6' stroke-width='1.2'%3E%3Crect x='3' y='5' width='18' height='14' rx='2'/%3E%3Ccircle cx='9' cy='11' r='2'/%3E%3Cpath d='M21 16l-5-5-4 4-3-3-5 5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center 28%;
  background-size: 40px;
  opacity: 0.7;
}

/* ---------- Book section ---------- */

.book-section {
  background: var(--color-ice);
}

.book-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-56);
  align-items: center;
}

.book-covers {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: var(--spacing-16);
  align-items: end;
}

.book-cover-main .media-frame {
  aspect-ratio: 3 / 4;
  box-shadow: var(--shadow-xl);
}

.book-cover-sub .media-frame {
  aspect-ratio: 3 / 4;
  box-shadow: var(--shadow-xl);
}

.book-info h3 {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  letter-spacing: 0.196px;
  margin: 0 0 var(--spacing-12);
}

.book-info h3 .book-year {
  font-family: var(--font-text);
  font-size: 17px;
  font-weight: 300;
  color: var(--color-ash);
  letter-spacing: -0.272px;
}

.book-info p {
  color: var(--color-smoke);
  margin: 0 0 var(--spacing-24);
}

.book-highlights {
  list-style: none;
  margin: 0 0 var(--spacing-24);
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-12);
}

.book-highlights li {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-12);
  font-size: 14px;
  color: var(--color-smoke);
}

.book-highlights svg {
  flex: none;
  width: 18px;
  height: 18px;
  margin-top: 1px;
  color: var(--color-signal-blue);
}

.book-meta {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--spacing-24);
  border-top: 1px solid var(--color-hairline);
}

.book-meta li {
  display: flex;
  justify-content: space-between;
  padding: var(--spacing-12) 0;
  border-bottom: 1px solid var(--color-hairline);
  font-size: 14px;
}

.book-meta li span:first-child {
  color: var(--color-ash);
}

.book-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-16);
}

/* ---------- Video section ---------- */

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-24);
}

.video-card {
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  overflow: hidden;
  background: #ffffff;
}

.video-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background: var(--color-carbon);
}

.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.video-caption {
  padding: var(--spacing-16);
}

.video-caption h4 {
  font-size: 17px;
  font-weight: 600;
  margin: 0 0 4px;
}

.video-caption p {
  font-size: 14px;
  color: var(--color-ash);
  margin: 0;
}

/* ---------- Resources section ---------- */

.resource-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-24);
  align-items: start;
}

.resource-col {
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  background: #ffffff;
  padding: var(--spacing-24);
}

.resource-col-badge {
  display: inline-block;
  background: var(--color-carbon);
  color: #ffffff;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: -0.224px;
  padding: 4px 14px;
  border-radius: var(--radius-buttons);
  margin-bottom: var(--spacing-16);
}

.resource-col-badge.badge-locked {
  background: var(--color-mist);
}

.resource-col-desc {
  font-size: 14px;
  color: var(--color-ash);
  margin: 0 0 var(--spacing-20);
}

.resource-col .resource-list {
  grid-template-columns: 1fr;
}

.resource-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-16);
}

.resource-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-12);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  padding: var(--spacing-16);
  background: #ffffff;
}

.resource-item .res-icon {
  width: 32px;
  height: 32px;
  flex: none;
  color: var(--color-apple-blue);
}

.resource-item .res-icon.locked {
  color: var(--color-mist);
}

.resource-item .res-body {
  flex: 1;
  min-width: 0;
}

.resource-item .res-title {
  font-size: 14px;
  font-weight: 400;
  color: var(--color-carbon);
  margin: 0 0 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.resource-item .res-meta {
  font-size: 12px;
  color: var(--color-ash);
  margin: 0;
}

.gate-box {
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  background: #ffffff;
  padding: var(--spacing-24);
  max-width: 460px;
}

.gate-box p {
  font-size: 14px;
  color: var(--color-ash);
  margin: 0 0 var(--spacing-16);
}

.gate-form {
  display: flex;
  gap: var(--spacing-12);
}

.gate-input {
  flex: 1;
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  padding: 11px 15px;
  font-size: 14px;
  background: var(--color-frost);
  color: var(--color-carbon);
}

.gate-input:focus {
  outline: 2px solid var(--color-apple-blue);
  outline-offset: 1px;
  background: #ffffff;
}

.gate-message {
  font-size: 12px;
  margin-top: var(--spacing-12);
  min-height: 16px;
}

.gate-message.error {
  color: #d70015;
}

.gate-message.success {
  color: #1a7d3a;
}

.resource-list[hidden] {
  display: none;
}

.gate-unlocked .resource-list {
  margin-top: var(--spacing-16);
}

.gate-unlocked .gate-box {
  display: none;
}

/* ---------- Reviews section ---------- */

.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-24);
  margin-bottom: var(--spacing-56);
}

.review-card {
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-cards);
  padding: var(--spacing-24);
  background: #ffffff;
  display: flex;
  flex-direction: column;
}

