/* ==========================================================================
   DATZ 디지털 마케팅 에이전시 - 메인 스타일시트
   참고 디자인: Cheil Worldwide (cheil.com) 스타일
   미니멀, 클린, 화이트 배경, 다크 텍스트, 넉넉한 여백
   ========================================================================== */

/* ==========================================================================
   1. CSS 커스텀 속성 (디자인 토큰)
   ========================================================================== */
:root {
  /* 색상 팔레트 */
  --color-primary: #1a1a1a;
  --color-secondary: #666666;
  --color-accent: #0066ff;
  --color-accent-hover: #0052cc;
  --color-accent-light: rgba(0, 102, 255, 0.08);
  --color-bg: #ffffff;
  --color-bg-alt: #f5f5f5;
  --color-border: #e0e0e0;
  --color-border-light: #f0f0f0;
  --color-white: #ffffff;
  --color-success: #22c55e;
  --color-error: #ef4444;

  /* 타이포그래피 */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3.5rem;
  --font-size-hero: clamp(2.5rem, 5vw, 4rem);

  /* 간격 */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;
  --spacing-5xl: 8rem;

  /* 레이아웃 */
  --container-max: 1200px;
  --container-wide: 1400px;
  --container-padding: 1.5rem;
  --header-height: 72px;

  /* 트랜지션 */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* 그림자 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-card-hover: 0 8px 30px rgba(0, 0, 0, 0.12);

  /* 둥근 모서리 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
}

/* ==========================================================================
   2. 기본 타이포그래피
   ========================================================================== */
body {
  font-family: var(--font-family);
  color: var(--color-primary);
  background-color: var(--color-bg);
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-primary);
  word-break: keep-all;
}

p {
  line-height: 1.8;
  color: var(--color-secondary);
  word-break: keep-all;
}

/* ==========================================================================
   3. 공통 레이아웃
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section {
  padding: var(--spacing-4xl) 0;
}

.section--alt {
  background-color: var(--color-bg-alt);
}

.section__header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.section__label {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-md);
}

.section__title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.section__desc {
  font-size: var(--font-size-lg);
  color: var(--color-secondary);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ==========================================================================
   4. 헤더 / 내비게이션
   ========================================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: box-shadow var(--transition-base), background-color var(--transition-base);
}

.header--scrolled {
  box-shadow: 0 1px 0 var(--color-border);
  background-color: rgba(255, 255, 255, 0.98);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* 로고 */
.header__logo {
  font-size: var(--font-size-xl);
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.02em;
  flex-shrink: 0;
}

.header__logo:hover {
  color: var(--color-accent);
  transition: color var(--transition-fast);
}

/* 데스크톱 내비게이션 */
.nav {
  display: none;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.nav__link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-secondary);
  transition: color var(--transition-fast);
  padding: var(--spacing-sm) 0;
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width var(--transition-base);
}

.nav__link:hover,
.nav__link--active {
  color: var(--color-primary);
}

.nav__link:hover::after,
.nav__link--active::after {
  width: 100%;
}

/* 내비게이션 CTA 버튼 */
.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1.25rem;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-white);
  background-color: var(--color-accent);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}

.nav__cta:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-1px);
}

/* 모바일 햄버거 메뉴 버튼 */
.hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  cursor: pointer;
  z-index: 1001;
  background: none;
  border: none;
  padding: 0;
}

.hamburger__line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-primary);
  transition: transform var(--transition-base), opacity var(--transition-fast);
}

.hamburger__line:nth-child(1) {
  margin-bottom: 6px;
}

.hamburger__line:nth-child(3) {
  margin-top: 6px;
}

/* 햄버거 메뉴 활성화 상태 */
.hamburger--active .hamburger__line:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger--active .hamburger__line:nth-child(2) {
  opacity: 0;
}

.hamburger--active .hamburger__line:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* 모바일 내비게이션 오버레이 */
.mobile-nav {
  position: fixed;
  top: 0;
  right: -100%;
  width: 100%;
  max-width: 320px;
  height: 100vh;
  background-color: var(--color-bg);
  z-index: 999;
  padding: calc(var(--header-height) + var(--spacing-xl)) var(--spacing-xl) var(--spacing-xl);
  transition: right var(--transition-base);
  box-shadow: -5px 0 30px rgba(0, 0, 0, 0.1);
  overflow-y: auto;
}

.mobile-nav--open {
  right: 0;
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.mobile-nav__link {
  display: block;
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--color-secondary);
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border-light);
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.mobile-nav__link:hover,
.mobile-nav__link--active {
  color: var(--color-primary);
  padding-left: var(--spacing-sm);
}

