:root {
  --app-theme-indigo: #00CEB0;
  --app-theme-indigo-hover: #54CBAB;
  --app-theme-indigo-light: #54CBAB;
  --app-theme-indigo-lighter: rgba(96, 81, 255, 0.04);
  --app-theme-indigo-border: rgba(0, 206, 176, 0.15);
  --app-theme-indigo-border-strong: rgba(0, 206, 176, 0.8);
  --app-theme-indigo-border2: rgba(0, 206, 176, 0.3);
  --app-text-heading: #494E59;
  --app-text-body: #52638A;
  --app-text-light: #6F6F82;
  --app-surface-primary: #FFFFFF;
  --app-surface-secondary: #FAFBFF;
  --app-border-subtle: #EAEAF1;
  --app-border-hover: #DCDCE6;
  --app-elevation-small: 0 1px 3px rgba(0, 0, 0, 0.1);
  --app-elevation-medium: 0 3px 6px rgba(0, 0, 0, 0.1);
  --app-motion-quick: 0.12s ease-out;
  --app-motion-natural: 0.18s ease-out;
  --app-card-padding: 15px;
  --app-card-radius: 15px;
  --app-button-radius: 12px;
  --app-pill-radius: 100px;
}

/* ---------- BASE ---------- */
main { margin-top: 30px; }

.button-sub {
  margin: 0;
  padding: 12px 16px;
  background: var(--app-surface-primary);
  color: var(--text-color);
  border: 0.5px solid var(--app-border-subtle);
  border-radius: var(--app-pill-radius);
  font-size: 0.9em;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
  transition: background var(--app-motion-quick), border-color var(--app-motion-quick), color var(--app-motion-quick);
  letter-spacing: 0.01em;
  font-weight: 600;

  /* hint ให้ browser เตรียม compositing สำหรับปุ่มที่มี transition */
  will-change: background, color, border-color;
  backface-visibility: hidden;
}
.button-sub:hover {
  border-color: var(--app-theme-indigo-border);
  color: var(--text-primary);
}

.button-sub.active {
  color: var(--text-primary);
  border-color: var(--app-theme-indigo-light);
}

.hi { padding: 0 10px 0 10px; }
.hj { border-radius: 30px;background: #FFFFFF; border: 0.5px solid rgba(0, 0, 0, 0.1); }

.button-content {
  box-sizing: border-box;
  width: 60px !important;
  padding: 13px 19px !important;
  margin: 8px 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 23px;
  font-size: 19px;
  background: var(--app-surface-primary, #fff);
  color: var(--app-theme-indigo, #10B981);
  border: 1px solid var(--app-theme-indigo-border, #54CBAB);
  cursor: pointer;
  text-align: center;
  transition:
    border-color 0.18s,
    box-shadow 0.18s,
    transform 200ms cubic-bezier(0.4,0,0.2,1),
    color 0.18s;
  -webkit-tap-highlight-color: transparent;

  will-change: transform, border-color;
  transform: translateZ(0); /* สร้าง GPU layer สำหรับ smooth transform */
  backface-visibility: hidden;
}

.button-content:hover {
  border-color: var(--app-theme-indigo-border-strong, #54CBAB);
  transform: translateY(-1px) scale(1.008);
}

.button-content > * {
  position: relative;
  z-index: 1;
}

/* ---------- CARD ---------- */
.card {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  width: 160px;
  height: auto;
  max-height: 222px;
  max-width: 400px;
  padding: 0;
  border-radius: 30px;
  overflow: hidden;
  background: #FFFFFF;
  border: 1px solid var(--app-theme-indigo-border);
  transition:
    border-color var(--app-motion-natural),
    box-shadow var(--app-motion-natural),
    transform 200ms cubic-bezier(0.4, 0, 0.2, 1);

  /* จำกัดการ repaint ให้แคบลงเฉพาะการ์ดนี้ */
  contain: paint;
  will-change: border-color, transform;
  backface-visibility: hidden;
}
.card > * {
  position: relative;
  z-index: 1;
}
.card::before {
  content: "";
  pointer-events: none;
  position: absolute;
  z-index: 0;
  inset: 0;
  opacity: 0;
  transition: opacity 0.28s cubic-bezier(0.4,0,0.2,1);
  background: linear-gradient(
    120deg,
    rgba(247,248,255,0.13) 75%,
    rgba(96,81,255,0.10) 100%
  );
  border-radius: inherit;
}
.card:hover {
  border-color: var(--app-theme-indigo-border-strong);
}
.card-image {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 0;
  box-shadow: none;
  transition: transform 200ms cubic-bezier(0.4, 0, 0.2, 1);

