/* =========================================
   COMPONENTS — Header, Tabs, Cards, Buttons, Modals, etc.
   ========================================= */

/* ----- Header & Nav ----- */
header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--bg-header, var(--bg));
  backdrop-filter: blur(28px);
  border-bottom: 1px solid var(--border);
  transition: var(--t-normal);
}

.hdr {
  max-width: 1240px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  padding: 0 1.4rem;
  gap: 1rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--accent), var(--accent-warm));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: .9rem;
  color: #030d17;
  box-shadow: 0 0 20px var(--accent-dim);
}

.brand-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.brand-name span {
  background: linear-gradient(120deg, var(--accent), var(--accent-warm));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.socials a {
  color: var(--text-muted);
  font-size: .92rem;
  transition: var(--t-fast);
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.socials a:hover {
  color: var(--accent);
  background: var(--accent-dim);
}

.theme-toggle {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--t-fast);
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
}

.yt-btn {
  display: flex;
  align-items: center;
  gap: .45rem;
  background: linear-gradient(135deg, #ff2d2d, #cc0000);
  color: #fff;
  border: none;
  padding: .42rem 1.1rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: .78rem;
  cursor: pointer;
  text-decoration: none;
  animation: ytPulse 2.5s ease-in-out infinite;
  box-shadow: 0 0 18px rgba(255,45,45,0.4);
}

@keyframes ytPulse {
  0%, 100% { box-shadow: 0 0 14px rgba(255,45,45,0.4); }
  50% { box-shadow: 0 0 28px rgba(255,45,45,0.65); }
}

/* ----- Tab Navigation ----- */
.tab-nav-wrap {
  position: sticky;
  top: 64px;
  z-index: 150;
  background: var(--bg);
  backdrop-filter: blur(28px);
  border-bottom: 1px solid var(--border);
}

.tab-nav {
  max-width: 1240px;
  margin: 0 auto;
  padding: .6rem 1.4rem;
  display: flex;
  gap: .3rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.tab-nav::-webkit-scrollbar { display: none; }

.tab-btn {
  padding: .44rem .95rem;
  border-radius: 10px;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text-muted);
  font-size: .78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.22s;
  display: flex;
  align-items: center;
  gap: .4rem;
  white-space: nowrap;
  position: relative;
}

.tab-btn i { font-size: .8rem; }

.tab-btn:hover:not(.active) {
  border-color: var(--border);
  color: var(--text);
  background: var(--surface);
}

.tab-btn.active {
  background: var(--accent-dim);
  color: var(--accent);
  border-color: var(--border-accent);
  font-weight: 700;
  box-shadow: 0 0 0 1px var(--border-accent);
}

.tab-btn.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  height: 2px;
  background: var(--accent);
  border-radius: 999px;
}

.tab-content {
  display: none;
  position: relative;
  z-index: 1;
}

.tab-content.active {
  display: block;
}

/* ----- Card (standard) ----- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  overflow: hidden;
  margin-bottom: 1.2rem;
  backdrop-filter: blur(8px);
  transition: var(--t-normal);
}

.card-hd {
  display: flex;
  align-items: center;
  gap: .9rem;
  padding: 1rem 1.5rem;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.step-badge {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), var(--accent-warm));
  color: #030d17;
  font-weight: 800;
  font-size: .78rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 0 12px var(--accent-dim);
}

.card-bd {
  padding: 1.4rem 1.5rem;
}

@media (max-width: 600px) {
  .card-bd { padding: 1.1rem; }
}

/* ----- Hero Section (new) ----- */
.site-hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: 120px 32px 80px;
}

.hero-glow-top {
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(ellipse, rgba(0,80,160,0.25) 0%, transparent 70%);
  pointer-events: none;
}

.hero-glow-bottom {
  position: absolute;
  bottom: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(0,212,255,0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero-inner {
  max-width: 740px;
  margin: 0 auto;
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 22px;
}

.hero-dot { color: var(--text-dim); }

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 800;
  color: #fff;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 24px;
}

.hero-accent {
  color: var(--accent);
  text-shadow: 0 0 60px rgba(0,212,255,0.4);
}

.hero-desc {
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.7;
  margin: 0 auto 36px;
  max-width: 480px;
}

