/* index.css | เฉพาะหน้า index.html (หน้า intro ก่อนเข้าเว็บ) */

:root {
  --maroon: #800000;
  --maroon-dark: #3a0505;
  --gold: #ffd966;
  --blue: #1565c0;
}

html, body { height: 100%; margin: 0; }
body {
  font-family: 'Prompt', sans-serif;
  color: #fff;
  background: #120202;
  overflow: hidden;
}

/* ===== พื้นหลัง ===== */
.stage {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
/* ใส่ภาพอาคารวิทยาลัยได้ที่นี่ (ถ้าไม่มีไฟล์ จะเห็นแค่ไล่สี) */
.bg-photo {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(18,2,2,.92), rgba(80,8,8,.78) 55%, rgba(11,47,99,.80)),
    url("../../images/intro-bg.jpg") center / cover no-repeat;
  transform: scale(1.08);
  animation: slowZoom 18s ease-in-out infinite alternate;
}
@keyframes slowZoom { to { transform: scale(1.18); } }

/* ลูกแสงลอย */
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: .45;
  animation: float 12s ease-in-out infinite alternate;
}
.orb.o1 { width: 420px; height: 420px; background: #b30000; top: -120px; left: -100px; }
.orb.o2 { width: 380px; height: 380px; background: #1565c0; bottom: -120px; right: -80px; animation-delay: -4s; }
.orb.o3 { width: 260px; height: 260px; background: #d6a000; top: 40%; left: 45%; opacity: .25; animation-delay: -8s; }
@keyframes float {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(40px, -30px) scale(1.15); }
}

#particles { position: absolute; inset: 0; width: 100%; height: 100%; }

/* ===== เนื้อหา ===== */
.content {
  position: relative;
  z-index: 2;
  flex: 1;
  display: flex;
  align-items: center;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .3rem 1rem;
  border: 1px solid rgba(255, 217, 102, .5);
  border-radius: 2rem;
  color: var(--gold);
  font-size: .9rem;
  letter-spacing: .5px;
  background: rgba(255, 217, 102, .08);
  backdrop-filter: blur(4px);
}
.eyebrow .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--gold);
  animation: blink 1.4s infinite;
}
@keyframes blink { 50% { opacity: .2; } }

.headline {
  font-weight: 800;
  font-size: clamp(2rem, 4.6vw, 3.6rem);
  line-height: 1.25;
  margin: 1.2rem 0 .8rem;
  min-height: 2.6em;
  text-shadow: 0 4px 24px rgba(0, 0, 0, .5);
}
.headline .gold { color: var(--gold); }
.caret {
  display: inline-block;
  width: 3px;
  height: .95em;
  margin-left: 4px;
  vertical-align: -.1em;
  background: var(--gold);
  animation: blink .9s steps(1) infinite;
}

.subline {
  font-size: clamp(1.05rem, 1.8vw, 1.45rem);
  color: #f3dede;
  margin-bottom: 2rem;
}

/* ===== ปุ่มเข้าสู่เว็บไซต์ ===== */
.enter-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  padding: .95rem 2.4rem;
  font-family: inherit;
  font-size: 1.25rem;
  font-weight: 600;
  color: #fff;
  text-decoration: none;
  background: linear-gradient(135deg, #1565c0, #0b2f63);
  border: 2px solid rgba(255, 255, 255, .85);
  border-radius: .9rem;
  overflow: hidden;
  cursor: pointer;
  animation: glow 2.4s ease-in-out infinite;
  transition: transform .2s;
}
.enter-btn:hover { transform: translateY(-3px) scale(1.04); color: #fff; }
.enter-btn:focus-visible { outline: 3px solid var(--gold); outline-offset: 4px; }
.enter-btn .bi { transition: transform .25s; }
.enter-btn:hover .bi { transform: translateX(6px); }
/* แสงสะท้อนวิ่งผ่านปุ่ม */
.enter-btn::after {
  content: "";
  position: absolute;
  top: 0; left: -80%;
  width: 50%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, .55), transparent);
  transform: skewX(-20deg);
  animation: shine 3.2s ease-in-out infinite;
}
@keyframes shine { 0% { left: -80%; } 55%, 100% { left: 140%; } }
@keyframes glow {
  0%, 100% { box-shadow: 0 0 14px rgba(255, 217, 102, .35), 0 8px 22px rgba(0, 0, 0, .4); }
  50%      { box-shadow: 0 0 34px rgba(255, 217, 102, .8),  0 8px 22px rgba(0, 0, 0, .4); }
}