  /* ปรับปรุงการแสดงภาพบนบางเบราว์เซอร์ */
  image-rendering: -webkit-optimize-contrast;
  image-rendering: crisp-edges;
  will-change: transform;
  transform: translateZ(0);
}
.card-content {
  margin-top: 5px;
  padding: 12px;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  transition: opacity 200ms cubic-bezier(0.4, 0, 0.2, 1);
  will-change: opacity;
}
.card-title {
  font-size: 13px;
  font-weight: bold;
  color: var(--app-text-heading);
  margin-bottom: 4px;
  letter-spacing: 0;
  line-height: 1.5;
}
.card-description {
  font-size: 11.3px;
  color: var(--app-text-body);
  line-height: 1.6;
  letter-spacing: 0.01em;
}

/* ---------- HORIZONTAL BUTTON CONTAINERS (ปรับ UX การเลื่อน) ---------- */
#main-buttons-container,
#sub-buttons-container {
  display: flex;
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: none;
  -ms-overflow-style: none;

  overscroll-behavior-x: contain; /* ป้องกันการ chain เลื่อนขึ้นไปยัง body */
  -webkit-overflow-scrolling: touch; /* เพิ่มความนุ่มบน iOS */
  scrollbar-gutter: stable;
}

#main-buttons-container { gap: 8px; padding: 4px; }
#main-buttons-container::-webkit-scrollbar,
#sub-buttons-container::-webkit-scrollbar { display: none; }
#sub-buttons-container { gap: 8px; padding: 5px; border-radius: 25px; }
.group-header { padding: 10px 10px; width: 100%; }
.group-header-text {
  font-size: 1.2rem;
  font-weight: 600;
  color: #464646;
}

.group-header-description {
  margin: 0.5rem 0 0;
  font-size: 1rem;
  color: var(--app-text-heading);
}

.card-content-container, 
.button-content-container {
  display: flex !important;
  flex-wrap: wrap !important;
  margin: 0 0 40px 0 !important;
  padding: 1rem 0 !important;
  background: rgba(255, 255, 255, 1);
  justify-content: center !important;
  align-items: center !important;
  border-radius: 25px;
}
.button-content-container { gap: 12px !important; }
.card-content-container { gap: 6px !important; }

.fade-in {
  opacity: 0;
  animation: fadeIn 0.25s ease-out forwards;
}
.fade-out {
  opacity: 1;
  animation: fadeOut 0.25s ease-out forwards;
}
@keyframes fadeIn {
  from { opacity: 0;}
  to   { opacity: 1; }
}
@keyframes fadeOut {
  from { opacity: 1;}
  to   { opacity: 0;}
}

@media screen and (max-width: 600px) {
  .card-content-container { justify-content: center; gap: 12px; }
  .card { margin: 8px 4px;}
  .card-content { padding-left: 10px; padding-top: 4px; }
}

/* ---------- Motion preference: ลดแอนิเมชันถ้าผู้ใช้ต้องการ ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
    will-change: auto !important;
  }
}

/* ---------- SCROLLBAR ---------- */
::-webkit-scrollbar {
  height: 7px;
  width: 7px;
  background: #f6f7fb;
  border-radius: 6px;
}
::-webkit-scrollbar-thumb {
  background: #e0e7f2;
  border-radius: 6px;
  transition: background 0.10s;
}
::-webkit-scrollbar-thumb:hover {
  background: #c8d0e7;
}

@media (max-width: 450px) {
  .container {
    padding-left: 0.7rem;
    padding-right: 0.7rem;
    border-radius: 25px;
  }
}

/* ---------- IMAGE WRAPPER ---------- */
.img-d1 {
  padding: 0 30px 0 30px;
  z-index: -2;
}
.img-d1 img {
  width: 100%;
  border-radius: 25px;

  image-rendering: -webkit-optimize-contrast;
  image-rendering: crisp-edges;
  contain: paint;
}

/* ---------- SAFETY NOTE ----------
   - ใส่ will-change / contain เฉพาะจุดสำคัญเพื่อลด memory overhead
   - การปรับปรุงทั้งหมดนี้ไม่เปลี่ยนสี, ขนาด, layout หรือ visual design ขององค์ประกอบใด ๆ
*/