/* ────────────────────────────────────────────────
   남상도 Portfolio · style.css
   Design — clean, technical, dev-first
───────────────────────────────────────────────── */

:root {
  --c-bg: #ffffff;
  --c-bg-alt: #f8fafc;
  --c-bg-cta: #0f172a;
  --c-fg: #0f172a;
  --c-muted: #475569;
  --c-line: #e2e8f0;
  --c-line-2: #cbd5e1;
  --c-accent: #2563eb;
  --c-accent-2: #1d4ed8;
  --c-tag-bg: #eff6ff;
  --c-tag-fg: #1d4ed8;
  --c-success: #16a34a;
  --c-warn: #d97706;
  --radius: 12px;
  --radius-sm: 6px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 6px 24px -8px rgba(15, 23, 42, 0.18);
  --container: 1140px;
  --space-section: clamp(60px, 8vw, 100px);
  --font-sans: "Inter", "Noto Sans KR", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Consolas", monospace;
}

/* ─── Reset ─────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--c-fg);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; display: block; }
ul { padding: 0; margin: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
a:hover { color: var(--c-accent); }
code, pre { font-family: var(--font-mono); }
:focus-visible { outline: 2px solid var(--c-accent); outline-offset: 2px; }

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.only-desktop { display: none; }
@media (min-width: 768px) { .only-desktop { display: inline; } }

/* ─── Buttons ───────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 18px;
  font-size: 0.92rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
  white-space: nowrap;
}
.btn--primary {
  background: var(--c-accent);
  color: #fff;
}
.btn--primary:hover { background: var(--c-accent-2); color: #fff; transform: translateY(-1px); }
.btn--ghost {
  background: transparent;
  color: var(--c-fg);
  border-color: var(--c-line-2);
}
.btn--ghost:hover { background: var(--c-tag-bg); color: var(--c-accent); border-color: var(--c-accent); }
.btn--sm { padding: 7px 12px; font-size: 0.82rem; }

/* ─── Nav ───────────────────────────────────────── */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--c-line);
}
.nav__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.nav__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1rem;
}
.nav__brand-logo {
  width: 30px; height: 30px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--c-accent), #6366f1);
  color: #fff;
  font-weight: 800;
  letter-spacing: -0.5px;
}
.nav__brand-en {
  font-weight: 500;
  color: var(--c-muted);
  font-size: 0.85em;
}
.nav__links {
  display: none;
  margin-left: auto;
  gap: 22px;
  font-size: 0.92rem;
  font-weight: 500;
}
.nav__links a { color: var(--c-muted); }
.nav__links a:hover { color: var(--c-accent); }
.nav__cta { margin-left: auto; }
@media (min-width: 880px) {
  .nav__links { display: inline-flex; }
  .nav__cta { margin-left: 0; }
}

/* ─── Hero ──────────────────────────────────────── */
.hero {
  position: relative;
  padding: 90px 0 70px;
  overflow: hidden;
}
.hero__bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(60rem 30rem at 80% -10%, rgba(37, 99, 235, 0.10), transparent 60%),
    radial-gradient(40rem 24rem at -10% 110%, rgba(99, 102, 241, 0.08), transparent 60%),
    linear-gradient(180deg, #f8fafc 0%, #ffffff 80%);
  z-index: -1;
}
.hero__bg::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(15, 23, 42, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(15, 23, 42, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, black 50%, transparent 100%);
}
.hero__inner { position: relative; }
.hero__eyebrow {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--c-tag-bg);
  color: var(--c-tag-fg);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin: 0 0 22px;
}
.hero__title {
  font-size: clamp(2.1rem, 4.6vw, 3.6rem);
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 22px;
}
.hero__title-accent {
  background: linear-gradient(120deg, var(--c-accent), #6366f1 60%, #a855f7);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__lead {
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  color: var(--c-muted);
  max-width: 820px;
  margin: 0 0 28px;
}
.hero__lead strong { color: var(--c-fg); }
.hero__actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 50px; }
.hero__metrics {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 740px;
}
@media (min-width: 720px) {
  .hero__metrics { grid-template-columns: repeat(4, 1fr); }
}
.hero__metrics li {
  padding: 18px 16px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.7);
}
.metric__num {
  display: block;
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--c-accent);
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.metric__num small { font-size: 0.7em; color: var(--c-accent); }
.metric__label { display: block; font-size: 0.82rem; color: var(--c-muted); margin-top: 4px; }

/* ─── Sections ──────────────────────────────────── */
.section { padding: var(--space-section) 0; }
.section--alt { background: var(--c-bg-alt); }
.section--cta { background: var(--c-bg-cta); color: #fff; padding: 70px 0; }

