/* ========== ธีมที่ 4: อลังการ / AI Tech ========== */
:root {
  --t4-bg-deep: #0a0e17;
  --t4-bg-card: rgba(15, 23, 42, 0.6);
  --t4-glass: rgba(255, 255, 255, 0.05);
  --t4-glass-border: rgba(255, 255, 255, 0.1);
  --t4-accent: #06b6d4;
  --t4-accent-2: #8b5cf6;
  --t4-glow: rgba(6, 182, 212, 0.4);
  --t4-text: #e2e8f0;
  --t4-text-muted: #94a3b8;
}

.t4-body {
  font-family: 'Sarabun', 'IBM Plex Sans Thai', sans-serif;
  background: var(--t4-bg-deep);
  color: var(--t4-text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* พื้นหลัง gradient + grid ลาย AI */
.t4-body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: 
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(6, 182, 212, 0.15), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(139, 92, 246, 0.08), transparent),
    radial-gradient(ellipse 60% 40% at 0% 80%, rgba(6, 182, 212, 0.06), transparent),
    linear-gradient(180deg, #0a0e17 0%, #0f172a 50%, #0a0e17 100%);
  pointer-events: none;
  z-index: 0;
}
.t4-body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: 
    linear-gradient(rgba(6, 182, 212, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(6, 182, 212, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  z-index: 0;
}

/* ดาว / Starfield พื้นหลังอลังการ */
.t4-stars {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}
.t4-stars::before,
.t4-stars::after {
  content: '';
  position: absolute;
  inset: 0;
  background-repeat: repeat;
  background-size: 100% 100%;
  opacity: 0.9;
}
.t4-stars::before {
  background-image:
    radial-gradient(1.5px 1.5px at 5% 8%, rgba(255,255,255,0.95), transparent),
    radial-gradient(1px 1px at 12% 22%, rgba(255,255,255,0.8), transparent),
    radial-gradient(2px 2px at 18% 5%, rgba(6,182,212,0.9), transparent),
    radial-gradient(1px 1px at 25% 35%, rgba(255,255,255,0.7), transparent),
    radial-gradient(1.5px 1.5px at 32% 12%, rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px at 40% 48%, rgba(139,92,246,0.6), transparent),
    radial-gradient(2px 2px at 48% 28%, rgba(255,255,255,0.9), transparent),
    radial-gradient(1px 1px at 55% 55%, rgba(255,255,255,0.75), transparent),
    radial-gradient(1.5px 1.5px at 62% 18%, rgba(6,182,212,0.7), transparent),
    radial-gradient(1px 1px at 70% 42%, rgba(255,255,255,0.8), transparent),
    radial-gradient(2px 2px at 78% 8%, rgba(255,255,255,0.9), transparent),
    radial-gradient(1px 1px at 85% 65%, rgba(139,92,246,0.5), transparent),
    radial-gradient(1.5px 1.5px at 92% 32%, rgba(255,255,255,0.85), transparent),
    radial-gradient(1px 1px at 8% 58%, rgba(255,255,255,0.7), transparent),
    radial-gradient(2px 2px at 22% 72%, rgba(6,182,212,0.6), transparent),
    radial-gradient(1px 1px at 38% 88%, rgba(255,255,255,0.75), transparent),
    radial-gradient(1.5px 1.5px at 52% 78%, rgba(255,255,255,0.8), transparent),
    radial-gradient(1px 1px at 68% 92%, rgba(255,255,255,0.65), transparent),
    radial-gradient(2px 2px at 88% 85%, rgba(139,92,246,0.5), transparent);
}
.t4-stars::after {
  background-image:
    radial-gradient(1px 1px at 3% 42%, rgba(255,255,255,0.6), transparent),
    radial-gradient(1.5px 1.5px at 15% 68%, rgba(255,255,255,0.7), transparent),
    radial-gradient(1px 1px at 28% 15%, rgba(255,255,255,0.5), transparent),
    radial-gradient(2px 2px at 45% 62%, rgba(6,182,212,0.5), transparent),
    radial-gradient(1px 1px at 58% 38%, rgba(255,255,255,0.6), transparent),
    radial-gradient(1.5px 1.5px at 72% 72%, rgba(255,255,255,0.75), transparent),
    radial-gradient(1px 1px at 82% 25%, rgba(255,255,255,0.55), transparent),
    radial-gradient(1px 1px at 95% 52%, rgba(139,92,246,0.45), transparent);
  opacity: 0.7;
}
@keyframes t4-twinkle {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}
.t4-stars::before { animation: t4-twinkle 4s ease-in-out infinite; }
.t4-stars::after { animation: t4-twinkle 5s ease-in-out infinite 1s; }

