/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #080c14;
  --bg2: #0d1420;
  --bg3: #111827;
  --surface: #141c2e;
  --surface2: #1a2540;
  --border: rgba(99,179,237,0.12);
  --border2: rgba(255,255,255,0.07);
  --text: #e8edf5;
  --text2: #8b9ab5;
  --text3: #5a6a85;
  --accent: #63b3ed;
  --accent2: #4299e1;
  --accent-glow: rgba(99,179,237,0.25);
  --purple: #a78bfa;
  --orange: #fb923c;
  --gold: #f6c90e;
  --green: #48bb78;
  --red: #fc8181;
  --yellow: #f6e05e;
  --radius: 16px;
  --radius-sm: 8px;
  --shadow: 0 4px 32px rgba(0,0,0,0.5);
  --shadow-lg: 0 16px 64px rgba(0,0,0,0.7);
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans KR', 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== GRADIENT TEXT ===== */
.gradient-text {
  background: linear-gradient(135deg, var(--accent) 0%, var(--purple) 60%, var(--orange) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== SECTION LABELS ===== */
.section-label {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid var(--border);
  padding: 4px 14px;
  border-radius: 100px;
  margin-bottom: 16px;
  background: rgba(99,179,237,0.06);
}

.section-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-desc {
  color: var(--text2);
  font-size: 17px;
  margin-bottom: 48px;
}

/* ===== BUTTONS ===== */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--accent2) 0%, #667eea 100%);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  padding: 14px 28px;
  border-radius: 100px;
  border: none;
  cursor: pointer;
  transition: all 0.25s;
  box-shadow: 0 4px 20px rgba(99,179,237,0.3);
  letter-spacing: -0.01em;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(99,179,237,0.45);
  filter: brightness(1.1);
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  color: var(--text2);
  font-weight: 500;
  font-size: 15px;
  padding: 14px 24px;
  border-radius: 100px;
  border: 1px solid var(--border2);
  cursor: pointer;
  transition: all 0.25s;
}
.btn-ghost:hover {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border);
}

/* ===== NAV ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 16px 0;
  transition: all 0.3s;
}
.nav.scrolled {
  background: rgba(8,12,20,0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border2);
  padding: 12px 0;
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-logo img {
  height: 28px;
  width: auto;
  filter: brightness(10);
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--text2);
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }
.nav-links a.nav-active {
  color: var(--accent);
  font-weight: 600;
}
.nav-links a.nav-active::after {
  content: '';
  display: block;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  margin-top: 2px;
}

/* ===== NAV AUTH ===== */
.nav-auth {
  display: flex;
  align-items: center;
  gap: 8px;
  position: relative;
}
.nav-login-btn {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  border: 1px solid rgba(99,179,237,0.3);
  padding: 7px 16px;
  border-radius: 100px;
  transition: all 0.2s;
  text-decoration: none;
  background: rgba(99,179,237,0.06);
}
.nav-login-btn:hover {
  background: rgba(99,179,237,0.14);
  border-color: rgba(99,179,237,0.5);
}
.nav-user {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  padding: 5px 10px;
  border-radius: 100px;
  border: 1px solid var(--border);
  transition: all 0.2s;
  user-select: none;
}
.nav-user:hover { border-color: var(--border2); background: rgba(255,255,255,0.04); }
.nav-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent2), var(--purple));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 800;
  color: #fff;
  flex-shrink: 0;
}
.nav-user-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  max-width: 100px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.nav-chevron { font-size: 10px; color: var(--text2); }

/* 드롭다운 메뉴 */
.nav-user-menu {
  display: none;
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background: var(--surface2, #1c2b42);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 6px;
  box-shadow: 0 12px 40px rgba(0,0,0,0.5);
  z-index: 200;
}
.nav-user-menu.open { display: block; }
.num-email {
  font-size: 11px;
  color: var(--text2);
  padding: 6px 10px 8px;
  word-break: break-all;
}
.num-divider {
  height: 1px;
  background: var(--border);
  margin: 2px 0;
}
.num-item {
  display: block;
  width: 100%;
  padding: 9px 10px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text2);
  background: transparent;
  border: none;
  border-radius: 7px;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  transition: all 0.15s;
}
.num-item:hover { background: rgba(255,255,255,0.06); color: var(--text); }

