/* =============================================
   CLAUDE CODE GUIDE — Samsung-inspired Style
   ============================================= */

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

:root {
  --blue:       #2189ff;
  --dark-blue:  #1428A0;
  --black:      #000000;
  --white:      #ffffff;
  --gray-50:    #f7f7f7;
  --gray-100:   #f3f3f3;
  --gray-200:   #e6e6e6;
  --gray-400:   #aaaaaa;
  --gray-500:   #767676;
  --gray-800:   #1a1a1a;
  --dark-bg:    #0a0a0f;
  --dark-card:  #141418;
  --dark-border:#242428;
  --font:       'Apple SD Gothic Neo', 'Malgun Gothic', 'Noto Sans KR', Dotum, sans-serif;
  --mono:       'SF Mono', 'Monaco', 'Consolas', 'Courier New', monospace;
  --radius:     16px;
  --radius-sm:  10px;
  --radius-btn: 100px;
  --transition: 0.25s ease;
  --shadow:     0 8px 48px rgba(0,0,0,0.08);
  --shadow-blue:0 8px 40px rgba(33,137,255,0.15);
}

html { scroll-behavior: smooth; scroll-padding-top: 64px; }

body {
  font-family: var(--font);
  color: var(--black);
  background: var(--white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ─── Container ─── */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 40px;
}

/* ─── Buttons ─── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-btn);
  font-weight: 700;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  letter-spacing: -0.2px;
  white-space: nowrap;
}
.btn-sm  { padding: 9px 22px;  font-size: 13px; }
.btn-lg  { padding: 17px 44px; font-size: 16px; }

.btn-primary         { background: var(--black); color: var(--white); border-color: var(--black); }
.btn-primary:hover   { background: #333; border-color: #333; }

.btn-outline-white       { background: transparent; color: var(--white); border-color: rgba(255,255,255,0.6); }
.btn-outline-white:hover { background: rgba(255,255,255,0.1); border-color: var(--white); }

/* ─── Header ─── */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  height: 64px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-200);
  transition: box-shadow var(--transition);
}
.header.scrolled { box-shadow: 0 2px 24px rgba(0,0,0,0.08); }

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--black);
  text-decoration: none;
  letter-spacing: -0.5px;
}

.gnb { display: flex; gap: 36px; }

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--gray-800);
  text-decoration: none;
  transition: color var(--transition);
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 2px;
  background: var(--blue);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--blue); }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

/* ─── Hero ─── */
.hero {
  min-height: 100vh;
  background: var(--dark-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: 64px;
}

.hero-glow {
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 700px;
  background: radial-gradient(ellipse at center, rgba(33,137,255,0.18) 0%, transparent 65%);
  pointer-events: none;
}

.hero-content { text-align: center; position: relative; z-index: 1; }

.hero-eyebrow {
  font-size: 16px;
  font-weight: 700;
  color: var(--blue);
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-bottom: 28px;
}

.hero-title {
  font-size: clamp(64px, 9vw, 112px);
  font-weight: 900;
  color: var(--white);
  letter-spacing: -3px;
  line-height: 1;
  margin-bottom: 28px;
}

.hero-subtitle {
  font-size: clamp(17px, 2vw, 21px);
  color: var(--gray-400);
  line-height: 1.8;
  margin-bottom: 52px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 80px;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 48px;
  justify-content: center;
  border-top: 1px solid #1e1e26;
  padding-top: 52px;
}

.stat { display: flex; flex-direction: column; align-items: center; gap: 8px; }

.stat-number {
  font-size: 40px;
  font-weight: 900;
  color: var(--blue);
  letter-spacing: -1px;
  line-height: 1;
}

.stat-label { font-size: 13px; color: var(--gray-500); letter-spacing: 0.2px; }

.stat-divider {
  width: 1px;
  height: 56px;
  background: #1e1e26;
}

.hero-scroll {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}
.scroll-dot {
  display: block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gray-500);
  animation: scroll-pulse 2s ease-in-out infinite;
}
@keyframes scroll-pulse {
  0%, 100% { opacity: 0.3; transform: translateY(0); }
  50%       { opacity: 1;   transform: translateY(6px); }
}

/* ─── Sections ─── */
.section { padding: 100px 0; }
.section-white     { background: var(--white); }
.section-gray      { background: var(--gray-50); }
.section-dark      { background: var(--dark-bg); }
.section-blue-dark { background: var(--dark-blue); }