.t4-body > * { position: relative; z-index: 1; }

/* Header glass */
.t4-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--t4-glass-border);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}
.t4-header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}
.t4-logo {
  font-weight: 700;
  font-size: 1.2rem;
  color: #fff;
  text-decoration: none;
  background: linear-gradient(135deg, var(--t4-accent), var(--t4-accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.02em;
}
.t4-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
}
.t4-nav a {
  color: var(--t4-text-muted);
  text-decoration: none;
  padding: 0.5rem 0.85rem;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s, background 0.2s, box-shadow 0.2s;
}
.t4-nav a:hover {
  color: var(--t4-accent);
  background: var(--t4-glass);
}
.t4-nav a.t4-active {
  color: #fff;
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.25), rgba(139, 92, 246, 0.2));
  box-shadow: 0 0 20px var(--t4-glow);
}
.t4-nav-check { display: none; }
.t4-ham {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}
.t4-ham span {
  width: 24px;
  height: 2px;
  background: var(--t4-text);
  border-radius: 2px;
}

/* Main */
.t4-main { padding: 0 0 4rem; min-height: 60vh; }
.t4-hero {
  text-align: center;
  padding: 3rem 1.5rem 4rem;
  position: relative;
}
.t4-hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, var(--t4-glow) 0%, transparent 70%);
  opacity: 0.5;
  pointer-events: none;
}
.t4-hero-inner { position: relative; }
.t4-hero-img {
  width: 100px;
  height: 100px;
  object-fit: contain;
  border-radius: 20px;
  margin-bottom: 1rem;
  border: 2px solid var(--t4-glass-border);
  box-shadow: 0 0 40px var(--t4-glow);
}
.t4-hero-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin: 0 0 0.5rem;
  background: linear-gradient(135deg, #fff 0%, var(--t4-accent) 50%, var(--t4-accent-2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.02em;
}
.t4-hero-desc {
  font-size: 1.05rem;
  color: var(--t4-text-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.6;
}

/* Cards glass */
.t4-content { max-width: 1000px; margin: 0 auto; padding: 0 1.5rem; }
.t4-block {
  background: var(--t4-bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--t4-glass-border);
  border-radius: 20px;
  padding: 2rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  transition: transform 0.3s, box-shadow 0.3s;
}
.t4-block:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 40px rgba(6, 182, 212, 0.1);
}
.t4-block-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 1rem;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.t4-block-title::before {
  content: '';
  width: 4px;
  height: 1.2em;
  background: linear-gradient(180deg, var(--t4-accent), var(--t4-accent-2));
  border-radius: 4px;
}
.t4-block-text, .t4-block p { color: var(--t4-text-muted); line-height: 1.8; margin: 0 0 1rem; }
.t4-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 1rem;
}
.t4-card {
  background: var(--t4-glass);
  border: 1px solid var(--t4-glass-border);
  border-radius: 16px;
  padding: 1.25rem;
  text-align: center;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.t4-card:hover {
  border-color: var(--t4-accent);
  box-shadow: 0 0 24px var(--t4-glow);
}
.t4-card-num {
  display: block;
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--t4-accent);
  margin-bottom: 0.25rem;
}
.t4-card-label { font-size: 0.9rem; color: var(--t4-text-muted); }
.t4-list { list-style: none; padding: 0; margin: 0; }
.t4-list li { margin-bottom: 0.5rem; }
.t4-list a {
  color: var(--t4-text);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0;
  transition: color 0.2s;
}
.t4-list a:hover { color: var(--t4-accent); }
.t4-list a::before { content: '›'; color: var(--t4-accent); font-weight: 700; }
.t4-more {
  display: inline-block;
  margin-top: 1rem;
  color: var(--t4-accent);
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s;
}
.t4-more:hover { opacity: 0.9; }
.t4-btns { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1rem; }
.t4-btn {
  display: inline-block;
  padding: 0.6rem 1.25rem;
  background: linear-gradient(135deg, var(--t4-accent), var(--t4-accent-2));
  color: #fff !important;
  text-decoration: none;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.t4-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--t4-glow);
}