/* ===== HERO ===== */
.hero {
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding: 150px 24px 60px;
  gap: 60px;
  max-width: 1200px;
  margin: 0 auto;
}

.hero-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(99,179,237,0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99,179,237,0.04) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}
.orb1 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(99,179,237,0.18) 0%, transparent 70%);
  top: -100px; left: -100px;
}
.orb2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(167,139,250,0.15) 0%, transparent 70%);
  bottom: -50px; right: 10%;
}
.orb3 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(251,146,60,0.1) 0%, transparent 70%);
  top: 40%; right: 30%;
}

.hero-content {
  flex: 1;
  min-width: 0;
  position: relative;
  z-index: 1;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(99,179,237,0.08);
  border: 1px solid rgba(99,179,237,0.2);
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  margin-bottom: 28px;
}
.badge-dot {
  width: 6px; height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hero-title {
  font-size: clamp(36px, 5vw, 60px);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
}
.hero-sub {
  font-size: 17px;
  color: var(--text);
  line-height: 1.75;
  margin-bottom: 36px;
}
.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}
.hero-stats {
  display: flex;
  align-items: center;
  gap: 24px;
}
.stat { text-align: center; }
.stat-num {
  display: block;
  font-size: 28px;
  font-weight: 800;
  font-family: 'Inter', sans-serif;
  color: var(--accent);
  letter-spacing: -0.03em;
}
.stat-label {
  font-size: 13px;
  color: var(--text2);
  font-weight: 500;
}
.stat-divider {
  width: 1px;
  height: 36px;
  background: var(--border2);
}

/* ===== ULTRASOUND CARD (hero visual) ===== */
.hero-visual {
  flex: 0 0 50%;
  width: 50%;
  position: relative;
  z-index: 1;
}
.ultrasound-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg), 0 0 0 1px rgba(99,179,237,0.05);
  animation: floatCard 5s ease-in-out infinite;
}
@keyframes floatCard {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

/* ── Preview Case Card ── */
.preview-case-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 32px 80px rgba(0,0,0,0.6), 0 0 0 1px rgba(99,179,237,0.06);
  width: 100%;
}
.pcc-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(0,0,0,0.2);
}
.pcc-imgs {
  display: flex;
  height: 260px;
  background: #000;
  overflow: hidden;
}
.pcc-imgs img {
  flex: 1;
  width: 50%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.pcc-imgs img + img {
  border-left: 1px solid rgba(255,255,255,0.06);
}
.pcc-body {
  padding: 16px 18px 18px;
}
.pcc-choice {
  padding: 9px 13px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 12px;
  color: var(--text2);
  background: var(--surface2);
  line-height: 1.4;
}
.us-card-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border2);
  background: rgba(0,0,0,0.2);
}
.us-dot { width: 10px; height: 10px; border-radius: 50%; }
.us-dot.red { background: #fc8181; }
.us-dot.yellow { background: #f6e05e; }
.us-dot.green { background: #68d391; }
.us-title { font-size: 12px; color: var(--text3); margin-left: 6px; font-family: 'Inter', monospace; flex: 1; }
.slide-nav { display: flex; align-items: center; gap: 6px; margin-left: auto; }
.slide-btn { background: rgba(99,179,237,0.1); border: 1px solid var(--border2); color: var(--accent); width: 22px; height: 22px; border-radius: 5px; cursor: pointer; font-size: 14px; line-height: 1; display: flex; align-items: center; justify-content: center; transition: background .15s; }
.slide-btn:hover { background: rgba(99,179,237,0.2); }
.slide-indicator { font-size: 10px; color: var(--text3); font-family: 'Inter', monospace; min-width: 32px; text-align: center; }

