/* ============================================================
   D_FFERENT Company Website — styles.css
   Version: v1.0 | 2026-02-27
   LOCK-006: 외부 폰트·CDN·스크립트 일절 없음
   ============================================================ */

/* ── 1. CSS Variables ───────────────────────────────────────── */
:root {
  /* Colors */
  --color-bg:        #FFFFFF;
  --color-text:      #111111;
  --color-muted:     #555555;
  --color-border:    #E6E6E6;
  --color-surface:   #FAFAFA;
  --color-cta-bg:    #111111;
  --color-cta-text:  #FFFFFF;

  /* Layout */
  --max-width:       1080px;
  --pad-mobile:      20px;
  --pad-desktop:     32px;
  --section-v-mobile: 56px;
  --section-v-desktop: 80px;
  --card-gap-mobile: 16px;
  --card-gap-desktop: 20px;

  /* Typography */
  --font-stack: system-ui, -apple-system, "Segoe UI", Roboto,
                "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
  --font-base:    16px;
  --lh-base:      1.7;
  --lh-heading:   1.25;

  /* Motion */
  --transition-fast: 120ms ease;
}

/* ── 2. Reset & Base ────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--font-base);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-stack);
  font-size: 1rem;
  line-height: var(--lh-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul, ol {
  list-style: none;
}

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

a:hover {
  text-decoration: underline;
}

/* Focus ring — LOCK: outline 제거 금지 */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-text);
  outline-offset: 3px;
  border-radius: 2px;
  text-decoration: none;
}

/* ── 3. Layout Container ────────────────────────────────────── */
.container {
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--pad-mobile);
  padding-right: var(--pad-mobile);
}

/* ── 4. Site Header ─────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  gap: 12px;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: 0;
  flex-shrink: 0;
  text-decoration: none;
}

.site-logo:hover {
  text-decoration: none;
  opacity: 0.8;
}

.site-logo img {
  height: 22px;
  width: auto;
  display: block;
}

.logo-text {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
  line-height: 1;
}

/* Navigation */
.site-nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-muted);
  text-decoration: none;
  padding-bottom: 2px;
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--color-text);
  text-decoration: none;
}

.nav-links a.active {
  color: var(--color-text);
  font-weight: 700;
  border-bottom: 2px solid var(--color-text);
  padding-bottom: 0;
}

/* Header CTA — 모바일에서 숨김 */
.nav-cta {
  display: none;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-cta-text);
  background-color: var(--color-cta-bg);
  padding: 7px 14px;
  border-radius: 4px;
  text-decoration: none;
  white-space: nowrap;
  transition: opacity var(--transition-fast);
  flex-shrink: 0;
}

.nav-cta:hover {
  text-decoration: none;
  opacity: 0.8;
}

/* ── 5. Main ─────────────────────────────────────────────────── */
main {
  min-height: 50vh;
}

/* ── 6. Section (공통) ──────────────────────────────────────── */
.section {
  padding-top: var(--section-v-mobile);
  padding-bottom: var(--section-v-mobile);
}

.section + .section {
  border-top: 1px solid var(--color-border);
}

/* Section Header */
.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.section-title {
  font-size: 1.375rem;
  font-weight: 700;
  line-height: var(--lh-heading);
  color: var(--color-text);
  margin-bottom: 6px;
}

.section-desc {
  font-size: 0.875rem;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 28px;
}

/* ── 7. Hero ─────────────────────────────────────────────────── */
.hero {
  padding-top: 56px;
  padding-bottom: 56px;
}

.hero-tagline {
  font-size: 1.625rem;
  font-weight: 700;
  line-height: var(--lh-heading);
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: 16px;
  word-break: keep-all;
}

.hero-subcopy {
  font-size: 0.9rem;
  color: var(--color-text);
  line-height: 1.75;
}

.hero-subcopy p + p {
  margin-top: 2px;
}

.hero-en {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--color-border);
}

.hero-en p {
  font-size: 0.825rem;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 2px;
}

/* ── 8. Service Cards (What We Do) ──────────────────────────── */
.cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--card-gap-mobile);
  margin-top: 28px;
}

.card {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 22px 24px;
}

.card-title {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
  line-height: 1.4;
}

.card-desc {
  font-size: 0.86rem;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 14px;
}

.card-deliverables {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.card-deliverables li {
  font-size: 0.8rem;
  color: var(--color-muted);
  padding-left: 14px;
  position: relative;
  line-height: 1.5;
}

.card-deliverables li::before {
  content: "·";
  position: absolute;
  left: 0;
  font-weight: 700;
  color: var(--color-border);
}

/* ── 9. Works (Featured Projects) ──────────────────────────── */
.works-note {
  font-size: 0.8rem;
  color: var(--color-muted);
  line-height: 1.6;
  margin-top: 8px;
  margin-bottom: 28px;
  padding-left: 0;
}

.works-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--card-gap-mobile);
}

.work-card {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 22px 24px;
}

.work-card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.work-year {
  font-size: 0.75rem;
  color: var(--color-muted);
}