/* PM2.5 / Air Quality Widget — ตัวแสดงค่า PM / อากาศ ให้เห็นชัด */
.t4-air-wrap {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.2), rgba(139, 92, 246, 0.15));
  border: 2px solid rgba(6, 182, 212, 0.4);
  border-radius: 20px;
  padding: 1.75rem 2rem;
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 0 40px rgba(6, 182, 212, 0.2), inset 0 0 60px rgba(6, 182, 212, 0.05);
}
.t4-air-wrap::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 240px;
  height: 240px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.25) 0%, transparent 70%);
}
.t4-air-wrap .t4-air-grid {
  position: relative;
  z-index: 1;
}
.t4-air-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}
.t4-air-head h3 {
  margin: 0;
  font-size: 1.15rem;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.t4-air-head h3 span { font-size: 1.25rem; }
.t4-air-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  align-items: stretch;
}
.t4-air-item {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(6, 182, 212, 0.2);
  border-radius: 14px;
  padding: 1.25rem;
  text-align: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}
.t4-air-item .label { font-size: 0.85rem; color: var(--t4-text-muted); margin-bottom: 0.35rem; display: block; }
.t4-air-item .value { font-size: 2rem; font-weight: 800; color: var(--t4-accent); display: inline; letter-spacing: 0.02em; }
.t4-air-item .unit { font-size: 0.85rem; color: var(--t4-text-muted); margin-left: 4px; }
.t4-air-aqi { font-size: 1.15rem; margin-top: 0.6rem; color: #e2e8f0; font-weight: 600; }
.t4-air-aqi-card .value { font-size: 2rem; }
@media (max-width: 560px) {
  .t4-air-grid { grid-template-columns: 1fr; }
}
.t4-air-loading { color: var(--t4-text-muted); padding: 1rem 0; min-height: 60px; display: flex; align-items: center; }
.t4-air-error { color: #f87171; font-size: 0.95rem; padding: 1rem 0; }
.t4-air-retry {
  margin-top: 1rem;
  padding: 0.6rem 1.25rem;
  background: linear-gradient(135deg, var(--t4-accent), var(--t4-accent-2));
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.t4-air-retry:hover { transform: translateY(-2px); box-shadow: 0 8px 24px var(--t4-glow); }
.t4-air-retry:disabled { opacity: 0.7; cursor: wait; }
.t4-air-updated { font-size: 0.8rem; color: var(--t4-text-muted); margin-top: 0.75rem; }

/* โคนอน รายละเอียด */
.t4-detail-hero {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.15), rgba(139, 92, 246, 0.1));
  border: 1px solid var(--t4-glass-border);
  border-radius: 20px;
  padding: 2rem;
  margin-bottom: 1.5rem;
}
.t4-detail-section h4 {
  font-size: 1rem;
  color: var(--t4-accent);
  margin: 1.25rem 0 0.5rem;
}
.t4-detail-section h4:first-child { margin-top: 0; }
.t4-detail-section p { margin: 0; color: var(--t4-text-muted); line-height: 1.8; }

/* Footer */
.t4-footer {
  background: rgba(10, 14, 23, 0.9);
  border-top: 1px solid var(--t4-glass-border);
  padding: 1.5rem;
  text-align: center;
  color: var(--t4-text-muted);
  font-size: 0.9rem;
}
.t4-footer a { color: var(--t4-accent); text-decoration: none; }
.t4-footer a:hover { text-decoration: underline; }

@media (max-width: 768px) {
  .t4-nav { display: none; }
  .t4-nav-check:checked ~ .t4-nav {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(10, 14, 23, 0.98);
    padding: 1rem;
    border-bottom: 1px solid var(--t4-glass-border);
  }
  .t4-ham { display: flex; }
}