.us-image-area {
  height: 200px;
  background: linear-gradient(180deg, #000d1a 0%, #001529 40%, #000810 100%);
  position: relative;
  overflow: hidden;
}
.us-scan-lines {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    180deg,
    transparent 0px,
    transparent 3px,
    rgba(99,179,237,0.02) 3px,
    rgba(99,179,237,0.02) 4px
  );
}
.us-image-area::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 70% at 50% 55%, rgba(99,179,237,0.08) 0%, transparent 70%),
    radial-gradient(ellipse 40% 50% at 35% 40%, rgba(200,220,255,0.06) 0%, transparent 60%),
    radial-gradient(ellipse 30% 35% at 55% 55%, rgba(150,180,220,0.12) 0%, transparent 50%),
    radial-gradient(ellipse 20% 25% at 52% 58%, rgba(99,179,237,0.25) 0%, transparent 40%);
}
.us-annotation { position: absolute; inset: 0; }
.ann-marker {
  position: absolute;
  transform: translate(-50%, -50%);
}
.ann-ring {
  width: 28px; height: 28px;
  border: 2px solid rgba(252,129,74,0.8);
  border-radius: 50%;
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%,-50%);
  animation: ringPulse 2.5s ease-in-out infinite;
}
@keyframes ringPulse {
  0%, 100% { transform: translate(-50%,-50%) scale(1); opacity: 0.8; }
  50% { transform: translate(-50%,-50%) scale(1.3); opacity: 0.4; }
}
.ann-dot {
  width: 6px; height: 6px;
  background: #fc8149;
  border-radius: 50%;
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%,-50%);
}
.ann-line {
  position: absolute;
  height: 1px;
  background: rgba(252,193,74,0.6);
}
.ann-label {
  position: absolute;
  font-size: 9px;
  color: rgba(252,193,74,0.9);
  font-family: 'Inter', monospace;
  background: rgba(0,0,0,0.6);
  padding: 2px 6px;
  border-radius: 3px;
  border: 1px solid rgba(252,193,74,0.3);
}
.us-overlay-text {
  position: absolute;
  bottom: 8px; left: 12px;
  font-size: 10px;
  font-family: 'Inter', monospace;
  color: rgba(99,179,237,0.5);
  letter-spacing: 1px;
}

.us-question { padding: 16px; }
.question-text {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}
.choices { display: flex; flex-direction: column; gap: 6px; }
.choice {
  font-size: 12px;
  color: var(--text2);
  padding: 7px 10px;
  border-radius: 6px;
  border: 1px solid var(--border2);
  transition: all 0.2s;
  cursor: pointer;
}
.choice:hover { border-color: var(--border); color: var(--text); }
.choice.active {
  border-color: rgba(99,179,237,0.5);
  background: rgba(99,179,237,0.08);
  color: var(--accent);
}
.us-footer {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  border-top: 1px solid var(--border2);
}
.tag {
  font-size: 10px;
  padding: 3px 8px;
  border-radius: 100px;
  background: rgba(99,179,237,0.08);
  border: 1px solid rgba(99,179,237,0.15);
  color: var(--accent);
  font-weight: 500;
}

/* ===== ABOUT SECTION ===== */
.about-section {
  padding: 70px 0;
  position: relative;
}
.about-section::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}
.about-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 48px;
}
.about-card {
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  padding: 32px;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}
.about-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(99,179,237,0.04) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
}
.about-card:hover {
  border-color: var(--border);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
}
.about-card:hover::before { opacity: 1; }
.about-icon { font-size: 32px; margin-bottom: 16px; }
.about-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}
.about-card p {
  font-size: 14px;
  color: var(--text);
  line-height: 1.7;
  opacity: 0.85;
}

/* ===== INSTRUCTOR SECTION ===== */
.instructor-section {
  padding: 70px 0;
  background: var(--bg2);
  position: relative;
}
.instructor-section::before, .instructor-section::after {
  content: '';
  position: absolute;
  left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}
.instructor-section::before { top: 0; }
.instructor-section::after { bottom: 0; }

.instructor-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}
.instructor-card {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  margin-top: 32px;
}
.avatar-wrapper { position: relative; flex-shrink: 0; width: 80px; height: 80px; }
.avatar-placeholder {
  width: 80px; height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent2), var(--purple));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
}
.avatar-badge {
  position: absolute;
  bottom: -8px; left: 50%;
  transform: translateX(-50%);
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 9px;
  font-weight: 600;
  color: var(--accent);
  padding: 2px 8px;
  white-space: nowrap;
}
.inst-name {
  font-size: 22px;
  font-weight: 800;
  margin-bottom: 4px;
}
.inst-role {
  font-size: 13px;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 12px;
}
.inst-bio {
  font-size: 14px;
  color: var(--text);
  opacity: 0.85;
  line-height: 1.75;
  margin-bottom: 16px;
}
.inst-links { display: flex; flex-direction: column; gap: 8px; }
.inst-link {
  font-size: 13px;
  color: var(--text2);
  transition: color 0.2s;
}
.inst-link:hover { color: var(--accent); }

