/* ============================================
   손재이 Backend Portfolio
   디자인: 다크 모노톤 + 미세한 그린 액센트
   ============================================ */

:root {
  --bg: #0e1014;
  --bg-2: #14171d;
  --bg-3: #1a1e25;
  --line: #262b34;
  --line-2: #1f242c;
  --text: #e8eaed;
  --text-2: #a8aeb8;
  --text-3: #6b7280;
  --accent: #4ade80;       /* moi 이미지의 그린 톤 */
  --accent-soft: rgba(74, 222, 128, 0.12);
  --serif: "Fraunces", "Pretendard Variable", serif;
  --sans: "Pretendard Variable", -apple-system, BlinkMacSystemFont, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-feature-settings: "ss02", "ss03";
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ============================================
   NAV
   ============================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 56px;
  background: rgba(14, 16, 20, 0.78);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line-2);
}

.nav-logo {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 500;
  letter-spacing: -0.02em;
}
.nav-logo .dot { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
}
.nav-links a {
  font-size: 13px;
  color: var(--text-2);
  letter-spacing: 0.02em;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

/* ============================================
   HERO
   ============================================ */
.hero {
  min-height: 100vh;
  padding: 160px 56px 80px;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 30%;
  right: -10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-soft) 0%, transparent 70%);
  pointer-events: none;
}

.hero-grid {
  max-width: 1320px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 80px;
  align-items: center;
  position: relative;
  z-index: 1;
}

.eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 28px;
}

.hero-title {
  font-family: var(--serif);
  font-size: clamp(40px, 5vw, 68px);
  line-height: 1.15;
  font-weight: 400;
  letter-spacing: -0.025em;
  margin-bottom: 32px;
}
.hero-title em {
  font-style: italic;
  font-weight: 300;
  color: var(--accent);
}

.hero-sub {
  font-size: 16px;
  color: var(--text-2);
  line-height: 1.8;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 14px 26px;
  font-size: 14px;
  font-weight: 500;
  border-radius: 999px;
  transition: all 0.25s;
  border: 1px solid transparent;
}
.btn-primary {
  background: var(--accent);
  color: #0a0d12;
}
.btn-primary:hover {
  background: #6aef9a;
  transform: translateY(-1px);
}
.btn-ghost {
  border-color: var(--line);
  color: var(--text-2);
}
.btn-ghost:hover {
  border-color: var(--text-2);
  color: var(--text);
}

.hero-card {
  background: linear-gradient(180deg, var(--bg-2), var(--bg-3));
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 32px;
}
.hero-card-row {
  display: flex;
  justify-content: space-between;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-2);
  font-size: 14px;
}
.hero-card-row:last-child { border-bottom: none; }
.hero-card-label {
  color: var(--text-3);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.hero-card-value {
  color: var(--text);
  text-align: right;
}
.status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  margin-right: 6px;
  box-shadow: 0 0 0 4px rgba(74, 222, 128, 0.2);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(74, 222, 128, 0.2); }
  50% { box-shadow: 0 0 0 8px rgba(74, 222, 128, 0); }
}

/* ============================================
   SECTION COMMON
   ============================================ */
.section {
  max-width: 1320px;
  margin: 0 auto;
  padding: 120px 56px;
}

.section-eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 18px;
}

.section-title {
  font-family: var(--serif);
  font-size: clamp(32px, 4vw, 48px);
  line-height: 1.2;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

.section-desc {
  color: var(--text-2);
  font-size: 16px;
  max-width: 720px;
  margin-bottom: 64px;
}

/* ============================================
   ABOUT
   ============================================ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 72px;
  margin-top: 48px;
  margin-bottom: 80px;
}
.about-lead {
  font-family: var(--serif);
  font-size: 22px;
  line-height: 1.55;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--text);
}
.about-body p {
  color: var(--text-2);
  margin-bottom: 18px;
  line-height: 1.85;
}
.about-body strong {
  color: var(--text);
  font-weight: 500;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding-top: 48px;
  border-top: 1px solid var(--line);
}
.stat {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.stat-num {
  font-family: var(--serif);
  font-size: 56px;
  font-weight: 400;
  letter-spacing: -0.04em;
  line-height: 1;
}
.stat-unit {
  font-size: 22px;
  color: var(--text-2);
  margin-left: 4px;
}
.stat-label {
  font-size: 13px;
  color: var(--text-3);
}

/* ============================================
   STACK
   ============================================ */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 56px;
}
.stack-card {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 32px;
  transition: border-color 0.2s;
}
.stack-card:hover { border-color: var(--text-3); }

.stack-card-title {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 22px;
  color: var(--text);
}
.stack-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.stack-list li {
  display: flex;
  gap: 14px;
  align-items: baseline;
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.55;
}
.stack-key {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 3px 8px;
  border: 1px solid var(--accent-soft);
  border-radius: 4px;
  flex-shrink: 0;
  min-width: 56px;
  text-align: center;
}

/* ============================================
   PROJECTS
   ============================================ */
.project {
  margin-bottom: 100px;
  padding-bottom: 80px;
  border-bottom: 1px solid var(--line-2);
}
.project:last-of-type { border-bottom: none; }

.project-meta {
  display: flex;
  gap: 10px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}
.project-tag {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-2);
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
}
.project-tag.tag-progress {
  background: var(--accent-soft);
  border-color: transparent;
  color: var(--accent);
}

.project-grid {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
  gap: 64px;
  align-items: start;
}
.project-grid-reverse {
  direction: rtl;
}
.project-grid-reverse > * { direction: ltr; }

