/* =========================================================
   Playground Landing Page Styles
   ========================================================= */

/* Header & Navigation */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(6, 19, 22, 0.78);
  border-bottom: 1px solid rgba(41, 76, 82, 0.35);
  transition: border-color 0.2s ease;
}

.nav-inner {
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: -0.02em;
  color: #fff;
}

.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: rgba(41, 76, 82, 0.4);
  border: 1px solid rgba(83, 142, 151, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  transition: all 0.25s ease;
}

.brand:hover .brand-icon {
  border-color: var(--primary);
  box-shadow: 0 0 16px rgba(83, 142, 151, 0.4);
  transform: rotate(-3deg);
}

.brand span {
  color: var(--accent-300);
  font-weight: 400;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
}

.nav-links a:hover {
  color: var(--accent-200);
}

.nav-links a.ext-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* Hero Section */
.hero {
  padding: 105px 0 80px;
  text-align: center;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid rgba(41, 76, 82, 0.5);
  background: var(--pill-bg);
  color: var(--accent-300);
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  margin-bottom: 28px;
}

.hero h1 {
  font-size: clamp(44px, 7.5vw, 80px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.05em;
  color: #ffffff;
  margin-bottom: 22px;
}

.hero-gradient {
  background: linear-gradient(110deg, #ffffff 10%, var(--accent-200) 45%, var(--primary) 85%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

.hero p {
  max-width: 640px;
  margin: 0 auto 34px;
  color: var(--text-muted);
  font-size: 17px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  position: relative;
  z-index: 20;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  cursor: pointer;
  text-decoration: none;
  pointer-events: auto;
  user-select: none;
  -webkit-user-select: none;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.btn > * {
  pointer-events: none;
}

.btn-primary {
  background: var(--accent-100);
  color: #061316;
  border: 1px solid var(--accent-100);
  box-shadow: var(--btn-glow);
}

.btn-primary:hover {
  background: #ffffff;
  box-shadow: var(--btn-glow-hover);
  transform: translateY(-2px);
}

.btn-secondary {
  background: rgba(8, 22, 36, 0.85);
  color: var(--status-text);
  border: 1px solid rgba(41, 76, 82, 0.5);
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 4px 18px rgba(83, 142, 151, 0.15);
}

/* Section Headings */
.section-header {
  margin-bottom: 34px;
}

.section-title-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.section-bar {
  width: 32px;
  height: 4px;
  border-radius: 999px;
  background: var(--primary);
  flex-shrink: 0;
}

.section-header h2 {
  font-size: 28px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: -0.03em;
}

.section-header p {
  margin-top: 6px;
  margin-left: 46px;
  color: var(--text-muted);
  font-size: 14px;
}

/* Sections */
section {
  padding: 55px 0;
}

/* 3D Tilt Card Wrapper */
.tilt-wrap {
  perspective: 1000px;
  transform-style: preserve-3d;
}

.tilt-inner {
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.2s cubic-bezier(0.2, 0, 0.2, 1), box-shadow 0.25s ease, border-color 0.25s ease;
}

/* Feature Card (DSA Lab) */
.feature-card {
  display: grid;
  grid-template-columns: 1.35fr 0.9fr;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  overflow: hidden;
  box-shadow: var(--card-elevated-shadow);
  position: relative;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(132, 190, 194, 0.5), transparent);
  pointer-events: none;
}

.feature-main {
  padding: 42px 40px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  z-index: 10;
}

.feature-badge-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
}

.feature-main h3 {
  font-size: 32px;
  font-weight: 750;
  letter-spacing: -0.04em;
  color: #ffffff;
  margin-bottom: 12px;
}

.feature-main p {
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.7;
  max-width: 580px;
  margin-bottom: 28px;
}

.stats-row {
  display: flex;
  gap: 32px;
  margin-bottom: 34px;
  flex-wrap: wrap;
}

.stat-item strong {
  display: block;
  font-size: 24px;
  font-weight: 750;
  color: var(--accent-100);
  letter-spacing: -0.03em;
}

.stat-item span {
  font-size: 12px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Feature Side (Interactive Mock Terminal) */
.feature-side {
  background: var(--strip-bg);
  border-left: 1px solid var(--card-border);
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

.mock-window {
  background: #080e1a;
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.45);
}

.mock-header {
  background: #060b11;
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--strip-border-top);
}