.certs-section { margin-bottom: 32px; }
.certs-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 14px;
}
.certs-sub { font-weight: 400; color: var(--text2); font-size: 12px; }
.certs-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.cert-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 100px;
  background: rgba(99,179,237,0.08);
  border: 1px solid rgba(99,179,237,0.2);
  color: var(--accent);
  font-family: 'Inter', sans-serif;
}
.specialist-list { display: flex; flex-direction: column; gap: 8px; }
.specialist-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 13px;
  color: var(--text);
  padding: 8px 12px;
  border-radius: 8px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border2);
}
.specialist-item.top { border-color: rgba(246,201,14,0.15); background: rgba(246,201,14,0.04); }
.sp-rank {
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 100px;
  flex-shrink: 0;
}
.sp-rank.gold { background: rgba(246,201,14,0.15); color: var(--gold); border: 1px solid rgba(246,201,14,0.3); }
.sp-rank.silver { background: rgba(200,210,220,0.1); color: #c8d2dc; border: 1px solid rgba(200,210,220,0.2); }
.sp-rank.plain { background: rgba(255,255,255,0.08); color: var(--text2); border: 1px solid var(--border2); }

/* ===== COURSES SECTION ===== */
.courses-section {
  padding: 70px 0;
}
.courses-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.course-card {
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.35s;
  position: relative;
}
.course-card:hover {
  transform: translateY(-6px);
  border-color: var(--border);
  box-shadow: var(--shadow-lg);
}
.course-thumb {
  height: 180px;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.course-thumb.abdomen {
  background: linear-gradient(135deg, #0a1628 0%, #0d2040 50%, #0a1628 100%);
}
.course-thumb.pelvis {
  background: linear-gradient(135deg, #12102a 0%, #1a1040 50%, #12102a 100%);
}
.course-thumb.breast {
  background: linear-gradient(135deg, #1a100a 0%, #2a1508 50%, #1a100a 100%);
}
.course-scan-bg {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    180deg,
    transparent 0px,
    transparent 3px,
    rgba(255,255,255,0.015) 3px,
    rgba(255,255,255,0.015) 4px
  );
}
.course-icon-wrap {
  position: relative;
  z-index: 1;
  opacity: 0.9;
}
.course-body { padding: 20px 24px 24px; }
.course-tag {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.5px;
  padding: 3px 10px;
  border-radius: 100px;
  display: inline-block;
  margin-bottom: 10px;
}
.course-tag.open {
  background: rgba(99,179,237,0.1);
  color: var(--accent);
  border: 1px solid rgba(99,179,237,0.25);
}
.course-name {
  font-size: 19px;
  font-weight: 700;
  margin-bottom: 8px;
}
.course-desc {
  font-size: 13px;
  color: var(--text2);
  line-height: 1.65;
  margin-bottom: 14px;
}
.course-meta {
  font-size: 12px;
  color: var(--text3);
  border-top: 1px solid var(--border2);
  padding-top: 12px;
}
.more-courses {
  text-align: center;
  margin-top: 32px;
  padding: 16px;
  border: 1px dashed var(--border2);
  border-radius: var(--radius);
  font-size: 14px;
  color: var(--text3);
}

