:root {
  /* [색상] 기본 배경색 */
  --bg: #f7f3ff;
  --bg-2: #eef7ff;
  
  /* [UI 요소] 투명한 카드/패널 배경색 */
  --surface: rgba(255, 255, 255, 0.68);
  --surface-strong: rgba(255, 255, 255, 0.86);
  --surface-fallback: #ffffff;
  
  /* [테두리] 선 색상 */
  --border: rgba(87, 72, 119, 0.18);
  --border-strong: rgba(95, 76, 142, 0.32);
  
  /* [포인트 컬러] 보라색 테마 */
  --accent: #a78bfa;
  --accent-strong: #7c3aed;
  --accent-soft: rgba(167, 139, 250, 0.24);
  --accent-glow: rgba(167, 139, 250, 0.36);
  
  /* [텍스트] 글자 색상 */
  --text: #171321;
  --text-muted: #574f63;
  --text-subtle: #6d6578;
  
  /* [효과] 그림자와 둥글기 */
  --shadow: 0 28px 80px rgba(65, 49, 96, 0.18);
  --inner-light: rgba(255, 255, 255, 0.72);
  --radius: 28px; /* 큰 패널의 모서리 둥글기 */
  --radius-sm: 18px; /* 작은 버튼/입력창의 모서리 둥글기 */
  color-scheme: light;
}

:root[data-theme="dark"] {
  --bg: #071818;
  --bg-2: #0d1f28;
  --surface: rgba(9, 31, 34, 0.68);
  --surface-strong: rgba(14, 45, 48, 0.84);
  --surface-fallback: #0b2023;
  --border: rgba(99, 255, 225, 0.16);
  --border-strong: rgba(94, 234, 212, 0.36);
  --accent: #5eead4;
  --accent-strong: #2dd4bf;
  --accent-soft: rgba(45, 212, 191, 0.18);
  --accent-glow: rgba(45, 212, 191, 0.28);
  --text: #f0fffb;
  --text-muted: #b9d8d5;
  --text-subtle: #91b9b5;
  --shadow: 0 30px 90px rgba(0, 0, 0, 0.42);
  --inner-light: rgba(255, 255, 255, 0.15);
  color-scheme: dark;
}

:root[data-theme="high-contrast"] {
  --bg: #000000;
  --bg-2: #000000;
  --surface: #000000;
  --surface-strong: #000000;
  --surface-fallback: #000000;
  --border: #ffffff;
  --border-strong: #fff86b;
  --accent: #fff86b;
  --accent-strong: #fff200;
  --accent-soft: #222200;
  --accent-glow: transparent;
  --text: #ffffff;
  --text-muted: #ffffff;
  --text-subtle: #f5f5f5;
  --shadow: none;
  --inner-light: transparent;
  --radius: 14px;
  --radius-sm: 10px;
  color-scheme: dark;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  margin: 0;
  /* [폰트] 전체 글꼴 설정 */
  font-family: "Pretendard", "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", system-ui, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 12% 12%, var(--accent-glow), transparent 28rem),
    radial-gradient(circle at 82% 8%, rgba(125, 211, 252, 0.18), transparent 24rem),
    linear-gradient(135deg, var(--bg) 0%, var(--bg-2) 100%);
  line-height: 1.6; /* [줄간격] 본문 텍스트의 상하 간격 */
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.14) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.7), transparent 72%);
}

a {
  color: inherit;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1rem;
  align-items: center;
  width: min(1180px, calc(100% - 32px)); /* [헤더 너비] 상단 바의 최대 가로 길이 */
  min-height: 72px; /* [헤더 높이] 상단 바의 최소 높이 */
  margin: 16px auto 0; /* [상단 여백] 웹페이지 맨 위에서 헤더까지의 거리 */
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 999px; /* 완전 둥근 형태 */
  background: var(--surface);
  box-shadow: 0 18px 50px rgba(31, 27, 45, 0.1);
}

.brand,
.top-nav,
.theme-switcher,
.hero-actions,
.download-actions,
.manual-links {
  display: flex;
  align-items: center;
}