.work-category {
  font-size: 0.75rem;
  color: var(--color-muted);
  border: 1px solid var(--color-border);
  padding: 2px 8px;
  border-radius: 2px;
  letter-spacing: 0.02em;
}

.work-client {
  font-size: 0.75rem;
  color: var(--color-muted);
}

.work-card-title {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.45;
  margin-bottom: 8px;
}

.work-card-summary {
  font-size: 0.85rem;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 12px;
}

.work-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 12px;
}

.work-tag {
  font-size: 0.72rem;
  color: var(--color-muted);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  padding: 1px 7px;
  border-radius: 2px;
}

.work-confidential {
  font-size: 0.76rem;
  color: var(--color-muted);
  opacity: 0.75;
  padding-top: 10px;
  border-top: 1px solid var(--color-border);
  margin-top: 4px;
}

/* ── 10. How We Work ────────────────────────────────────────── */
.how-list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.how-list li {
  font-size: 0.9rem;
  color: var(--color-text);
  line-height: 1.7;
  padding-left: 20px;
  position: relative;
}

.how-list li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--color-muted);
  font-weight: 400;
}

/* ── 11. CTA Section ────────────────────────────────────────── */
.section-cta {
  background-color: var(--color-surface);
  text-align: center;
  border-top: 1px solid var(--color-border) !important;
}

.cta-title {
  font-size: 1.2rem;
  font-weight: 700;
  line-height: var(--lh-heading);
  margin-bottom: 10px;
}

.cta-sub {
  font-size: 0.875rem;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 24px;
}

.btn-cta {
  display: inline-block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-cta-text);
  background-color: var(--color-cta-bg);
  padding: 14px 32px;
  border-radius: 4px;
  text-decoration: none;
  transition: opacity var(--transition-fast);
}

.btn-cta:hover {
  text-decoration: none;
  opacity: 0.8;
}

.cta-footnote {
  font-size: 0.76rem;
  color: var(--color-muted);
  margin-top: 14px;
  opacity: 0.85;
}

/* ── 12. About: Intro ───────────────────────────────────────── */
.about-intro-body {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.85;
  margin-bottom: 4px;
  word-break: keep-all;
}

.about-en {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--color-border);
}

.about-en p {
  font-size: 0.825rem;
  color: var(--color-muted);
  line-height: 1.75;
  margin-bottom: 2px;
}

/* ── 13. About: Values (Mission) ────────────────────────────── */
.values-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--card-gap-mobile);
  margin-top: 28px;
}

.value-card {
  border-left: 3px solid var(--color-text);
  padding: 18px 20px 18px 22px;
  background-color: var(--color-surface);
  border-radius: 0 6px 6px 0;
}

.value-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
  line-height: 1.4;
}

.value-desc {
  font-size: 0.85rem;
  color: var(--color-muted);
  line-height: 1.65;
}

/* ── 14. About: Collaboration ──────────────────────────────── */
/* reuses .how-list */

/* ── 15. About: Verification Box ──────────────────────────── */
.verify-box {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 20px 22px;
  background-color: var(--color-surface);
  margin-top: 24px;
}

.verify-box p {
  font-size: 0.83rem;
  color: var(--color-muted);
  line-height: 1.7;
}

.verify-box p + p {
  margin-top: 4px;
}

/* ── 16. Site Footer ────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-top: 32px;
  padding-bottom: 36px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-brand {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--color-text);
}

.footer-desc {
  font-size: 0.78rem;
  color: var(--color-muted);
  line-height: 1.6;
}

.footer-contact {
  font-size: 0.78rem;
  color: var(--color-muted);
  margin-top: 4px;
}

.footer-contact a {
  color: var(--color-muted);
  text-decoration: none;
}

.footer-contact a:hover {
  color: var(--color-text);
  text-decoration: underline;
}

/* ============================================================
   Responsive Breakpoints
   ============================================================ */

/* ── >= 640px: Header CTA 노출 ──────────────────────────────── */
@media (min-width: 640px) {
  .nav-cta {
    display: inline-block;
  }
}

/* ── >= 768px: 2열 레이아웃, 데스크탑 여백 ─────────────────── */
@media (min-width: 768px) {

  .container {
    padding-left: var(--pad-desktop);
    padding-right: var(--pad-desktop);
  }

  .section {
    padding-top: var(--section-v-desktop);
    padding-bottom: var(--section-v-desktop);
  }

  .hero {
    padding-top: 80px;
    padding-bottom: 80px;
  }

  .hero-tagline {
    font-size: 2.0rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--card-gap-desktop);
  }

  .works-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--card-gap-desktop);
  }

  .values-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--card-gap-desktop);
  }

  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
    gap: 24px;
  }

  .footer-contact {
    margin-top: 0;
    text-align: right;
    flex-shrink: 0;
  }
}

/* ── >= 1024px: Wide 3열, 여백 확대 ────────────────────────── */
@media (min-width: 1024px) {

  .hero-tagline {
    font-size: 2.125rem;
  }

  .cards-grid {
    /* 서비스 카드는 2열 유지 (4개 → 2×2) */
    grid-template-columns: repeat(2, 1fr);
  }

  .works-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}