/* ===== CTA SECTION ===== */
.cta-section {
  padding: 100px 0 130px;
  position: relative;
  overflow: hidden;
  text-align: center;
  background: var(--bg2);
}
.cta-section::before {
  content: '';
  position: absolute;
  top: 0; left: 50%;
  transform: translateX(-50%);
  width: min(640px, 82%);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(99,179,237,0.55), rgba(167,139,250,0.55), transparent);
}
.cta-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.cta-inner { position: relative; z-index: 1; }
.cta-card {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  padding: 64px 48px;
  border-radius: 28px;
  background:
    radial-gradient(circle at 30% 0%, rgba(99,179,237,0.1), transparent 55%),
    radial-gradient(circle at 80% 100%, rgba(167,139,250,0.08), transparent 55%),
    var(--surface);
  border: 1px solid rgba(99,179,237,0.16);
  box-shadow:
    0 0 0 1px rgba(255,255,255,0.02) inset,
    0 40px 90px -30px rgba(99,179,237,0.28),
    0 0 120px -50px rgba(167,139,250,0.35);
}
.cta-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid rgba(99,179,237,0.25);
  background: rgba(99,179,237,0.06);
  padding: 4px 16px;
  border-radius: 100px;
  margin-bottom: 24px;
}
.cta-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
}
.cta-sub {
  font-size: 16px;
  color: var(--text2);
  line-height: 1.7;
  margin-bottom: 32px;
}
.cta-stats-mini {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 36px;
}
.cta-stat-chip {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-size: 13px;
  color: var(--text2);
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border2);
  padding: 8px 18px;
  border-radius: 100px;
}
.cta-stat-chip b { font-size: 16px; font-weight: 800; color: var(--text); }
.cta-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 14px;
}
.cta-actions .btn-primary {
  padding: 16px 36px;
  font-size: 16px;
  box-shadow: 0 8px 32px rgba(99,179,237,0.4);
}
.cta-actions .btn-ghost {
  padding: 16px 30px;
  font-size: 16px;
}
.cta-form {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 14px;
}
.cta-input {
  width: 320px;
  padding: 14px 20px;
  border-radius: 100px;
  border: 1px solid var(--border2);
  background: var(--surface);
  color: var(--text);
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s;
  font-family: inherit;
}
.cta-input:focus { border-color: var(--accent); }
.cta-input::placeholder { color: var(--text3); }
.cta-note { font-size: 12px; color: var(--text3); }

/* ===== FOOTER ===== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border2);
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
}
.footer-brand img { display: none; }
.footer-brand-text {
  font-family: 'Inter', sans-serif;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.18em;
  color: #3ecfcf;
  text-transform: uppercase;
  text-decoration: none;
}
.footer-copy { font-size: 13px; color: var(--text3); }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 13px; color: var(--text3); transition: color 0.2s; }
.footer-links a:hover { color: var(--text2); }
.footer-biz {
  max-width: 1200px;
  margin: 14px auto 0;
  padding: 14px 24px 0;
  border-top: 1px solid var(--border2);
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 5px 16px;
  font-size: 13px;
  color: var(--text2);
}
.footer-biz a { color: var(--text2); text-decoration: none; transition: color 0.2s; }
.footer-biz a:hover { color: var(--text); }

/* ===== NAV ACTIVE ===== */
.nav-links a.nav-active {
  color: var(--accent) !important;
  font-weight: 600;
}
.nav-links a.nav-active::after {
  content: '';
  display: block;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  margin-top: 2px;
}

/* ===== PAGE LAYOUT (cases / community) ===== */
.page-main { min-height: 100vh; padding-bottom: 80px; }

.page-header {
  padding: 140px 0 64px;
  text-align: center;
}
.page-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 16px;
}
.page-desc {
  font-size: 17px;
  color: var(--text);
  line-height: 1.75;
}

.cases-page-section { padding: 0 0 80px; }

/* ===== CASES CATEGORY CARDS ===== */
.cases-category-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}
.cases-cat-card {
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.35s;
}
.cases-cat-card:hover {
  border-color: var(--border);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.cases-cat-thumb {
  height: 200px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.cases-cat-thumb.abdomen { background: linear-gradient(135deg, #0a1628 0%, #0d2040 50%, #0a1628 100%); }
.cases-cat-thumb.pelvis  { background: linear-gradient(135deg, #12102a 0%, #1a1040 50%, #12102a 100%); }
.cases-cat-thumb.breast  { background: linear-gradient(135deg, #1a100a 0%, #2a1508 50%, #1a100a 100%); }

.cases-cat-label-wrap {
  position: absolute;
  top: 14px; left: 16px;
}
.cases-cat-en {
  font-size: 10px;
  font-family: 'Inter', sans-serif;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: rgba(255,255,255,0.3);
}
.cases-cat-body { padding: 20px 24px 24px; }
.cases-cat-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}
.cases-cat-name {
  font-size: 20px;
  font-weight: 700;
}
.coming-badge {
  font-size: 10px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 100px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border2);
  color: var(--text3);
}
.cases-cat-desc {
  font-size: 13px;
  color: var(--text2);
  line-height: 1.65;
  margin-bottom: 14px;
}
.cases-cat-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}
.cat-tag {
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 100px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border2);
  color: var(--text3);
}
.cases-btn {
  width: 100%;
  justify-content: center;
  opacity: 0.5;
  cursor: not-allowed;
}
.cases-btn:hover { transform: none; }