.mobile-nav__cta {
  display: block;
  text-align: center;
  margin-top: var(--spacing-xl);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-white);
  background-color: var(--color-accent);
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.mobile-nav__cta:hover {
  background-color: var(--color-accent-hover);
}

/* 모바일 메뉴 배경 오버레이 */
.mobile-nav-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.3);
  z-index: 998;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.mobile-nav-overlay--visible {
  opacity: 1;
  visibility: visible;
}

/* ==========================================================================
   5. 히어로 섹션
   ========================================================================== */
.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: var(--header-height) var(--container-padding) var(--spacing-3xl);
  text-align: center;
  background-color: var(--color-bg);
  position: relative;
  overflow: hidden;
}

.hero__content {
  max-width: 800px;
  margin: 0 auto;
}

.hero__label {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: var(--spacing-lg);
}

.hero__title {
  font-size: var(--font-size-hero);
  font-weight: 800;
  line-height: 1.2;
  color: var(--color-primary);
  margin-bottom: var(--spacing-lg);
  letter-spacing: -0.02em;
  word-break: keep-all;
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-2xl);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  word-break: keep-all;
}

.hero__actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
}

.hero__en-tagline {
  font-size: var(--font-size-sm);
  color: var(--color-secondary);
  font-weight: 400;
  letter-spacing: 0.05em;
  margin-top: var(--spacing-xl);
  opacity: 0.7;
}

/* 히어로 배경 장식 */
.hero__decoration {
  position: absolute;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 102, 255, 0.03) 0%, transparent 70%);
  pointer-events: none;
}

.hero__decoration--1 {
  top: -100px;
  right: -150px;
}

.hero__decoration--2 {
  bottom: -200px;
  left: -200px;
}

/* ==========================================================================
   6. 버튼 스타일
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 0.875rem 2rem;
  font-size: var(--font-size-base);
  font-weight: 600;
  line-height: 1;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  cursor: pointer;
  white-space: nowrap;
  border: 2px solid transparent;
}

.btn--primary {
  color: var(--color-white);
  background-color: var(--color-accent);
  border-color: var(--color-accent);
}

.btn--primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 102, 255, 0.3);
}

.btn--outline {
  color: var(--color-primary);
  background-color: transparent;
  border-color: var(--color-border);
}

.btn--outline:hover {
  border-color: var(--color-primary);
  background-color: var(--color-bg-alt);
}

.btn--sm {
  padding: 0.625rem 1.25rem;
  font-size: var(--font-size-sm);
}

.btn--lg {
  padding: 1rem 2.5rem;
  font-size: var(--font-size-lg);
}

/* 포커스 스타일 (접근성) */
.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* ==========================================================================
   7. 서비스 섹션
   ========================================================================== */
.services {
  padding: var(--spacing-5xl) 0;
}

.services__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
}

.service-card {
  padding: var(--spacing-2xl);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.service-card:hover {
  border-color: var(--color-border);
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-4px);
}

.service-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  margin-bottom: var(--spacing-lg);
  background-color: var(--color-accent-light);
  border-radius: var(--radius-md);
  color: var(--color-accent);
}

.service-card__icon svg {
  width: 28px;
  height: 28px;
}

.service-card__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.service-card__desc {
  font-size: var(--font-size-sm);
  color: var(--color-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   8. 회사 소개 섹션
   ========================================================================== */
.about {
  padding: var(--spacing-5xl) 0;
  background-color: var(--color-bg-alt);
}

.about__content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-3xl);
}

.about__text {
  max-width: 560px;
}

.about__vision {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
}

.about__vision-item {
  padding-left: var(--spacing-lg);
  border-left: 3px solid var(--color-accent);
}

.about__vision-label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: var(--spacing-xs);
}

.about__vision-text {
  font-size: var(--font-size-base);
  color: var(--color-secondary);
  line-height: 1.7;
}

/* 핵심 가치 */
.about__values {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

.about__value-item {
  padding: var(--spacing-lg);
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  text-align: center;
}

.about__value-title {
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--color-primary);
}

/* 통계 카운터 */
.stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
}

.stat {
  text-align: center;
  padding: var(--spacing-xl);
  background-color: var(--color-bg);
  border-radius: var(--radius-lg);
}

.stat__number {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.stat__number span {
  color: var(--color-accent);
}

.stat__label {
  font-size: var(--font-size-sm);
  color: var(--color-secondary);
  font-weight: 500;
}