.section-header { text-align: center; margin-bottom: 64px; }

.section-badge {
  display: inline-block;
  padding: 5px 16px;
  border-radius: var(--radius-btn);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  background: rgba(33,137,255,0.1);
  color: var(--blue);
  margin-bottom: 20px;
}
.section-badge-blue  { background: rgba(33,137,255,0.2); color: #6dc4ff; }
.section-badge-white { background: rgba(255,255,255,0.15); color: rgba(255,255,255,0.85); }

.section-title {
  font-size: clamp(34px, 4vw, 54px);
  font-weight: 900;
  letter-spacing: -1.5px;
  line-height: 1.1;
  margin-bottom: 18px;
}
.section-desc { font-size: 18px; color: var(--gray-500); line-height: 1.7; }

/* ─── Reveal Animation ─── */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ─── Diff Box ─── */
.diff-box {
  display: flex;
  align-items: stretch;
  gap: 0;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--gray-200);
  margin-bottom: 60px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}
.diff-col {
  flex: 1;
  padding: 40px;
  background: var(--gray-50);
}
.diff-col-highlight { background: var(--black); }
.diff-vs {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 24px;
  background: var(--gray-200);
  font-size: 13px;
  font-weight: 900;
  color: var(--gray-500);
  letter-spacing: 1px;
  writing-mode: vertical-rl;
}
.diff-title { font-size: 15px; font-weight: 700; margin-bottom: 20px; }
.diff-bad  { color: var(--gray-500); }
.diff-good { color: var(--blue); }
.diff-col ul { list-style: none; display: flex; flex-direction: column; gap: 12px; }
.diff-col ul li {
  font-size: 14px;
  color: var(--gray-500);
  padding-left: 20px;
  position: relative;
}
.diff-col ul li::before { content: '✕'; position: absolute; left: 0; color: #ccc; }
.diff-col-highlight ul li { color: rgba(255,255,255,0.75); }
.diff-col-highlight ul li::before { content: '✓'; color: var(--blue); }

/* ─── Feature Grid ─── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  padding: 40px 36px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  transition: all var(--transition);
}
.feature-card:hover {
  border-color: var(--blue);
  transform: translateY(-6px);
  box-shadow: var(--shadow-blue);
}
.feature-card-dark {
  background: var(--black);
  border-color: var(--black);
}
.feature-card-dark h3, .feature-card-dark p { color: rgba(255,255,255,0.85); }
.feature-card-dark p { color: var(--gray-500); }

.feature-icon { font-size: 40px; margin-bottom: 20px; }
.feature-card h3 { font-size: 19px; font-weight: 700; margin-bottom: 10px; }
.feature-card p  { font-size: 14px; color: var(--gray-500); line-height: 1.6; }

/* ─── Loop Diagram ─── */
.loop-diagram {
  max-width: 860px;
  margin: 0 auto 64px;
  text-align: center;
}
.loop-trigger, .loop-end-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}
.loop-bubble {
  display: inline-block;
  padding: 12px 32px;
  border-radius: var(--radius-btn);
  font-size: 15px;
  font-weight: 700;
}
.loop-bubble-blue { background: var(--blue); color: var(--white); }
.loop-bubble-dark { background: var(--black); color: var(--white); }

.loop-arrow-v { font-size: 22px; color: var(--gray-400); }

.loop-steps {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 20px 0;
}
.loop-step {
  flex: 1;
  padding: 32px 20px;
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  text-align: center;
}
.loop-num {
  display: block;
  font-size: 30px;
  font-weight: 900;
  color: var(--blue);
  margin-bottom: 12px;
  line-height: 1;
}
.loop-step h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.loop-step p  { font-size: 13px; color: var(--gray-500); }
.loop-conn    { font-size: 22px; color: var(--gray-400); flex-shrink: 0; }

/* ─── Example Box ─── */
.example-box {
  max-width: 680px;
  margin: 0 auto;
  background: var(--white);
  border-radius: 20px;
  padding: 48px;
  box-shadow: 0 12px 60px rgba(0,0,0,0.09);
  position: relative;
}
.example-label {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(33,137,255,0.1);
  color: var(--blue);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  border-radius: 100px;
  margin-bottom: 14px;
}
.example-box h3 { font-size: 20px; font-weight: 700; margin-bottom: 28px; }