/* ===== COMING SOON CHIPS ===== */
.cases-coming-section { text-align: center; padding: 40px 0 0; }
.cases-coming-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text3);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.cases-coming-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}
.coming-chip {
  font-size: 13px;
  padding: 7px 16px;
  border-radius: 100px;
  background: rgba(255,255,255,0.03);
  border: 1px dashed var(--border2);
  color: var(--text3);
}

/* ===== COMMUNITY PAGE ===== */
.community-coming {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: 24px;
  padding: 56px 48px;
}
.community-icon { font-size: 48px; margin-bottom: 20px; }
.community-title { font-size: 28px; font-weight: 800; margin-bottom: 12px; }
.community-desc { font-size: 15px; color: var(--text2); line-height: 1.7; margin-bottom: 36px; }
.community-features { display: flex; flex-direction: column; gap: 20px; text-align: left; }
.comm-feat {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  padding: 16px 20px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border2);
  border-radius: 12px;
}
.comm-feat-icon { font-size: 22px; flex-shrink: 0; margin-top: 2px; }
.comm-feat strong { display: block; font-size: 14px; font-weight: 600; margin-bottom: 4px; }
.comm-feat p { font-size: 13px; color: var(--text2); line-height: 1.6; margin: 0; }

/* ===== RESPONSIVE ===== */
/* ===== HAMBURGER ===== */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  border-radius: 8px;
  transition: background 0.2s;
}
.nav-hamburger:hover { background: rgba(255,255,255,0.06); }
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all 0.2s;
}

/* ===== MOBILE MENU ===== */
.nav-mobile-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 300;
  backdrop-filter: blur(4px);
}
.nav-mobile-overlay.open { display: block; }
.nav-mobile-menu {
  position: fixed;
  top: 0; right: 0;
  width: 80%;
  max-width: 320px;
  height: 100%;
  background: #0d1420;
  border-left: 1px solid var(--border2);
  z-index: 400;
  transform: translateX(100%);
  transition: transform 0.3s ease;
  display: flex;
  flex-direction: column;
  padding: 0;
  overflow-y: auto;
}
.nav-mobile-menu.open { transform: translateX(0); }
.nav-mobile-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--border2);
}
.nav-mobile-close {
  background: none;
  border: none;
  color: var(--text2);
  font-size: 18px;
  cursor: pointer;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  transition: background 0.2s;
}
.nav-mobile-close:hover { background: rgba(255,255,255,0.08); color: var(--text); }
.nav-mobile-links {
  flex: 1;
  padding: 12px 12px;
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.nav-mobile-link {
  display: block;
  padding: 12px 12px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  border-radius: 10px;
  transition: background 0.15s;
  text-decoration: none;
}
.nav-mobile-link:hover, .nav-mobile-link.nav-active { background: rgba(255,255,255,0.05); color: var(--accent); }
.nav-mobile-section {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text2);
  padding: 16px 12px 6px;
  cursor: default;
}
.nav-mobile-section:hover { background: none; color: var(--text2); }
.nav-mobile-sub-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px 10px 20px;
  font-size: 14px;
  color: var(--text2);
  border-radius: 8px;
  transition: background 0.15s;
  text-decoration: none;
}
.nav-mobile-sub-link:hover { background: rgba(255,255,255,0.05); color: var(--text); }
.nav-mobile-auth {
  padding: 16px 16px 32px;
  border-top: 1px solid var(--border2);
}

/* ===== TABLET (≤1024px) ===== */
@media (max-width: 1024px) {
  .hero { flex-direction: column; text-align: center; padding-top: 120px; padding-bottom: 60px; gap: 40px; }
  .hero-visual { width: 100%; max-width: 480px; flex: none; }
  .hero-actions { justify-content: center; }
  .hero-stats { justify-content: center; }
  .instructor-layout { grid-template-columns: 1fr; }
  .instructor-card { flex-direction: column; align-items: center; text-align: center; }
  .inst-links { align-items: center; }
  .courses-grid { grid-template-columns: 1fr 1fr; }
  .about-grid { grid-template-columns: 1fr 1fr; }
  .cases-category-grid { grid-template-columns: 1fr 1fr; }
}