.project-title {
  font-family: var(--serif);
  font-size: 44px;
  font-weight: 400;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: 20px;
}
.project-sub {
  font-size: 22px;
  color: var(--text-3);
  font-style: italic;
  font-weight: 300;
}

.project-desc {
  font-size: 16px;
  color: var(--text-2);
  line-height: 1.85;
  margin-bottom: 32px;
}
.project-desc strong {
  color: var(--text);
  font-weight: 500;
}
.project-desc em {
  font-style: italic;
  color: var(--text);
}

.project-h4 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 32px 0 14px;
}

.project-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.project-list li {
  font-size: 14.5px;
  color: var(--text-2);
  line-height: 1.7;
  padding-left: 18px;
  position: relative;
}
.project-list li::before {
  content: "";
  position: absolute;
  left: 0; top: 11px;
  width: 6px; height: 1px;
  background: var(--text-3);
}
.project-list strong {
  color: var(--text);
  font-weight: 500;
}
.project-list code {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 1px 6px;
  border-radius: 4px;
}

.project-visual {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
  overflow: hidden;
  position: sticky;
  top: 100px;
}
.project-visual img {
  border-radius: 8px;
  width: 100%;
  height: auto;
}

.project-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 40px;
}
.project-stack span {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-2);
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 6px 12px;
  border-radius: 6px;
}

/* 이전 프로젝트 */
.subsection-title {
  font-family: var(--serif);
  font-size: 28px;
  font-weight: 400;
  letter-spacing: -0.02em;
  margin-top: 32px;
  margin-bottom: 32px;
  color: var(--text);
}

.prev-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.prev-card {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 32px;
}
.prev-title {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}
.prev-desc {
  font-size: 14.5px;
  color: var(--text-2);
  line-height: 1.75;
  margin-bottom: 16px;
}
.prev-highlight {
  font-size: 14px;
  color: var(--text-2);
  line-height: 1.7;
  padding: 14px 16px;
  background: var(--bg-3);
  border-left: 2px solid var(--accent);
  border-radius: 4px;
  margin-bottom: 20px;
}
.prev-highlight strong { color: var(--text); }
.prev-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.prev-stack span {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-2);
  background: var(--bg-3);
  padding: 4px 10px;
  border-radius: 4px;
}

/* ============================================
   EXPERIENCE
   ============================================ */
.timeline {
  margin-top: 56px;
  position: relative;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 180px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}

.tl-item {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 56px;
  padding: 24px 0;
  position: relative;
}
.tl-item::before {
  content: "";
  position: absolute;
  left: 176px;
  top: 32px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 2px solid var(--accent);
  border-radius: 50%;
}

.tl-date {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-3);
  letter-spacing: 0.03em;
  padding-top: 4px;
}

.tl-title {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
}
.tl-sub {
  font-size: 14px;
  color: var(--text-3);
  font-weight: 400;
  font-style: italic;
  margin-left: 6px;
}
.tl-body p {
  color: var(--text-2);
  font-size: 14.5px;
  line-height: 1.8;
}
.tl-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 14px;
}
.tl-stack span {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--text-2);
  background: var(--bg-2);
  border: 1px solid var(--line);
  padding: 4px 10px;
  border-radius: 4px;
}

.cert-row {
  margin-top: 64px;
  padding-top: 56px;
  border-top: 1px solid var(--line);
}
.cert-title {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  margin-bottom: 20px;
}
.cert-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.cert-list li {
  font-size: 14.5px;
  color: var(--text-2);
}
.cert-year {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text-3);
  margin-right: 18px;
}

/* ============================================
   CONTACT
   ============================================ */
.section-contact {
  text-align: center;
  padding-bottom: 80px;
}
.section-contact .section-eyebrow,
.section-contact .section-title {
  text-align: center;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 56px;
}
.contact-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 36px 24px;
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-radius: 16px;
  text-align: left;
  transition: all 0.25s;
}
a.contact-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.contact-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}
.contact-value {
  font-size: 16px;
  color: var(--text);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  border-top: 1px solid var(--line);
  padding: 36px 56px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-3);
}
.footer-sub {
  font-family: var(--mono);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 900px) {
  .nav { padding: 16px 24px; }
  .nav-links { gap: 20px; }
  .nav-links a { font-size: 12px; }

  .hero { padding: 130px 24px 60px; }
  .hero-grid { grid-template-columns: 1fr; gap: 48px; }

  .section { padding: 80px 24px; }

  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .stat-row { grid-template-columns: repeat(2, 1fr); }

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

  .project-grid,
  .project-grid-reverse {
    grid-template-columns: 1fr;
    gap: 40px;
    direction: ltr;
  }
  .project-visual { position: static; }
  .project-title { font-size: 36px; }

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

  .timeline::before { left: 6px; }
  .tl-item {
    grid-template-columns: 1fr;
    gap: 8px;
    padding-left: 28px;
  }
  .tl-item::before { left: 2px; top: 30px; }

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

  .footer { padding: 24px; flex-direction: column; gap: 8px; }
}

/* ============================================
   ANIMATIONS
   ============================================ */
@media (prefers-reduced-motion: no-preference) {
  .hero-left > * {
    opacity: 0;
    animation: fadeUp 0.8s ease-out forwards;
  }
  .hero-left > *:nth-child(1) { animation-delay: 0.1s; }
  .hero-left > *:nth-child(2) { animation-delay: 0.2s; }
  .hero-left > *:nth-child(3) { animation-delay: 0.3s; }
  .hero-left > *:nth-child(4) { animation-delay: 0.4s; }

  .hero-card {
    opacity: 0;
    animation: fadeUp 0.8s ease-out 0.5s forwards;
  }
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}