* {
  box-sizing: border-box;
}



/* Header 스타일 */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  margin-bottom: 74px;
}

.page-title {
  text-align: center;
  flex: 1;
}

.page-title h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: bold;
  color: #111;
}

/* 홈 버튼 */
.home-btn {
  -webkit-appearance: none;
  appearance: none;
  margin: 0;
  padding: 0;
  border: 0;
  outline: none;
  width: 50px;
  height: 50px;
  border-radius: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #fbfbfb;
  color: #555;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow:
  3px 3px 6px rgba(0, 0, 0, 0.08), -3px -3px 6px rgba(255, 255, 255, 0.70);
}

.home-btn img {
  width: 25px;
}



.home-btn:active {
  transform: translateY(1px);
  box-shadow:
    inset 4px 4px 8px rgba(163, 177, 198, 0.3),
    inset -4px -4px 8px rgba(255, 255, 255, 0.7);
}

/* 모드 토글 */
.mode-toggle {
  position: fixed;
  top: 22px;
  right: 20px;
  width: 70px;
  height: 37px;
  border-radius: 25px;
  background: #f9f9f9;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 3px;
  cursor: pointer;
  transition: all 0.3s ease;
  z-index: 1000;
  box-shadow:
    inset 4px 4px 8px rgba(163, 177, 198, 0.2),
    inset -4px -4px 8px rgba(255, 255, 255, 0.6);
}

.toggle-indicator {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 31px;
  height: 31px;
  border-radius: 50%;
  background: #fff;
  box-shadow:
    4px 4px 8px rgba(163, 177, 198, 0.3),
    -4px -4px 8px rgba(255, 255, 255, 0.8);
  transition: all 0.3s ease;
  z-index: 0;
}

.toggle-option {
  flex: 1;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 1;
}

.toggle-option img {
  width: 16px;
  height: 16px;
}

/* Usage 컨테이너 */
.usage-container {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
}

/* 중앙 설명 텍스트 */
.start-section {
  text-align: center;
  margin: 0 auto;
  max-width: 700px;
  padding: 18px 20px;
}

.start-title {
  font-size: 2.1rem;
  font-weight: 750;
  letter-spacing: 0.02em;
  color: #000;
  opacity: 0;
  transform: translateY(14px);
  animation: fadeSlideUpTitle 0.9s ease-out forwards;
}

.start-subtext {
  font-size: 1.2rem;
  color: #1a1a1a;
  line-height: 2.3;
  font-weight: 550;
  letter-spacing: 0.1em;
  opacity: 0;
  white-space: pre-line;
  margin-bottom: 65px;
  transform: translateY(10px);
  animation: fadeSlideUp 0.8s ease-out forwards;
  animation-delay: 0.3s;
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.1), 0 2px 4px rgb(75 75 75 / 6%);
}

@keyframes fadeSlideUpTitle {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}


@keyframes fadeSlideUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* 기능 카드들 */
.feature-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 40px;
  margin-bottom: 80px;
}

.feature-card {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  background: #fff;
  padding: 28px 24px;
  border-radius: 14px;
  border: 1px solid rgba(0,0,0,0.06);
  box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.2s ease;
}




.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: #f3f4f6;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.6);
}

.feature-icon img {
  width: 26px;
  height: 26px;
}

.feature-content h3 {
  margin: 0 0 14px 0;
  font-size: 1.2rem;
  font-weight: 600;
  color: #111;
}

.feature-content p {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.5;
  color: #333;
  margin-bottom: 15px;
}

.feature-content img {
  width: 20px;
  vertical-align: middle;
  position: relative;
  bottom: 1px;
}

.feature-content p:last-child {
  margin-bottom: 0;
}

/* 활용 팁 섹션 */
.tips-section {
  margin-bottom: 60px;
}

.tips-title {
  text-align: center;
  font-size: 1.8rem;
  font-weight: 600;
  color: #222;
  margin-bottom: 16px;
  margin-top: 0px;
}

.tips-subtitle {
  text-align: center;
  font-size: 0.95rem;
  color: #666;
  margin-bottom: 50px;
  line-height: 1.5;
}

.tips-grid {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.tip-mac-window {
  background: #fff;
  color: #111;
  border-radius: 14px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
  max-width: 768px;
  margin: 0 auto;
  border: 1px solid #e5e5e5;
  overflow: hidden;
  transition: all 0.3s ease;
}

.tip-mac-header {
  display: flex;
  align-items: center;
  height: 38px;
  background: #f1f1f1;
  padding: 0 14px;
  gap: 8px;
}

.tip-mac-header .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.tip-mac-header .red { background: #1A1A1D; }
.tip-mac-header .yellow { background: #4F4F58; }
.tip-mac-header .green { background: #6D6D7A; }

.tip-mac-body {
  padding: 32px 40px;
  background: #fff;
}

.tip-item {
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 10px;
  padding: 16px 20px;
  margin-bottom: 14px;
  background: transparent;
  transition: all 0.2s ease;
  box-shadow:
  1px 1px 3px rgba(0, 0, 0, 0.1),
  -1px -1px 3px rgba(255, 255, 255, 0.01);
}

.tip-item:hover {
  transform: translateY(-1px);
  box-shadow:
    0 5px 7px rgba(0, 0, 0, 0.06),
    inset 0 1px 0 rgba(255, 255, 255, 0.7);
}