/* ===== MOBILE (≤640px) ===== */
@media (max-width: 640px) {
  /* nav */
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .nav-inner { padding: 0 16px; }

  /* container */
  .container { padding: 0 16px; }

  /* hero */
  .hero {
    padding: 100px 16px 60px;
    gap: 32px;
    min-height: auto;
    text-align: center;
  }
  .hero-content { width: 100%; }
  .hero-title { font-size: clamp(26px, 7vw, 40px); }
  .hero-sub { font-size: 14px; }
  .hero-sub br { display: none; }
  .hero-actions {
    justify-content: center;
    flex-direction: column;
    align-items: center;
    gap: 12px;
  }
  .hero-actions .btn-primary,
  .hero-actions .btn-ghost { width: 100%; max-width: 280px; justify-content: center; }
  .hero-stats { justify-content: center; gap: 20px; flex-wrap: wrap; }
  .hero-visual { max-width: 100%; }
  .preview-case-card { font-size: 13px; }
  .pcc-imgs { gap: 6px; }
  .pcc-imgs img { height: 140px; }

  /* sections */
  .about-section,
  .instructor-section,
  .cases-page-section { padding: 60px 0; }

  /* grids */
  .about-grid { grid-template-columns: 1fr; gap: 12px; }
  .about-card { padding: 20px; }
  .courses-grid { grid-template-columns: 1fr; }
  .cases-category-grid { grid-template-columns: 1fr; gap: 16px; }

  /* section text */
  .section-title { font-size: clamp(22px, 6vw, 32px); }
  .section-desc { font-size: 14px; margin-bottom: 32px; }
  .page-title { font-size: clamp(24px, 7vw, 36px); }
  .page-desc { font-size: 14px; }
  .page-header { padding: 100px 0 40px; }

  /* instructor */
  .instructor-card { flex-direction: column; align-items: center; text-align: center; padding: 24px 20px; }
  .inst-links { align-items: center; }
  .certs-grid { grid-template-columns: 1fr; }

  /* cases cat card */
  .cases-cat-thumb { height: 180px; }
  .cases-cat-body { padding: 20px; }
  .cases-cat-name { font-size: 18px; }
  .cases-cat-tags { flex-wrap: wrap; }

  /* coming section */
  .cases-coming-section { margin-top: 40px; }
  .cases-coming-list { gap: 8px; flex-wrap: wrap; justify-content: center; }
  .coming-chip { font-size: 12px; padding: 6px 14px; }

  /* buttons */
  .btn-primary, .btn-ghost { font-size: 14px; padding: 12px 20px; }

  /* footer */
  .footer-inner { flex-direction: column; gap: 16px; text-align: center; }
  .footer-links { justify-content: center; }

  /* community */
  .community-coming { padding: 40px 20px; }

  /* stat */
  .stat-num { font-size: clamp(20px, 5vw, 28px); }

  /* nav auth - hide name on mobile */
  .nav-user-name { display: none; }

  /* nav dropdown hide on mobile */
  .nav-has-dropdown .nav-dropdown { display: none !important; }
}

/* ===== SCROLL ANIMATIONS ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}
/* Nav dropdown */
.nav-has-dropdown { position: relative; }
.nav-arrow { font-size: 10px; opacity: 0.6; margin-left: 2px; }
.nav-dropdown {
  display: none;
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  padding-top: 12px;
  z-index: 200;
}
.nav-dropdown-inner {
  background: #0f1e30;
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 10px;
  padding: 6px;
  min-width: 190px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
}
.nav-has-dropdown:hover .nav-dropdown { display: flex; flex-direction: column; }
.nav-dd-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 12px;
  border-radius: 7px;
  font-size: 13px;
  color: var(--text2);
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
  gap: 10px;
}
.nav-dd-item:hover { background: rgba(255,255,255,0.06); color: var(--text); }
.nav-dd-badge {
  font-size: 10px;
  padding: 2px 7px;
  border-radius: 20px;
  background: rgba(255,255,255,0.07);
  color: var(--text2);
  white-space: nowrap;
}
.nav-dd-badge.open { background: rgba(62,207,207,0.15); color: #3ecfcf; }