.brand {
  gap: 0.55rem;
  min-width: max-content;
  font-weight: 800;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 2.25rem;
  height: 2.25rem;
  place-items: center;
  border: 1px solid var(--border-strong);
  border-radius: 50%;
  background: var(--accent-soft);
}

.top-nav {
  justify-content: center;
  gap: 1.15rem;
}

.top-nav a {
  color: var(--text-muted);
  font-size: 0.94rem; /* [메뉴 폰트] 상단 메뉴 글자 크기 */
  font-weight: 700;
  text-decoration: none;
}

.top-nav a:hover,
.top-nav a:focus-visible {
  color: var(--text);
}

.theme-switcher {
  gap: 0.55rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 700;
}

.theme-select {
  min-width: 104px;
  padding: 0.48rem 2rem 0.48rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  appearance: none;
  color: var(--text);
  background:
    linear-gradient(45deg, transparent 50%, var(--text-muted) 50%),
    linear-gradient(135deg, var(--text-muted) 50%, transparent 50%),
    var(--surface-strong);
  background-position:
    calc(100% - 15px) calc(50% - 2px),
    calc(100% - 10px) calc(50% - 2px),
    0 0;
  background-repeat: no-repeat;
  background-size: 5px 5px, 5px 5px, auto;
  font: inherit;
}

.section-shell {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(420px, 1.18fr);
  gap: 2.5rem;
  align-items: center;
  padding: clamp(3.5rem, 7vw, 6rem) 0 4rem;
}

.hero-copy {
  max-width: 620px;
}

.eyebrow {
  margin: 0 0 0.8rem;
  color: var(--accent-strong);
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3,
.eyebrow,
.button,
.top-nav a {
  word-break: keep-all;
  overflow-wrap: normal;
}

h1 {
  margin-bottom: 1.25rem;
  font-size: clamp(2.15rem, 3.7vw, 3.8rem); /* [제목 크기] 화면 너비에 따라 2.15~3.8rem 사이로 조절됨 */
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0.8rem;
  font-size: clamp(1.8rem, 3vw, 3rem); /* [소제목 크기] 화면 너비에 따라 1.8~3rem 사이로 조절됨 */
  line-height: 1.12;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 0.55rem;
  font-size: 1.15rem; /* [작은 제목 크기] */
}

.hero-lead {
  max-width: 34rem;
  margin-bottom: 1.8rem;
  color: var(--text-muted);
  font-size: 1.08rem; /* [설명 텍스트 크기] 메인 제목 아래 문구의 크기 */
}

.hero-actions,
.download-actions {
  flex-wrap: wrap;
  gap: 0.8rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px; /* [버튼 높이] */
  padding: 0.78rem 1.15rem; /* [버튼 안쪽 여백] 상하 0.78rem, 좌우 1.15rem */
  border: 1px solid var(--border-strong);
  border-radius: 999px; /* [버튼 둥글기] 999px는 알약 모양 */
  font-weight: 850;
  text-decoration: none;
}

.button.primary {
  color: #ffffff;
  background: linear-gradient(135deg, var(--accent-strong), var(--accent));
  border-color: transparent;
  box-shadow: 0 16px 36px var(--accent-glow);
}

:root[data-theme="high-contrast"] .button.primary {
  color: #000000;
  background: var(--accent);
  box-shadow: none;
}

.button.secondary,
.button.ghost {
  color: var(--text);
  background: var(--surface-strong);
}

.button.ghost {
  background: transparent;
}

.glass-panel {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-fallback);
  box-shadow: var(--shadow); /* [그림자] 패널의 입체감을 주는 그림자 */
}

@supports ((backdrop-filter: blur(22px)) or (-webkit-backdrop-filter: blur(22px))) {
  .site-header,
  .glass-panel {
    background: var(--surface);
    -webkit-backdrop-filter: blur(24px) saturate(1.45);
    backdrop-filter: blur(24px) saturate(1.45);
  }
}

.glass-panel::before {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  content: "";
  background:
    linear-gradient(135deg, var(--inner-light), transparent 42%),
    radial-gradient(circle at 86% 18%, var(--accent-soft), transparent 32%);
}