.skip-link {
  display: inline-block;
  margin-left: 1.2rem;
  color: #e8cfcf;
  font-size: .95rem;
  text-decoration: none;
  border-bottom: 1px dashed rgba(255, 255, 255, .4);
}
.skip-link:hover { color: var(--gold); }

/* ===== โลโก้ฝั่งขวา ===== */
.logo-zone { text-align: center; }
.logo-wrap {
  position: relative;
  width: clamp(200px, 26vw, 300px);
  aspect-ratio: 1;
  margin: 0 auto 1.2rem;
  display: grid;
  place-items: center;
}
.logo-wrap img {
  position: relative;
  z-index: 2;
  width: 78%;
  height: 78%;
  object-fit: contain;
  background: #fff;
  border-radius: 50%;
  padding: 1rem;
  box-shadow: 0 0 50px rgba(255, 217, 102, .45);
  animation: logoIn 1.2s cubic-bezier(.2, .9, .3, 1.2) both .3s;
}
@keyframes logoIn {
  from { opacity: 0; transform: scale(.3) rotate(-120deg); }
  to   { opacity: 1; transform: scale(1) rotate(0); }
}
.ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px dashed rgba(255, 217, 102, .7);
  animation: spin 24s linear infinite;
}
.ring.r2 {
  inset: -16px;
  border: 1px solid rgba(255, 255, 255, .25);
  border-top-color: var(--gold);
  border-bottom-color: var(--gold);
  animation-duration: 9s;
  animation-direction: reverse;
}
.ring.r3 {
  inset: -34px;
  border: 1px dotted rgba(255, 255, 255, .25);
  animation-duration: 40s;
}
@keyframes spin { to { transform: rotate(360deg); } }
/* คลื่นกระจายออกจากโลโก้ */
.pulse {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px solid rgba(255, 217, 102, .6);
  animation: pulse 3s ease-out infinite;
}
.pulse.p2 { animation-delay: 1.5s; }
@keyframes pulse { from { transform: scale(1); opacity: .8; } to { transform: scale(1.7); opacity: 0; } }

.school-th { font-size: clamp(1.3rem, 2.4vw, 1.9rem); font-weight: 700; margin: 0; line-height: 1.3; }
.school-en {
  font-size: clamp(.85rem, 1.4vw, 1.05rem);
  letter-spacing: 2px;
  color: var(--gold);
  margin: .3rem 0 0;
  text-transform: uppercase;
}

/* ===== แอนิเมชันเข้าฉากทีละส่วน ===== */
.reveal { opacity: 0; transform: translateY(28px); animation: rise .9s cubic-bezier(.2, .8, .3, 1) forwards; }
.d1 { animation-delay: .2s; } .d2 { animation-delay: .5s; }
.d3 { animation-delay: 1.4s; } .d4 { animation-delay: 1.8s; }
@keyframes rise { to { opacity: 1; transform: none; } }

/* ===== แถบท้ายหน้า ===== */
.bottom-bar {
  position: relative;
  z-index: 2;
  padding: .8rem 1rem;
  text-align: center;
  font-size: .95rem;
  background: linear-gradient(90deg, #0b47a1, #1e88e5, #0b47a1);
  background-size: 200% 100%;
  animation: slide 8s linear infinite;
}
@keyframes slide { to { background-position: 200% 0; } }

/* ===== ม่านเปลี่ยนหน้า ===== */
.curtain {
  position: fixed;
  inset: 0;
  z-index: 99;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--maroon-dark), var(--maroon));
  transform: translateY(100%);
  transition: transform .75s cubic-bezier(.77, 0, .18, 1);
}
.curtain.on { transform: translateY(0); }
.curtain img { width: 110px; background: #fff; border-radius: 50%; padding: .5rem; opacity: 0; transition: opacity .4s .35s; }
.curtain.on img { opacity: 1; }

/* ===== มือถือ ===== */
@media (max-width: 991.98px) {
  body { overflow-y: auto; }
  .stage { min-height: 100svh; }
  .content { padding: 2.5rem 0 2rem; }
  .text-zone { text-align: center; order: 2; }
  .logo-zone { order: 1; }
  .headline { min-height: 3.6em; }
  .skip-link { display: block; margin: 1rem 0 0; }
}

/* ผู้ใช้ที่ปิดการเคลื่อนไหวในระบบ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}