/* ==========================================================================
   9. 포트폴리오 섹션
   ========================================================================== */
.portfolio {
  padding: var(--spacing-5xl) 0;
}

/* 포트폴리오 필터 */
.portfolio__filters {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-2xl);
}

.portfolio__filter-btn {
  padding: 0.5rem 1.25rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-secondary);
  background-color: transparent;
  border: 1px solid var(--color-border);
  border-radius: 100px;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.portfolio__filter-btn:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.portfolio__filter-btn--active {
  color: var(--color-white);
  background-color: var(--color-primary);
  border-color: var(--color-primary);
}

.portfolio__filter-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* 포트폴리오 그리드 */
.portfolio__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
}

.portfolio-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
}

.portfolio-card:hover {
  box-shadow: var(--shadow-card-hover);
  transform: translateY(-4px);
}

.portfolio-card[hidden] {
  display: none;
}

/* 포트폴리오 카드 썸네일 */
.portfolio-card__thumb {
  position: relative;
  width: 100%;
  padding-top: 60%;
  overflow: hidden;
}

.portfolio-card__thumb-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-slow);
}

.portfolio-card:hover .portfolio-card__thumb-bg {
  transform: scale(1.05);
}

.portfolio-card__thumb-text {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-white);
  opacity: 0.9;
}

/* 포트폴리오 카드 본문 */
.portfolio-card__body {
  padding: var(--spacing-lg);
}

.portfolio-card__category {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: var(--spacing-sm);
}

.portfolio-card__title {
  font-size: var(--font-size-base);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
}

.portfolio-card__result {
  font-size: var(--font-size-sm);
  color: var(--color-secondary);
  line-height: 1.6;
}

/* ==========================================================================
   10. 문의 섹션
   ========================================================================== */
.contact {
  padding: var(--spacing-5xl) 0;
  background-color: var(--color-bg-alt);
}

.contact__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-3xl);
}

/* 문의 폼 */
.contact-form {
  background-color: var(--color-bg);
  padding: var(--spacing-2xl);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-light);
}

.contact-form__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-bottom: var(--spacing-xl);
  color: var(--color-primary);
}

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-group__label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.form-group__label .required {
  color: var(--color-error);
  margin-left: 2px;
}

.form-group__input,
.form-group__select,
.form-group__textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: var(--font-size-base);
  color: var(--color-primary);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group__input:focus,
.form-group__select:focus,
.form-group__textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.form-group__input::placeholder,
.form-group__textarea::placeholder {
  color: #aaa;
}

.form-group__select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
  cursor: pointer;
}

.form-group__textarea {
  min-height: 140px;
  resize: vertical;
}

/* 폼 에러 메시지 */
.form-group__error {
  font-size: var(--font-size-xs);
  color: var(--color-error);
  margin-top: var(--spacing-xs);
  display: none;
}

.form-group--error .form-group__input,
.form-group--error .form-group__select,
.form-group--error .form-group__textarea {
  border-color: var(--color-error);
}

.form-group--error .form-group__error {
  display: block;
}

/* 폼 제출 버튼 */
.contact-form__submit {
  width: 100%;
  margin-top: var(--spacing-md);
}

/* 성공 메시지 */
.contact-form__success {
  display: none;
  text-align: center;
  padding: var(--spacing-2xl);
}

.contact-form__success--visible {
  display: block;
}

.contact-form__success-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--spacing-lg);
  background-color: rgba(34, 197, 94, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-success);
}

.contact-form__success-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.contact-form__success-desc {
  font-size: var(--font-size-base);
  color: var(--color-secondary);
}

/* 연락처 정보 */
.contact-info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.contact-info__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.contact-info__desc {
  font-size: var(--font-size-base);
  color: var(--color-secondary);
  line-height: 1.7;
}

.contact-info__items {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.contact-info__item {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-md);
}

.contact-info__item-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-accent-light);
  border-radius: var(--radius-md);
  color: var(--color-accent);
}

.contact-info__item-icon svg {
  width: 20px;
  height: 20px;
}

.contact-info__item-label {
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 2px;
}

.contact-info__item-value {
  font-size: var(--font-size-base);
  color: var(--color-primary);
  font-weight: 500;
}

.contact-info__item-value a {
  color: var(--color-primary);
  transition: color var(--transition-fast);
}

.contact-info__item-value a:hover {
  color: var(--color-accent);
}

/* ==========================================================================
   11. 푸터
   ========================================================================== */
.footer {
  background-color: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer__brand {
  max-width: 320px;
}

