:root {
  --bg: #0f1117;
  --bg-card: #1a1d27;
  --bg-card-hover: #222632;
  --accent: #6c5ce7;
  --accent-light: #a29bfe;
  --accent-glow: rgba(108, 92, 231, 0.25);
  --green: #00b894;
  --green-bg: rgba(0, 184, 148, 0.12);
  --red: #e17055;
  --red-bg: rgba(225, 112, 85, 0.12);
  --text: #e8e8ed;
  --text-dim: #9ca0b0;
  --text-muted: #6b7084;
  --border: #2a2d3a;
  --border-light: #363a4a;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Hero ── */
.back-link-top {
  display: block;
  padding: 16px 24px 0;
  font-size: 0.88rem;
  color: var(--accent-light);
  text-decoration: none;
  position: relative;
  z-index: 2;
}
.back-link-top:hover {
  text-decoration: underline;
}

.hero {
  text-align: center;
  padding: 80px 24px 60px;
  background: linear-gradient(180deg, #161826 0%, var(--bg) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

/* ── Logo shake on hover ── */
@keyframes shake {
  0%, 100% { transform: rotate(0deg); }
  10%  { transform: rotate(-6deg); }
  20%  { transform: rotate(6deg); }
  30%  { transform: rotate(-5deg); }
  40%  { transform: rotate(5deg); }
  50%  { transform: rotate(-3deg); }
  60%  { transform: rotate(3deg); }
  70%  { transform: rotate(-2deg); }
  80%  { transform: rotate(2deg); }
  90%  { transform: rotate(-1deg); }
}

.hero-logo {
  width: 250px;
  height: auto;
  margin-bottom: 28px;
  position: relative;
  filter: drop-shadow(0 0 30px var(--accent-glow));
  border-radius: 24px;
  cursor: pointer;
  transition: filter 0.3s;
}

.hero-logo:hover {
  animation: shake 0.6s ease-in-out;
  filter: drop-shadow(0 0 40px var(--accent-glow)) brightness(1.1);
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  position: relative;
}

.hero-korean-title {
  font-family: 'Yeon Sung', 'Gungsuh', 'GungSeo', '궁서체', '궁서', serif;
  font-size: 5.6rem;
  font-weight: 800;
  color: var(--accent-light);
  display: block;
  margin-bottom: 8px;
  letter-spacing: 0.08em;
  position: relative;
}

.hero h1 .sub {
  font-size: 1.1rem;
  font-weight: 400;
  color: var(--text-dim);
  display: block;
  margin-top: 4px;
}

.hero-tagline {
  font-size: 1.15rem;
  color: var(--text-dim);
  max-width: 560px;
  margin: 16px auto 0;
  position: relative;
  line-height: 1.8;
}

.free-tag {
  display: inline-block;
  background: linear-gradient(135deg, #00b894, #00cec9);
  color: #fff;
  font-weight: 800;
  padding: 1px 10px;
  border-radius: 6px;
  font-size: 1.05em;
  letter-spacing: 0.5px;
  animation: free-bounce 2s ease-in-out infinite;
  box-shadow: 0 0 12px rgba(0, 184, 148, 0.4);
}

@keyframes free-bounce {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-2px) scale(1.05); }
}

.badge-row {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 28px;
  flex-wrap: wrap;
  position: relative;
}

.badge {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
  font-weight: 500;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-dim);
}

.badge.accent {
  border-color: var(--accent);
  color: var(--accent-light);
  background: rgba(108, 92, 231, 0.1);
}

/* ── Navigation ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(15, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}

nav ul {
  display: flex;
  justify-content: center;
  gap: 32px;
  list-style: none;
  max-width: 800px;
  margin: 0 auto;
}

nav a {
  display: block;
  padding: 14px 0;
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
}

nav a:hover,
nav a.active {
  color: var(--accent-light);
}

nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform 0.2s;
}

nav a:hover::after {
  transform: scaleX(1);
}

/* ── Container ── */
.container {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── Sections ── */
section {
  padding: 72px 0;
}

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

.section-label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent-light);
  margin-bottom: 12px;
}

.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 20px;
  letter-spacing: -0.01em;
}

.section-desc {
  color: var(--text-dim);
  font-size: 1.02rem;
  line-height: 1.9;
  margin-bottom: 32px;
}

/* ── Why Section ── */
.why-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 20px;
}

.why-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  transition: background 0.2s, border-color 0.2s;
}

.why-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
}

.why-card .icon {
  font-size: 1.6rem;
  margin-bottom: 12px;
}

.why-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.why-card p {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ── Feature List ── */
.feature-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 18px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: background 0.2s, border-color 0.2s;
}

.feature-list li:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
}

.feature-icon {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.feature-icon.green { background: var(--green-bg); }
.feature-icon.purple { background: rgba(108, 92, 231, 0.12); }
.feature-icon.red { background: var(--red-bg); }

.feature-text h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.feature-text p {
  font-size: 0.88rem;
  color: var(--text-dim);
  line-height: 1.6;
}