.review-quote {
  font-size: 17px;
  color: var(--color-carbon);
  margin: 0 0 var(--spacing-24);
  flex: 1;
}

.review-org {
  display: flex;
  align-items: center;
  gap: var(--spacing-12);
  padding-top: var(--spacing-16);
  border-top: 1px solid var(--color-hairline);
}

.review-org-name {
  font-size: 14px;
  font-weight: 600;
  margin: 0;
}

.review-org-role {
  font-size: 12px;
  color: var(--color-ash);
  margin: 0;
}

.portfolio-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-16);
}

.portfolio-grid .media-frame {
  aspect-ratio: 4 / 3;
}

/* ---------- Footer ---------- */

.site-footer {
  background: var(--color-frost);
  border-top: 1px solid var(--color-hairline);
  padding: var(--spacing-48) var(--spacing-24) var(--spacing-24);
}

.footer-inner {
  max-width: var(--page-max-width);
  margin: 0 auto;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: var(--spacing-24);
  padding-bottom: var(--spacing-24);
  border-bottom: 1px solid var(--color-hairline);
}

.footer-brand {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-carbon);
}

.footer-brand p {
  font-size: 12px;
  font-weight: 400;
  color: var(--color-ash);
  margin: 4px 0 0;
}

.footer-links {
  display: flex;
  gap: var(--spacing-40);
}

.footer-col h5 {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-carbon);
  margin: 0 0 var(--spacing-12);
}

.footer-col a,
.footer-col p {
  display: block;
  font-size: 12px;
  color: var(--color-ash);
  margin: 0 0 var(--spacing-8);
}

.footer-col a:hover {
  color: var(--color-link-blue);
}

.footer-fine {
  font-size: 12px;
  color: var(--color-ash);
  padding-top: var(--spacing-16);
}

/* ---------- Floating KakaoTalk CTA ---------- */

.kakao-float {
  position: fixed;
  right: var(--spacing-24);
  bottom: var(--spacing-24);
  z-index: 200;
  display: flex;
  align-items: center;
  gap: var(--spacing-8);
  background: var(--color-kakao);
  color: var(--color-kakao-text);
  border-radius: var(--radius-buttons);
  padding: 12px 20px 12px 14px;
  font-size: 14px;
  font-weight: 600;
  box-shadow: rgba(0, 0, 0, 0.18) 0px 4px 18px 0px;
  transition: transform 0.15s ease;
}

.kakao-float:hover {
  transform: translateY(-2px);
}

.kakao-float svg {
  width: 22px;
  height: 22px;
}

/* ---------- Responsive ---------- */

@media (max-width: 900px) {
  .hero {
    flex-direction: column;
  }

  .hero-portrait {
    flex: none;
    width: 100%;
    height: 340px;
  }

  .hero-content {
    max-width: none;
    padding: var(--spacing-40) var(--spacing-24);
  }

  .book-layout {
    grid-template-columns: 1fr;
  }

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

  .footer-top {
    flex-direction: column;
  }

  .footer-links {
    gap: var(--spacing-24);
    flex-wrap: wrap;
  }
}

@media (max-width: 720px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav.open .nav-links {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-16);
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-carbon);
    padding: var(--spacing-24);
    border-bottom: 1px solid var(--color-smoke);
  }

  .hero-headline {
    font-size: 40px;
  }

  .hero-portrait {
    height: 260px;
  }

  .section-heading {
    font-size: 28px;
  }

  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }

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

  .gate-form {
    flex-direction: column;
  }

  .resource-columns {
    grid-template-columns: none;
    grid-auto-flow: column;
    grid-auto-columns: 86%;
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    padding-bottom: var(--spacing-8);
    -webkit-overflow-scrolling: touch;
  }

  .resource-col {
    scroll-snap-align: start;
  }

  .kakao-float span {
    display: none;
  }

  .kakao-float {
    padding: 14px;
  }
}

/* ---------- Scroll reveal ---------- */

.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s cubic-bezier(0.25, 0.1, 0.25, 1),
              transform 0.6s cubic-bezier(0.25, 0.1, 0.25, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s cubic-bezier(0.25, 0.1, 0.25, 1),
              transform 0.5s cubic-bezier(0.25, 0.1, 0.25, 1);
}

.reveal-stagger.is-visible > * {
  opacity: 1;
  transform: translateY(0);
}

.reveal-stagger.is-visible > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger.is-visible > *:nth-child(2) { transition-delay: 70ms; }
.reveal-stagger.is-visible > *:nth-child(3) { transition-delay: 140ms; }
.reveal-stagger.is-visible > *:nth-child(4) { transition-delay: 210ms; }
.reveal-stagger.is-visible > *:nth-child(5) { transition-delay: 280ms; }
.reveal-stagger.is-visible > *:nth-child(6) { transition-delay: 350ms; }

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .reveal-stagger > * {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .contact-card-flip .flip-inner {
    transition: none !important;
  }
}