.section__head { max-width: 760px; margin: 0 auto 40px; text-align: center; }
.section__kicker {
  display: inline-block;
  padding: 5px 11px;
  border: 1px solid var(--c-line-2);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--c-muted);
  letter-spacing: 0.05em;
  margin-bottom: 14px;
}
.section__title {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}
.section__lead {
  color: var(--c-muted);
  font-size: 1rem;
  margin: 0;
}

/* ─── Profile (인물 카드) ──────────────────────── */
.profile-card {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin: 0 0 36px;
  padding: 32px;
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
@media (min-width: 760px) {
  .profile-card {
    grid-template-columns: 240px 1fr;
    gap: 36px;
    align-items: start;
  }
}
.profile-card__photo-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}
.profile-card__photo {
  width: 200px;
  height: 240px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--c-line);
  box-shadow: var(--shadow-md);
  background: #fff;
}
@media (min-width: 760px) {
  .profile-card__photo {
    width: 100%;
    max-width: 240px;
    height: 288px;
  }
}
.profile-card__chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
}
.profile-card__chip {
  padding: 4px 10px;
  background: var(--c-tag-bg);
  color: var(--c-tag-fg);
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}
.profile-card__bio h3 {
  margin: 0 0 4px;
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.profile-card__role {
  display: block;
  margin: 0 0 16px;
  font-size: 0.95rem;
  color: var(--c-accent);
  font-weight: 600;
}
.profile-card__bio p {
  margin: 0 0 12px;
  font-size: 0.96rem;
  color: var(--c-fg);
  line-height: 1.78;
}
.profile-card__bio p:last-child {
  margin-bottom: 0;
}

/* ─── About ─────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
@media (min-width: 720px) { .about-grid { grid-template-columns: repeat(2, 1fr); } }
.about__card {
  padding: 26px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.about__card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.about__card h3 {
  margin: 0 0 10px;
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--c-fg);
}
.about__card h3::before {
  content: "▸";
  color: var(--c-accent);
  margin-right: 6px;
}
.about__card p { margin: 0; color: var(--c-muted); font-size: 0.95rem; line-height: 1.7; }

/* ─── Skills ────────────────────────────────────── */
.skills {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}
@media (min-width: 720px) { .skills { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1000px) { .skills { grid-template-columns: repeat(3, 1fr); } }
.skill-group {
  padding: 22px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}
.skill-group h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 14px;
  font-size: 0.98rem;
  font-weight: 700;
}
.skill-group ul { display: flex; flex-wrap: wrap; gap: 8px; }
.skill-group ul li {
  padding: 5px 10px;
  background: var(--c-bg-alt);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  font-size: 0.83rem;
  font-family: var(--font-mono);
  color: var(--c-fg);
}
.badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  background: var(--c-line);
  color: var(--c-muted);
}
.badge--primary { background: var(--c-accent); color: #fff; }

/* ─── Project ───────────────────────────────────── */
.project {
  margin: 0 0 28px;
  padding: 28px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}
.section--alt .project { background: #fff; }
.project__head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 20px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.project__index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-accent);
  background: var(--c-tag-bg);
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
}
.project__title {
  margin: 0 0 4px;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.project__sub { margin: 0; color: var(--c-muted); font-size: 0.92rem; }
.project__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  font-size: 0.85rem;
  color: var(--c-muted);
  padding: 12px 14px;
  background: var(--c-bg-alt);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}
.project__meta b { color: var(--c-fg); margin-right: 4px; font-weight: 600; }
.project__stack {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 18px;
}
.project__stack span {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 4px 9px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--c-fg);
}
.project__desc {
  font-size: 0.97rem;
  line-height: 1.75;
  margin-bottom: 18px;
  color: var(--c-fg);
}
.project__desc code {
  background: var(--c-tag-bg);
  color: var(--c-accent-2);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.88em;
}
.project__diagram {
  margin: 22px 0;
  padding: 22px 18px;
  background: #fcfdff;
  border: 1px dashed var(--c-line-2);
  border-radius: var(--radius);
}
.project__diagram-title {
  margin: 0 0 14px;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--c-muted);
  letter-spacing: 0.02em;
}
.mermaid {
  margin: 0;
  font-family: var(--font-sans);
  text-align: center;
}
.project__highlights h4 {
  margin: 16px 0 10px;
  font-size: 0.95rem;
  font-weight: 700;
}
.project__highlights ul li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 6px;
  font-size: 0.95rem;
  color: var(--c-fg);
}
.project__highlights ul li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--c-accent);
}
.project__highlights code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--c-bg-alt);
  padding: 2px 6px;
  border-radius: 4px;
}
.endpoints { font-family: var(--font-mono); font-size: 0.86rem; }
.http {
  display: inline-block;
  padding: 1px 7px;
  border-radius: 4px;
  font-size: 0.76rem;
  font-weight: 700;
  margin-right: 6px;
}
.http--get { background: #ecfdf5; color: #16a34a; }
.http--post { background: var(--c-tag-bg); color: var(--c-accent); }