.tip-step {
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  background: #f5f5f5;
  color: #444;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  text-transform: uppercase;
}


.tip-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}

.tip-number {
  width: 26px;
  height: 26px;
  border-radius: 6px;
  background: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  color: #222;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(0, 0, 0, 0.05);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.05),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  transition: all 0.2s ease;
}


.tip-title {
  font-weight: 600;
  font-size: 1rem;
  color: #111;
  white-space: nowrap;
}

.tip-desc {
  color: #444;
  font-size: 0.95rem;
  line-height: 1.5;
}

.tip-desc p {
  margin: 4px 0;
}

.tip-item p:last-child {
  margin-bottom: 0;
}



/* 푸터 */
.site-footer {
  margin-top: 60px;
  padding: 20px 0 40px 0;
  font-size: 10.5px;
  color: #afafaf;
  text-align: center;
}

.site-footer a {
  color: #afafaf;
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* 다크 모드 스타일 */
body.dark {
  background: #212121;
  color: #dfdfdf;
}

body.dark::before {
  background-image:
    repeating-linear-gradient(0deg, #3a3a3d 0px, #3a3a3d 1px, transparent 1px, transparent 40px),
    repeating-linear-gradient(90deg, #3a3a3d 0px, #3a3a3d 1px, transparent 1px, transparent 40px);
}



body.dark .home-btn {
  background: #f5f5f5;
  box-shadow:
    8px 8px 16px rgba(0, 0, 0, 0.4),
    -8px -8px 16px rgba(255, 255, 255, 0.05);
}


body.dark .home-btn img {
  color: black;
}

body.dark .mode-toggle {
  background: #3f3f3f;
  box-shadow:
    inset 2px 2px 3px rgba(0, 0, 0, 0.1),
    inset -2px -2px 3px rgba(255, 255, 255, 0.05);
}

body.dark .toggle-indicator {
  transform: translateX(33px);
  background: #2d2d30;
  box-shadow:
    1px 1px 3px rgba(0, 0, 0, 0.4),
    -1px -1px 3px rgba(255, 255, 255, 0.08);
}

/* 중앙 텍스트 */
body.dark .start-title {
  color: #f3f3f3;
}

body.dark .start-subtext {
  color: #d0d0d0;
  text-shadow: 0 1px 1px rgba(0,0,0,0.3), 0 2px 6px rgba(0,0,0,0.25);
}

/* 기능 카드 */
body.dark .feature-card {
  background: #2a2a2a;
  color: #e1e1e1;
  border: none;
  box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.35), -2px -2px 3px rgba(255, 255, 255, 0.04);
}

body.dark .feature-content h3 {
  color: #f0f0f0;
}

body.dark .feature-content p {
  color: #cccccc;
}

body.dark .feature-icon {
  background: #f5f5f5;
  box-shadow: inset 0 1px 1px rgba(255,255,255,0.04);
}

/* 팁 창 */
body.dark .tip-mac-window {
  background: #2a2a2a;
  color: #e1e1e1;
  border: none;
  box-shadow: 
    3px 3px 3px rgba(0, 0, 0, 0.35),
    -3px -3px 3px rgba(255, 255, 255, 0.04);
}

body.dark .tip-mac-body {
  background: #2a2a2a;
}

body.dark .tip-mac-header {
  background: #1e1e1e;
}

body.dark .tip-mac-header .red {
  background: #a3a3a3;
}
body.dark .tip-mac-header .yellow {
  background: #dfdfdf;
}
body.dark .tip-mac-header .green {
  background: #f3f3f3;
}

/* 팁 항목 */
body.dark .tip-item {
  border: 1px solid rgba(99, 99, 99, 0.08);
  background: #2a2a2a;
  color: #e1e1e1;
  box-shadow:
    2px 2px 6px rgba(0, 0, 0, 0.3),
    -2px -2px 6px rgba(255, 255, 255, 0.03);
}

body.dark .tip-item:hover {
  box-shadow:
    0 5px 7px rgba(0, 0, 0, 0.4),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

/* 숫자 라벨 */
body.dark .tip-number {
  background: #1f1f1f;
  color: #ddd;
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.3),
    inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

/* 제목 및 설명 */

body.dark .tips-title {
  filter: brightness(0) invert(0.85);
}

body.dark .tip-title {
  filter: brightness(0) invert(0.85);
}

body.dark .tip-desc {
  color: #d9d9d9;
}

body.dark .feature-content img {
  filter: brightness(0) invert(0.9);
}



/* 반응형 스타일 */
@media (max-width: 768px) {
  .header {
    margin-bottom: 40px;
    margin-top: 20px;
  }
  
  .page-title h1 {
    font-size: 1.5rem;
  }
  
  .usage-container {
    padding: 15px;
  }
  
  .intro-text {
    font-size: 1rem;
    margin-bottom: 60px;
    padding: 20px 24px;
  }
  
  .feature-cards {
    gap: 30px;
    margin-bottom: 60px;
  }
  
  .feature-card {
    padding: 24px 20px;
  }
  
  .tips-grid {
    gap: 25px;
  }
  
  .tip-item {
    padding: 20px;
  }
  
  .tips-section {
    margin-bottom: 50px;
  }
  
  .start-section {
    padding: 32px 24px;
  }

}