.hero-cta-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  padding: 20px 32px;
  max-width: 480px;
  margin: 0 auto;
}

.hero-stat {
  flex: 1;
  text-align: center;
}

.hero-stat-num {
  display: block;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 4px;
}

.hero-stat-label {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: var(--border);
  flex-shrink: 0;
}

/* ----- Buttons ----- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-warm);
  color: #000;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  padding: 13px 28px;
  border-radius: var(--r-full);
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: var(--t-normal);
  box-shadow: 0 0 28px var(--accent-warm-dim);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 44px rgba(255,140,66,0.4);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--text);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 14px;
  padding: 13px 28px;
  border-radius: var(--r-full);
  border: 1px solid var(--border-hover);
  text-decoration: none;
  cursor: pointer;
  transition: var(--t-normal);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 20px var(--accent-dim);
}

/* ----- Chapter Dividers ----- */
.chapter-divider {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 64px 0 32px;
  border-top: 1px solid var(--border);
  max-width: 1100px;
  margin: 80px auto 0;
  padding-left: 32px;
  padding-right: 32px;
}

.ch-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  flex-shrink: 0;
}

.ch-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 3.5vw, 34px);
  color: #fff;
  line-height: 1.15;
  flex: 1;
}

.ch-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: var(--r-full);
  background: var(--accent-dim);
  color: var(--accent);
  border: 1px solid var(--border-accent);
  white-space: nowrap;
}

/* ----- Modal Styles (for frameworks & concepts) ----- */
.m-sec { margin-bottom: 1.2rem; }
.m-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-warm);
  margin-bottom: 0.4rem;
}
.m-text {
  font-size: 0.88rem;
  color: var(--text);
  line-height: 1.65;
}
.m-letters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.5rem;
}
.m-chip {
  background: rgba(255,140,66,0.1);
  border: 1px solid rgba(255,140,66,0.3);
  border-radius: 7px;
  padding: 0.35rem 0.65rem;
  font-size: 0.76rem;
}
.m-chip strong { color: var(--accent-warm); }
.m-chip span { color: var(--text-muted); margin-left: 0.25rem; }
.m-prompt {
  background: var(--surface-2);
  border: 1px solid rgba(255,140,66,0.25);
  border-left: 4px solid var(--accent-warm);
  border-radius: 0 11px 11px 0;
  padding: 0.85rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #e2d9c0;
  line-height: 1.65;
  white-space: pre-wrap;
  word-break: break-word;
}

/* ----- Footer ----- */
footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1rem;
  text-align: center;
  color: var(--text-muted);
  font-size: .82rem;
  position: relative;
  z-index: 1;
  background: var(--surface);
  backdrop-filter: blur(16px);
}

.footer-inner {
  max-width: 640px;
  margin: 0 auto;
}

.footer-brand {
  font-size: 1.1rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: .5rem;
  letter-spacing: -0.02em;
}

.footer-brand span { color: var(--accent); }

.footer-copy {
  color: var(--text-muted);
  font-size: .78rem;
  margin-top: .4rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.4rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-muted);
  font-size: .82rem;
  text-decoration: none;
  transition: var(--t-fast);
  padding: .35rem .75rem;
  border-radius: 10px;
  display: flex;
  align-items: center;
  gap: .4rem;
}

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

/* ----- Mobile fixes ----- */
@media (max-width: 640px) {
  .tab-btn span { display: none; }
  .tab-btn i { font-size: .92rem; }
  .tab-btn { padding: .44rem .75rem; }

  /* Make sure social icons are visible */
  .hdr-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }
  .socials {
    display: flex !important;
    gap: 0.5rem;
  }

  .chapter-divider {
    flex-wrap: wrap;
    gap: 8px;
    padding-left: 18px;
    padding-right: 18px;
  }
  .ch-tag { display: none; }

  .hero-stats {
    padding: 16px 20px;
    flex-direction: column;
    gap: 16px;
  }
  .hero-stat-divider {
    width: 48px;
    height: 1px;
  }
}

/* ----- Scroll progress bar (will be added by JS) ----- */
#scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent);
  z-index: 9999;
  transition: width 0.1s linear;
  pointer-events: none;
  }