/* ── How It Works ── */
.steps {
  counter-reset: step;
  display: flex;
  flex-direction: column;
  gap: 0;
  position: relative;
}

.steps::before {
  content: '';
  position: absolute;
  left: 19px;
  top: 24px;
  bottom: 24px;
  width: 2px;
  background: var(--border);
}

.step {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 20px 0;
  position: relative;
}

.step-num {
  counter-increment: step;
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 2px solid var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-light);
  position: relative;
  z-index: 1;
}

.step-num::after {
  content: counter(step);
}

.step-content h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.step-content p {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ── Code Block ── */
.code-block {
  background: #141620;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  margin: 20px 0;
}

.code-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: rgba(255,255,255,0.03);
  border-bottom: 1px solid var(--border);
}

.code-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.code-dot.r { background: #e17055; }
.code-dot.y { background: #fdcb6e; }
.code-dot.g { background: #00b894; }

.code-block pre {
  padding: 18px 20px;
  overflow-x: auto;
  font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--text-dim);
}

.code-block code .cmd { color: var(--green); }
.code-block code .comment { color: var(--text-muted); }
.code-block code .flag { color: var(--accent-light); }

/* ── Architecture ── */
.arch-diagram {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin: 28px 0;
}

.arch-box {
  padding: 14px 20px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  text-align: center;
  font-size: 0.88rem;
  font-weight: 500;
  min-width: 120px;
}

.arch-box.highlight {
  border-color: var(--accent);
  background: rgba(108, 92, 231, 0.08);
  color: var(--accent-light);
}

.arch-arrow {
  color: var(--text-muted);
  font-size: 1.2rem;
}

/* ── Screenshots ── */
.screenshots {
  margin-top: 32px;
}

.screenshot-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.screenshot-item {
  position: relative;
  border-radius: 14px;
  overflow: hidden;
  cursor: pointer;
}

.screenshot-item img {
  width: 100%;
  height: auto;
  object-fit: contain;
  border-radius: 14px;
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.screenshot-item:hover img {
  transform: scale(1.02);
  box-shadow: 0 8px 24px rgba(108, 92, 231, 0.2);
}

.screenshot-placeholder {
  aspect-ratio: 16/10;
  background: var(--bg-card);
  border: 2px dashed var(--border);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.88rem;
  cursor: default;
}

/* ── Screenshot lightbox overlay ── */
.screenshot-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  align-items: center;
  justify-content: center;
  cursor: pointer;
  padding: 40px;
}

.screenshot-overlay.active {
  display: flex;
}

.screenshot-overlay img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
  object-fit: contain;
}

/* ── Privacy ── */
.privacy-list {
  list-style: none;
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.privacy-list li {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.7;
}

.privacy-list .icon {
  flex-shrink: 0;
  font-size: 1.3rem;
  margin-top: 2px;
}

.privacy-list strong {
  color: var(--text);
}

.privacy-desc {
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* ── Footer ── */
footer {
  text-align: center;
  padding: 48px 24px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.85rem;
}

footer a {
  color: var(--accent-light);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* ── Responsive ── */
/* ── Privacy / Policy page ── */
.policy-body { max-width: 760px; margin: 0 auto; padding: 0 24px; }
.policy-body h2 { font-size: 1.25rem; font-weight: 700; margin-top: 36px; margin-bottom: 12px; color: var(--text); }
.policy-body h3 { font-size: 1.05rem; font-weight: 600; margin-top: 24px; margin-bottom: 8px; color: var(--text); }
.policy-body p { color: var(--text-dim); margin-bottom: 14px; font-size: 0.93rem; line-height: 1.8; }
.policy-body ul { margin: 10px 0 16px 20px; color: var(--text-dim); font-size: 0.93rem; line-height: 1.8; }
.policy-body ul li { margin-bottom: 6px; }
.policy-body strong { color: var(--text); font-weight: 600; }
.policy-body code { background: var(--bg-card); padding: 1px 6px; border-radius: 4px; font-size: 0.88rem; }
.policy-body a { color: var(--accent-light); text-decoration: none; }
.policy-body a:hover { text-decoration: underline; }
.lang-divider { border: none; border-top: 1px solid var(--border); margin: 56px 0; }
.lang-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 2px; color: var(--accent-light); margin-bottom: 32px; font-weight: 700; }
.effective-date { font-size: 0.85rem; color: var(--text-muted); margin-top: 4px; }

/* ── Responsive ── */
@media (max-width: 640px) {
  .hero { padding: 56px 20px 40px; }
  .hero h1 { font-size: 1.8rem; }
  .hero-korean-title { font-size: 3.2rem; }
  .hero-logo { width: 187px; }
  .section-title { font-size: 1.4rem; }
  .why-grid { grid-template-columns: 1fr; }
  .screenshot-grid { grid-template-columns: 1fr; }
  nav ul { gap: 16px; font-size: 0.85rem; }
  .arch-diagram { flex-direction: column; }
  .arch-arrow { transform: rotate(90deg); }
}