/* ─── Trouble ──────────────────────────────────── */
.trouble {
  margin-bottom: 36px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--c-line);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.trouble__head {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 22px 26px;
  background: linear-gradient(95deg, #0f172a, #1e293b);
  color: #fff;
  flex-wrap: wrap;
}
.trouble__index {
  font-family: var(--font-mono);
  background: var(--c-accent);
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
}
.trouble__title { margin: 0; font-size: 1.18rem; font-weight: 700; flex: 1; }
.trouble__tag {
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.18);
  padding: 4px 9px;
  border-radius: 999px;
  font-weight: 600;
}
.trouble__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--c-line);
}
@media (min-width: 880px) {
  .trouble__grid { grid-template-columns: 1fr 1fr; }
}
.trouble__col { padding: 24px 26px; background: #fff; }
.trouble__col h4 {
  margin: 0 0 12px;
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.trouble__col ul li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 6px;
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--c-fg);
}
.trouble__col ul li::before {
  content: "•";
  position: absolute;
  left: 4px;
  color: var(--c-muted);
}
.trouble__col code {
  background: var(--c-bg-alt);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.88em;
  color: var(--c-accent-2);
}
.trouble__col--problem h4::before { content: ""; }
.trouble__col--problem { background: #fffbeb; }
.trouble__col--analysis { background: #f0f9ff; }
.trouble__col--solution { background: #f5f3ff; }
.trouble__col--result { background: #ecfdf5; }

.code {
  margin: 10px 0 14px;
  padding: 14px 16px;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  line-height: 1.6;
  overflow-x: auto;
}
.code code { background: none; color: inherit; padding: 0; }

.results { margin-top: 8px; }
.results li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 14px;
  align-items: center;
  padding: 10px 14px;
  background: #fff;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  padding-left: 14px !important;
}
.results li::before { display: none; }
.result-num {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--c-success);
  min-width: 56px;
  text-align: center;
}
.result-num small { font-size: 0.7em; }
.trouble__lesson {
  margin: 16px 0 0;
  padding: 12px 14px;
  font-size: 0.88rem;
  color: var(--c-muted);
  background: #fff;
  border-left: 3px solid var(--c-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  line-height: 1.7;
}
.trouble__lesson b { color: var(--c-fg); }

/* ─── Timeline ──────────────────────────────────── */
.timeline {
  position: relative;
  list-style: none;
  padding: 0;
  margin: 0;
  max-width: 800px;
  margin: 0 auto;
}
.timeline::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 9px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-accent), var(--c-line-2));
}
.timeline__item { position: relative; padding-left: 36px; margin-bottom: 28px; }
.timeline__dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 20px;
  height: 20px;
  background: #fff;
  border: 3px solid var(--c-accent);
  border-radius: 50%;
}
.timeline__dot--secondary { border-color: var(--c-line-2); }
.timeline__body header {
  display: flex; flex-wrap: wrap; align-items: baseline;
  gap: 12px; margin-bottom: 6px;
}
.timeline__body h3 { margin: 0; font-size: 1.08rem; font-weight: 700; }
.timeline__period {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--c-muted);
  background: var(--c-bg-alt);
  padding: 2px 8px;
  border-radius: 4px;
}
.timeline__domain { margin: 0 0 8px; color: var(--c-muted); font-style: italic; font-size: 0.9rem; }
.timeline__body ul li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 5px;
  font-size: 0.92rem;
  color: var(--c-fg);
}
.timeline__body ul li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--c-accent);
}

/* ─── Contact ───────────────────────────────────── */
.contact { text-align: center; }
.contact__title { color: #fff; }
.contact__lead { color: rgba(255, 255, 255, 0.7); font-size: 1.05rem; margin: 0 0 30px; }
.contact__links { display: inline-flex; gap: 14px; flex-wrap: wrap; justify-content: center; }
.section--cta .btn--ghost {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.3);
}
.section--cta .btn--ghost:hover {
  background: rgba(255, 255, 255, 0.08);
  color: #fff;
  border-color: #fff;
}

/* ─── Footer ────────────────────────────────────── */
.footer {
  background: var(--c-bg-cta);
  color: rgba(255, 255, 255, 0.55);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}
.footer__inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding: 24px;
  font-size: 0.82rem;
}

/* ─── Print ─────────────────────────────────────── */
@media print {
  .nav, .hero__bg, .section--cta, .footer { display: none; }
  body { background: #fff; }
  .project, .trouble { break-inside: avoid; box-shadow: none; }
}