/* Core Theme */
:root {
  --bg-center: #1e5a8f; /* lighter blue center */
  --bg-edge: #0a2847; /* dark navy blue edges */
  --text: #ffffff;
  --text-secondary: rgba(255,255,255,0.9);
  --accent: #4a8fd6;
  --accent-strong: #6ba6e3;
  --chip-bg: rgba(255,255,255,0.06);
  --chip-bg-active: rgba(127, 184, 255, 0.18);
  --shadow: 0 4px 12px rgba(0,0,0,0.5);
  /* Layout scaling - base responsive values */
  --content-width: min(480px, 92vw);
  --gap: clamp(14px, 2vh, 24px);
  --gos-logo-size: clamp(140px, 22vw, 220px);
  --saudi-logo-size: clamp(140px, 22vw, 220px);
  --bayer-logo-size: clamp(120px, 18vw, 180px);
  --text-small: clamp(12px, 1.8vw, 15px);
  --text-medium: clamp(13px, 2vw, 16px);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--text);
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(ellipse at center, var(--bg-center) 0%, var(--bg-edge) 70%);
  overflow: hidden;
}

.app {
  position: relative;
  min-height: 100vh;
  display: grid;
  place-items: center;
}

/* Page containers */
.page {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--gap);
  padding: clamp(32px, 5vh, 56px) clamp(20px, 4vw, 32px);
  max-width: var(--content-width);
  width: 100%;
  margin: 0 auto;
  transition: opacity .45s ease, transform .45s ease;
  opacity: 0;
  transform: translateY(18px) scale(.98);
  pointer-events: none;
  overflow: visible;
}
.page.active {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.title { 
  font: italic 700 clamp(56px, 11vw, 80px)/0.95 Barlow, Inter, sans-serif; 
  letter-spacing: 2px; 
  margin: clamp(8px, 1.5vh, 14px) 0; 
  text-transform: uppercase;
  transform: rotate(-3deg);
  text-shadow: 0 4px 12px rgba(0,0,0,0.6);
}
.subtitle { font: italic 600 28px/1.25 Barlow, Inter, sans-serif; text-align: center; max-width: 34ch; font-size: clamp(26px, 3.8vw, 42px); }
.italic { font-style: italic; }

/* Gulf logo */
.gos-logo {
  width: var(--gos-logo-size);
  max-width: 88vw;
  height: auto;
  display: block;
  filter: drop-shadow(0 4px 12px rgba(0,0,0,0.5));
  margin-bottom: clamp(6px, 1vh, 10px);
}

/* Saudi logo */
.saudi-logo {
  width: var(--saudi-logo-size);
  max-width: 88vw;
  height: auto;
  display: block;
  filter: drop-shadow(0 4px 12px rgba(0,0,0,0.5));
  margin-top: clamp(6px, 1vh, 10px);
  margin-bottom: clamp(6px, 1vh, 10px);
}

/* Sponsor Section */
.sponsor-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(12px, 1.8vh, 18px);
  margin-top: clamp(10px, 2vh, 16px);
  margin-bottom: clamp(8px, 1.5vh, 12px);
}
.sponsor-text {
  margin: 0;
  font-size: clamp(15px, 2.4vw, 19px);
  color: var(--text-secondary);
  text-align: center;
  font-weight: 400;
  letter-spacing: 0.5px;
}
.bayer-logo {
  width: var(--bayer-logo-size);
  max-width: 88vw;
  height: auto;
  display: block;
  filter: drop-shadow(0 4px 12px rgba(0,0,0,0.5));
}
.logo { width: 160px; height: 70px; border: 2px solid var(--accent); border-radius: 12px; box-shadow: var(--shadow); opacity: .95; display: grid; place-items: center; overflow: hidden; }
.logo-center { width: clamp(280px, 36vw, 600px); height: auto; aspect-ratio: 5 / 3; border-radius: 16px; display: grid; place-items: center; overflow: hidden; }
/* Images inside rectangular logo frames */
.logo img, .logo-center img { max-width: 90%; max-height: 90%; width: auto; height: auto; object-fit: contain; display: block; }
.done-img { width: clamp(280px, 36vw, 600px); height: auto; display: block; }

/* Inputs and buttons */
.input {
  width: 100%;
  max-width: 460px;
  padding: 14px 18px;
  color: var(--text);
  background: rgba(255,255,255,0.06);
  border: 2px solid var(--accent);
  border-radius: 12px;
  outline: none;
  font-size: 18px;
}
.input::placeholder { color: var(--muted); font-style: italic; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: clamp(14px, 2.2vw, 18px) clamp(60px, 12vw, 100px);
  color: var(--text);
  background: rgba(74,143,214,0.25);
  border: 2px solid rgba(74,143,214,0.6);
  border-radius: clamp(12px, 2vw, 16px);
  cursor: pointer;
  transition: transform .2s ease, background .25s ease, box-shadow .25s ease, border-color .25s ease;
  box-shadow: 0 4px 16px rgba(0,0,0,0.5);
  font-style: italic;
  font-size: clamp(28px, 5vw, 36px);
  font-weight: 600;
  letter-spacing: 1px;
  margin-top: clamp(16px, 3vh, 24px);
}
.btn.primary { 
  background: rgba(74,143,214,0.25); 
  border-color: rgba(74,143,214,0.6);
}
.btn:hover { 
  transform: translateY(-2px); 
  background: rgba(107,166,227,0.35); 
  box-shadow: 0 6px 20px rgba(0,0,0,0.6);
  border-color: var(--accent-strong);
}
.btn:active { transform: translateY(-1px); }
.btn[disabled] { opacity: .6; cursor: not-allowed; }