.mock-dots {
  display: flex;
  gap: 6px;
}

.mock-dots span {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #253942;
}

.mock-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--accent-400);
}

.mock-body {
  padding: 18px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
}

.mock-step {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
  color: var(--status-text);
}

.mock-step-num {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  background: rgba(41, 76, 82, 0.4);
  border: 1px solid rgba(83, 142, 151, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  color: var(--accent-300);
  flex-shrink: 0;
}

.mock-array {
  display: flex;
  gap: 6px;
  margin: 16px 0;
}

.mock-cell {
  flex: 1;
  height: 34px;
  background: #0b1522;
  border: 1px solid rgba(83, 142, 151, 0.25);
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: #9cc2c8;
  font-weight: 600;
}

.mock-cell.active {
  background: rgba(41, 76, 82, 0.6);
  border-color: var(--primary);
  color: #fff;
  box-shadow: 0 0 10px rgba(83, 142, 151, 0.3);
}

.mock-cell.match {
  background: rgba(52, 211, 153, 0.2);
  border-color: #34d399;
  color: #6ee7b7;
}

.mock-console {
  margin-top: 14px;
  padding: 10px 12px;
  border-radius: 6px;
  background: #05090f;
  border-left: 3px solid var(--primary);
  font-size: 11px;
  color: var(--accent-300);
}

/* Cards Grid */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 100%;
  position: relative;
  transition: all 0.25s ease;
}

.card:hover {
  border-color: var(--card-hover-border);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px -8px rgba(83, 142, 151, 0.2);
}

.tilt-wrap .card:hover {
  transform: none;
}

.card-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: rgba(41, 76, 82, 0.3);
  border: 1px solid rgba(83, 142, 151, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 20px;
  color: var(--accent-300);
  transition: all 0.25s ease;
}

.card:hover .card-icon-wrap {
  border-color: var(--primary);
  box-shadow: 0 0 14px rgba(83, 142, 151, 0.3);
}

.card h3 {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #ffffff;
  margin-bottom: 10px;
}

.card p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 22px;
  flex-grow: 1;
}

.card ol {
  margin: 12px 0 14px 28px;
  padding-left: 6px;
}

.card ol li {
  margin-bottom: 8px;
  line-height: 1.65;
  color: #cbd5e1;
  font-size: 14px;
}

.card strong,
.card b {
  color: #ffffff;
  font-weight: 600;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  border-top: 1px solid rgba(41, 76, 82, 0.3);
  position: relative;
  z-index: 10;
}

.card-interactive {
  cursor: pointer;
}

.card-interactive:hover {
  border-color: rgba(132, 190, 194, 0.55);
}

.status-upcoming {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--status-text);
}

/* Coming Strip */
.coming-banner {
  margin-top: 24px;
  padding: 24px 30px;
  border: 1px dashed rgba(41, 76, 82, 0.7);
  border-radius: 14px;
  text-align: center;
  background: rgba(8, 22, 36, 0.4);
  color: var(--text-muted);
  font-size: 14px;
}

.coming-banner strong {
  color: var(--accent-200);
  font-weight: 600;
}

.coming-tags {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 12px;
  flex-wrap: wrap;
}

/* About Section */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.about-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 32px;
  position: relative;
}

.about-card h3 {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.about-card p {
  color: var(--text-muted);
  font-size: 15px;
  line-height: 1.7;
}

/* Footer */
footer {
  margin-top: 60px;
  padding: 45px 0 55px;
  border-top: 1px solid rgba(41, 76, 82, 0.35);
  color: var(--text-muted);
  font-size: 13px;
}

.footer-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-links {
  display: flex;
  align-items: center;
  gap: 20px;
}

.footer-links a:hover {
  color: var(--accent-200);
}

/* Responsive */
@media (max-width: 900px) {
  .feature-card {
    grid-template-columns: 1fr;
  }
  .feature-side {
    border-left: 0;
    border-top: 1px solid var(--card-border);
    padding: 28px;
  }
  .cards-grid {
    grid-template-columns: 1fr 1fr;
  }
  .about-grid {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 75px 0 60px;
  }
}

@media (max-width: 600px) {
  .container {
    width: min(var(--max-w), calc(100% - 32px));
  }
  .cards-grid {
    grid-template-columns: 1fr;
  }
  .feature-main {
    padding: 30px 24px;
  }
  .stats-row {
    gap: 20px;
  }
  .nav-links a:not(.ext-link) {
    display: none;
  }
  .hero h1 {
    font-size: 42px;
  }
}