.footer__logo {
  font-size: var(--font-size-xl);
  font-weight: 800;
  margin-bottom: var(--spacing-md);
  color: var(--color-white);
}

.footer__desc {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
}

.footer__links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-xl);
}

.footer__links-title {
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--spacing-md);
}

.footer__links-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer__link {
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-white);
}

/* 소셜 미디어 링크 */
.footer__social {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.7);
  transition: all var(--transition-fast);
}

.footer__social-link:hover {
  background-color: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
}

.footer__social-link svg {
  width: 18px;
  height: 18px;
}

/* 푸터 하단 */
.footer__bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-md);
  padding-top: var(--spacing-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__copyright {
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.4);
}

.footer__legal {
  display: flex;
  gap: var(--spacing-lg);
}

.footer__legal-link {
  font-size: var(--font-size-xs);
  color: rgba(255, 255, 255, 0.4);
  transition: color var(--transition-fast);
}

.footer__legal-link:hover {
  color: rgba(255, 255, 255, 0.8);
}

/* ==========================================================================
   12. 맨 위로 가기 버튼
   ========================================================================== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-primary);
  color: var(--color-white);
  border-radius: 50%;
  cursor: pointer;
  z-index: 900;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-lg);
  border: none;
}

.back-to-top--visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background-color: var(--color-accent);
  transform: translateY(-2px);
}

.back-to-top:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* ==========================================================================
   13. 스크롤 애니메이션
   ========================================================================== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

.reveal--delay-1 { transition-delay: 0.1s; }
.reveal--delay-2 { transition-delay: 0.2s; }
.reveal--delay-3 { transition-delay: 0.3s; }
.reveal--delay-4 { transition-delay: 0.4s; }
.reveal--delay-5 { transition-delay: 0.5s; }
.reveal--delay-6 { transition-delay: 0.6s; }

/* ==========================================================================
   14. 반응형 미디어 쿼리
   ========================================================================== */

/* 태블릿 (768px 이상) */
@media (min-width: 768px) {
  :root {
    --container-padding: 2rem;
    --spacing-4xl: 5rem;
    --spacing-5xl: 7rem;
  }

  .section__title {
    font-size: var(--font-size-4xl);
  }

  /* 히어로 */
  .hero__actions {
    flex-direction: row;
    justify-content: center;
  }

  /* 서비스 그리드: 2열 */
  .services__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
  }

  /* 회사 소개 */
  .stats {
    grid-template-columns: repeat(4, 1fr);
  }

  /* 포트폴리오 그리드: 2열 */
  .portfolio__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
  }

  /* 문의 폼 레이아웃 */
  .contact__inner {
    grid-template-columns: 1fr 1fr;
  }

  .contact-form__row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
  }

  /* 푸터 */
  .footer__inner {
    grid-template-columns: 1fr 1fr;
  }

  .footer__bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}

/* 데스크톱 (1024px 이상) */
@media (min-width: 1024px) {
  :root {
    --container-padding: 2.5rem;
  }

  /* 내비게이션: 데스크톱 표시 */
  .nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
  }

  .hamburger {
    display: none;
  }

  .mobile-nav,
  .mobile-nav-overlay {
    display: none;
  }

  /* 서비스 그리드: 3열 */
  .services__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  /* 회사 소개: 2열 레이아웃 */
  .about__content {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }

  /* 포트폴리오 그리드: 3열 */
  .portfolio__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  /* 푸터 */
  .footer__inner {
    grid-template-columns: 1.5fr 1fr 1fr;
  }

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

/* 와이드 데스크톱 (1440px 이상) */
@media (min-width: 1440px) {
  :root {
    --container-max: 1320px;
  }

  .service-card {
    padding: var(--spacing-2xl) var(--spacing-2xl);
  }
}

/* ==========================================================================
   15. 접근성 포커스 스타일
   ========================================================================== */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* 키보드 네비게이션 시에만 포커스 표시 */
:focus:not(:focus-visible) {
  outline: none;
}

/* ==========================================================================
   16. 인쇄 스타일
   ========================================================================== */
@media print {
  .header,
  .hamburger,
  .mobile-nav,
  .mobile-nav-overlay,
  .back-to-top,
  .hero__decoration {
    display: none !important;
  }

  .hero {
    min-height: auto;
    padding: var(--spacing-xl) 0;
  }

  .section {
    padding: var(--spacing-xl) 0;
  }

  body {
    font-size: 12pt;
    color: #000;
  }
}