/* Chips (hashtag buttons) */
.hashtags { display: grid; gap: 18px; width: 100%; max-width: 460px; }
.chip {
  width: 100%;
  padding: 14px 18px; font-size: 22px; color: var(--text);
  border: 2px solid var(--accent); background: var(--chip-bg);
  border-radius: 12px; cursor: pointer; text-align: left;
  transition: background .2s ease, border-color .2s ease, transform .12s ease;
}
.chip:hover { background: rgba(127,184,255,0.16); transform: translateY(-1px); }
.chip[aria-pressed="true"] { background: var(--chip-bg-active); border-color: var(--accent-strong); }

.form-group { width: 100%; max-width: 460px; }

.errors { min-height: 26px; width: 100%; max-width: 460px; }
.error { color: #ffd2d2; margin: 4px 2px; font-size: 14px; }

.center-logo { display: grid; place-items: center; margin: 6px 0 6px; }
.thankyou { font-size: 28px; text-align: center; margin: 6px 0 10px; }

/* Mobile phones (portrait) */
@media (max-width: 480px) {
  :root { 
    --content-width: 94vw; 
    --gap: 16px; 
    --gos-logo-size: 160px; 
    --saudi-logo-size: 160px; 
    --bayer-logo-size: 130px;
    --text-small: 13px;
    --text-medium: 14px; 
  }
  .page { padding: clamp(36px, 6vh, 48px) 20px; }
  .title { font-size: clamp(60px, 14vw, 74px); }
  .subtitle { font-size: 28px; }
  .btn { font-size: 30px; padding: 16px 70px; border-width: 2px; }
  .chip { font-size: 20px; padding: 16px 18px; }
  .input { font-size: 18px; padding: 16px 18px; }
  .thankyou { font-size: 26px; }
  .logo-center { width: 85vw; }
  .done-img { width: 85vw; }
}

/* Tablet (portrait) and larger phones */
@media (min-width: 481px) and (max-width: 768px) {
  :root { 
    --content-width: 88vw; 
    --gap: 18px; 
    --gos-logo-size: 190px; 
    --saudi-logo-size: 190px; 
    --bayer-logo-size: 150px;
    --text-small: 14px;
    --text-medium: 15px; 
  }
  .page { padding: clamp(40px, 6vh, 60px) 24px; }
  .title { font-size: clamp(68px, 12vw, 82px); }
  .subtitle { font-size: 26px; }
  .btn { font-size: 32px; padding: 17px 80px; border-width: 2px; }
  .chip { font-size: 20px; padding: 15px; }
  .input { font-size: 18px; padding: 15px 18px; }
  .thankyou { font-size: 24px; }
  .logo-center { width: 70vw; max-width: 500px; }
  .done-img { width: 70vw; max-width: 500px; }
}

/* Tablet (landscape) and small laptops */
@media (min-width: 769px) and (max-width: 1023px) {
  :root { 
    --content-width: 520px; 
    --gap: 20px; 
    --gos-logo-size: 200px; 
    --saudi-logo-size: 200px; 
    --bayer-logo-size: 160px;
    --text-small: 14px;
    --text-medium: 15px; 
  }
  .page { padding: clamp(48px, 7vh, 68px) 28px; }
  .title { font-size: 76px; }
  .subtitle { font-size: 27px; }
  .btn { font-size: 34px; padding: 18px 85px; border-width: 2px; }
  .chip { font-size: 21px; padding: 15px; }
  .input { font-size: 18px; padding: 15px 18px; }
  .thankyou { font-size: 26px; }
  .logo-center { width: 60vw; max-width: 550px; }
  .done-img { width: 60vw; max-width: 550px; }
}

/* Desktop and larger screens */
@media (min-width: 1024px) {
  :root { 
    --content-width: 540px; 
    --gap: 22px; 
    --gos-logo-size: 210px; 
    --saudi-logo-size: 210px; 
    --bayer-logo-size: 170px;
    --text-small: 15px;
    --text-medium: 16px; 
  }
  .page { padding: clamp(52px, 7vh, 72px) 32px; }
  .title { font-size: 78px; }
  .subtitle { font-size: 26px; }
  .btn { font-size: 35px; padding: 18px 90px; border-width: 2px; }
  .chip { font-size: 20px; padding: 15px; }
  .input { font-size: 18px; padding: 15px 18px; }
  .thankyou { font-size: 26px; }
  .logo-center { width: 45vw; max-width: 450px; }
  .done-img { width: 45vw; max-width: 450px; }
}

/* Large desktop and ultrawide */
@media (min-width: 1440px) {
  :root { 
    --content-width: 580px; 
    --gos-logo-size: 220px; 
    --saudi-logo-size: 220px; 
    --bayer-logo-size: 180px;
    --text-small: 15px;
    --text-medium: 16px; 
  }
  .title { font-size: 80px; }
  .btn { font-size: 36px; padding: 18px 95px; }
  .logo-center { width: 42vw; max-width: 480px; }
  .done-img { width: 42vw; max-width: 480px; }
}

/* Accessibility */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* Hide broken/empty placeholders until src is provided */
img[src=""], img:not([src]) { display: none; }