.glass-panel > * {
  position: relative;
  z-index: 1;
}

.hero-visual {
  margin: 0;
  padding: 1rem;
}

.hero-visual img,
.screenshot-card img {
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius) - 12px);
  object-fit: contain;
}

figcaption {
  margin-top: 0.75rem;
  color: var(--text-subtle);
  font-size: 0.92rem;
  font-weight: 700;
}

.quick-guide,
.showcase,
.video-section,
.manual,
.faq,
.download {
  padding: 3.25rem 0; /* [섹션 간격] 각 섹션(가이드, 쇼케이스 등)의 위아래 여백 */
}

.section-heading {
  max-width: 640px;
  margin-bottom: 1.35rem;
}

.section-heading p:last-child,
.manual-panel p,
.download-panel p {
  color: var(--text-muted);
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.guide-card {
  min-height: 220px;
  padding: 1.35rem;
}

.step-number {
  display: grid;
  width: 2.4rem;
  height: 2.4rem;
  margin-bottom: 1.2rem;
  place-items: center;
  border: 1px solid var(--border-strong);
  border-radius: 50%;
  color: var(--accent-strong);
  background: var(--accent-soft);
  font-weight: 900;
}

.guide-card p,
.download-panel p,
.manual-panel p {
  margin-bottom: 0;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
}

.screenshot-card {
  display: grid;
  grid-template-rows: minmax(360px, 1fr) auto;
  margin: 0;
  padding: 1.15rem;
}

.screenshot-card.wide-screen {
  grid-column: 1 / -1;
  grid-template-rows: auto auto;
}

.screenshot-card img {
  width: 100%;
  height: 360px;
  background: var(--surface-strong);
  object-fit: contain;
  object-position: top center;
}

.screenshot-card.wide-screen img {
  height: auto;
}

.video-frame {
  padding: 1rem;
}

.video-frame iframe {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  border-radius: calc(var(--radius) - 12px);
  background: #000000;
}

.manual-panel,
.download-panel {
  padding: clamp(1.5rem, 4vw, 3rem);
}

.faq-panel {
  padding: clamp(1.5rem, 4vw, 3rem);
}

.faq-list {
  display: grid;
  gap: 0.9rem;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: calc(var(--radius-sm) + 2px);
  background: var(--surface-strong);
  overflow: hidden;
}

.faq-summary {
  position: relative;
  display: block;
  padding: 1rem 3.25rem 1rem 1.1rem;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 850;
  line-height: 1.45;
  list-style: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary::after {
  position: absolute;
  top: 50%;
  right: 1.1rem;
  transform: translateY(-50%);
  content: "+";
  color: var(--accent-strong);
  font-size: 1.35rem;
  font-weight: 700;
}

.faq-item[open] .faq-summary::after {
  content: "−";
}

.faq-answer {
  padding: 0 1.1rem 1.1rem;
  color: var(--text-muted);
}

.faq-answer p:last-child,
.faq-footer {
  margin-bottom: 0;
}

.faq-footer {
  margin-top: 1.2rem;
  color: var(--text-muted);
}

.subpage-main {
  padding: 2rem 0 4rem;
}

.feedback-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
  gap: 1.25rem;
  align-items: start;
}

.feedback-intro,
.feedback-form-panel {
  padding: clamp(1.4rem, 3vw, 2rem);
}

.feedback-intro p:last-child,
.feedback-form-panel p:last-child,
.field-help,
.form-note {
  color: var(--text-muted);
}

.feedback-list {
  margin: 1.1rem 0 0;
  padding-left: 1.2rem;
  color: var(--text-muted);
}

.feedback-list li + li {
  margin-top: 0.55rem;
}

.page-link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.feedback-form {
  display: grid;
  gap: 1.15rem;
}

.form-group {
  display: grid;
  gap: 0.45rem;
}

.field-label {
  font-size: 0.95rem;
  font-weight: 800;
}

.field-label .optional,
.field-label .required {
  margin-left: 0.35rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-subtle);
}