.example-steps { display: flex; flex-direction: column; gap: 14px; margin-bottom: 28px; }
.example-step  { display: flex; align-items: center; gap: 14px; }
.step-num {
  width: 30px; height: 30px;
  border-radius: 50%;
  background: var(--blue);
  color: var(--white);
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 700;
  flex-shrink: 0;
}
.example-step span:last-child { font-size: 14px; color: var(--gray-800); }

.example-note {
  font-size: 14px;
  line-height: 1.7;
  background: rgba(33,137,255,0.06);
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--blue);
  color: var(--gray-800);
}

/* ─── Install Section ─── */
.install-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 32px;
}
.install-card {
  background: var(--dark-card);
  border: 1px solid var(--dark-border);
  border-radius: var(--radius);
  padding: 28px 32px;
}
.install-card h3 {
  font-size: 13px;
  font-weight: 600;
  color: var(--gray-500);
  margin-bottom: 14px;
  letter-spacing: 0.5px;
}
.code-block {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: #0d0d12;
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  border: 1px solid #1e1e26;
}
.code-block code {
  font-family: var(--mono);
  font-size: 13.5px;
  color: #7dd3fc;
  flex: 1;
}
.code-block-multiline { align-items: flex-start; }
.code-block-multiline code { white-space: pre; line-height: 1.8; }
.code-comment { color: #4b5563; }

.copy-btn {
  padding: 5px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  background: transparent;
  color: var(--gray-500);
  border: 1px solid var(--dark-border);
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
  font-family: var(--font);
}
.copy-btn:hover { background: var(--blue); color: var(--white); border-color: var(--blue); }
.copy-btn.copied { color: #4ade80; border-color: #4ade80; }

.login-box {
  background: var(--dark-card);
  border: 1px solid var(--dark-border);
  border-radius: 20px;
  padding: 48px;
}
.login-box h3 { font-size: 22px; font-weight: 700; color: var(--white); margin-bottom: 24px; }
.login-box .code-block { margin-bottom: 32px; }

.account-types { display: flex; gap: 20px; }
.account-type {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 22px 24px;
  background: #0d0d12;
  border-radius: var(--radius-sm);
  border: 1px solid var(--dark-border);
}
.account-icon { font-size: 26px; }
.account-type div { display: flex; flex-direction: column; gap: 4px; }
.account-type strong { font-size: 15px; font-weight: 700; color: var(--white); }
.account-type span   { font-size: 13px; color: var(--gray-500); }

/* ─── Usage Grid ─── */
.usage-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.usage-card {
  padding: 36px 32px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  transition: all var(--transition);
}
.usage-card:hover { border-color: var(--gray-400); transform: translateY(-4px); box-shadow: var(--shadow); }
.usage-icon { font-size: 36px; margin-bottom: 16px; }
.usage-card h3 { font-size: 19px; font-weight: 700; margin-bottom: 18px; }
.usage-cmds { display: flex; flex-direction: column; gap: 8px; }
.usage-cmds p {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--gray-500);
  background: var(--gray-50);
  padding: 9px 13px;
  border-radius: 6px;
}

/* ─── Tips ─── */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.tip-card {
  padding: 36px 28px;
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}
.tip-card:hover { border-color: rgba(255,255,255,0.2); }
.tip-num {
  display: block;
  font-size: 44px;
  font-weight: 900;
  color: rgba(255,255,255,0.1);
  margin-bottom: 16px;
  letter-spacing: -2px;
  line-height: 1;
}
.tip-card h3 { font-size: 16px; font-weight: 700; color: var(--white); margin-bottom: 12px; }
.tip-card p  { font-size: 13.5px; color: rgba(255,255,255,0.55); line-height: 1.75; }
.tip-card em { font-style: normal; color: rgba(255,255,255,0.35); font-family: var(--mono); font-size: 12px; }
.tip-card code {
  background: rgba(255,255,255,0.1);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 12px;
  color: #b4d8ff;
}

/* ─── Safety ─── */
.safety-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.safety-card {
  padding: 40px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
}
.safety-icon { font-size: 36px; margin-bottom: 16px; }
.safety-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.safety-card > p { font-size: 14px; color: var(--gray-500); margin-bottom: 20px; }
.safety-list { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.safety-list li { font-size: 14px; color: var(--gray-800); padding-left: 16px; position: relative; }
.safety-list li::before { content: '·'; position: absolute; left: 4px; color: var(--blue); }
.safety-list code {
  background: var(--gray-100);
  padding: 2px 7px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--dark-blue);
}
.safety-table { width: 100%; border-collapse: collapse; }
.safety-table tr { border-bottom: 1px solid var(--gray-100); }
.safety-table tr:last-child { border-bottom: none; }
.safety-table td { padding: 12px 0; font-size: 13.5px; vertical-align: top; }
.safety-table td:first-child { width: 38%; color: var(--black); padding-right: 16px; }
.safety-table td:last-child { color: var(--gray-500); }

/* ─── Commands ─── */
.commands-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}
.cmd-group h3 { font-size: 18px; font-weight: 700; margin-bottom: 20px; padding-bottom: 12px; border-bottom: 2px solid var(--black); }
.cmd-table { width: 100%; border-collapse: collapse; }
.cmd-table tr { border-bottom: 1px solid var(--gray-100); }
.cmd-table tr:last-child { border-bottom: none; }
.cmd-table td { padding: 12px 0; font-size: 13.5px; }
.cmd-table td:first-child { width: 50%; padding-right: 12px; }
.cmd-table td:last-child { color: var(--gray-500); }
.cmd-table code {
  background: var(--gray-100);
  padding: 3px 8px;
  border-radius: 5px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--dark-blue);
}

/* ─── Footer ─── */
.footer { background: var(--black); padding: 80px 0 40px; }

.footer-top {
  display: flex;
  justify-content: space-between;
  gap: 80px;
  margin-bottom: 60px;
  padding-bottom: 60px;
  border-bottom: 1px solid #1a1a1a;
}
.footer-brand { flex: 2; }
.footer-logo {
  display: block;
  font-size: 26px;
  font-weight: 900;
  color: var(--white);
  letter-spacing: -1px;
  margin-bottom: 12px;
}
.footer-brand p { font-size: 14px; color: #444; }

.footer-links-group { display: flex; gap: 60px; }
.footer-links { display: flex; flex-direction: column; gap: 10px; }
.footer-links h4 { font-size: 13px; font-weight: 700; color: var(--white); margin-bottom: 8px; letter-spacing: 0.3px; }
.footer-links a  { font-size: 13px; color: #555; text-decoration: none; transition: color var(--transition); }
.footer-links a:hover { color: var(--blue); }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.footer-bottom p   { font-size: 12px; color: #3a3a3a; }
.footer-bottom a   { color: #555; text-decoration: none; transition: color var(--transition); }
.footer-bottom a:hover { color: var(--blue); }

/* ─── Responsive ─── */
@media (max-width: 1024px) {
  .feature-grid   { grid-template-columns: repeat(2, 1fr); }
  .tips-grid      { grid-template-columns: repeat(2, 1fr); }
  .commands-grid  { grid-template-columns: repeat(2, 1fr); }
  .hero-stats     { gap: 32px; }
}

@media (max-width: 768px) {
  .container { padding: 0 24px; }
  .section   { padding: 72px 0; }

  .gnb { display: none; }
  .header-inner .btn { display: none; }

  .hero-title    { font-size: 56px; letter-spacing: -2px; }
  .hero-subtitle { font-size: 16px; }
  .hero-actions  { flex-direction: column; align-items: center; }
  .hero-stats    { flex-direction: column; gap: 24px; }
  .stat-divider  { width: 40px; height: 1px; }

  .diff-box      { flex-direction: column; }
  .diff-vs       { writing-mode: horizontal-tb; padding: 12px 0; }
  .feature-grid  { grid-template-columns: 1fr; }

  .loop-steps   { flex-direction: column; align-items: stretch; }
  .loop-conn    { transform: rotate(90deg); }

  .install-grid  { grid-template-columns: 1fr; }
  .account-types { flex-direction: column; }
  .usage-grid    { grid-template-columns: 1fr; }
  .tips-grid     { grid-template-columns: 1fr; }
  .safety-grid   { grid-template-columns: 1fr; }
  .commands-grid { grid-template-columns: 1fr; }

  .footer-top         { flex-direction: column; gap: 40px; }
  .footer-links-group { flex-wrap: wrap; gap: 32px; }
  .footer-bottom      { flex-direction: column; gap: 12px; text-align: center; }
}