.text-input {
  width: 100%;
  min-height: 48px;
  padding: 0.82rem 0.95rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  background: var(--surface-strong);
  font: inherit;
}

textarea.text-input {
  min-height: 220px;
  resize: vertical;
}

.text-input::placeholder {
  color: var(--text-subtle);
}

.text-input:focus-visible {
  outline-offset: 1px;
}

.form-note {
  margin: 0;
  font-size: 0.9rem;
}

.manual-panel {
  display: grid;
  grid-template-columns: minmax(0, 0.75fr) minmax(420px, 1.25fr);
  gap: 2rem;
  align-items: center;
}

.manual-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.55rem;
}

.manual-links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0.48rem 0.72rem;
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text);
  background: var(--surface-strong);
  font-size: 0.9rem;
  font-weight: 800;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
}

.download-panel {
  text-align: center;
}

.download-actions {
  justify-content: center;
  margin-top: 1.4rem;
}

.site-footer {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 2rem 0 3rem;
  color: var(--text-subtle);
  text-align: center;
}

.site-footer p {
  margin: 0;
}

:focus-visible {
  outline: 3px solid var(--accent-strong);
  outline-offset: 3px;
}

:root[data-theme="high-contrast"] body {
  background: #000000;
}

:root[data-theme="high-contrast"] body::before,
:root[data-theme="high-contrast"] .glass-panel::before {
  display: none;
}

:root[data-theme="high-contrast"] .site-header,
:root[data-theme="high-contrast"] .glass-panel,
:root[data-theme="high-contrast"] .button,
:root[data-theme="high-contrast"] .manual-links a,
:root[data-theme="high-contrast"] .theme-select {
  border-width: 2px;
  box-shadow: none;
}

/* 동영상 섹션 확장 스타일 */
.video-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 1rem;
  max-width: none; /* 상단 한정 너비 해제 */
}

.youtube-shortcut {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.35rem; /* 제목 높이에 맞춤 */
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface-strong);
  color: var(--text);
  font-weight: 800;
  font-size: 0.9rem;
  text-decoration: none;
  transition: transform 0.2s, background 0.2s;
}

.youtube-shortcut:hover {
  background: var(--accent-soft);
  transform: translateY(-2px);
}

.youtube-icon {
  font-size: 1.2rem;
}

.video-playlist-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.playlist-item {
  display: flex;
  flex-direction: column;
  padding: 0.75rem;
  text-decoration: none;
  color: inherit;
  transition: transform 0.3s;
}

.playlist-item:hover {
  transform: translateY(-6px);
}

.playlist-thumb {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: calc(var(--radius-sm) - 4px);
  background: var(--bg-2); /* 단순한 배경색으로 변경 */
  margin-bottom: 1rem;
  overflow: hidden;
}

.playlist-thumb::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: rgba(0, 0, 0, 0.05);
  pointer-events: none;
}

.playlist-thumb img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.playlist-item:hover .playlist-thumb img {
  transform: scale(1.1);
}

.playlist-info h4 {
  margin: 0 0 0.4rem;
  font-size: 1.1rem;
  font-weight: 850;
}

.playlist-info p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

@media (max-width: 920px) {
  .site-header {
    grid-template-columns: 1fr;
    justify-items: stretch;
    border-radius: 26px;
  }

  .top-nav,
  .theme-switcher {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .hero,
  .manual-panel,
  .feedback-layout {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 3rem;
  }

  .guide-grid,
  .showcase-grid {
    grid-template-columns: 1fr;
  }

  .screenshot-card img {
    height: auto;
    object-fit: contain;
  }
}

@media (max-width: 560px) {
  .section-shell,
  .site-header,
  .site-footer {
    width: min(100% - 24px, 1120px);
  }

  .top-nav {
    gap: 0.75rem;
  }

  .top-nav a {
    font-size: 0.88rem;
  }

  h1 {
    font-size: 1.9rem;
  }

  .button {
    width: 100%;
  }

  .hero-actions,
  .download-actions {
    align-items: stretch;
  }

  .manual-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}