:root {
  --bg-color: #ffffff; /* White */
  --accent-color: #000000; /* Black */
  --text-color: #000000; /* Black */
  --paper-bg: #fafafa;
  --font-heading: 'Cormorant Garamond', serif;
  --font-body: 'Raleway', sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-body);
  overflow-x: hidden;
  line-height: 1.6;
}

section {
  padding: 100px 20px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

h2.section-title {
  text-align: center;
  font-family: var(--font-heading);
  font-size: 3rem;
  color: var(--accent-color);
  margin-bottom: 60px;
  font-weight: 400;
}

/* Animations */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 1s ease, transform 1s ease;
}
.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* 1. Hero */
.hero {
  height: 1100px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at center, #f0f0f0, #ffffff);
}

.envelope-wrapper {
  position: relative;
  width: 700px;
  height: 440px;
  perspective: 1200px;
  margin: 0 auto;
  cursor: pointer;
  z-index: 10;
}

.instruction {
  position: absolute;
  bottom: -40px;
  left: 0; right: 0;
  text-align: center;
  font-size: 0.9rem;
  letter-spacing: 2px;
  color: var(--accent-color);
  opacity: 0.7;
  transition: opacity 0.5s;
}

.envelope-wrapper:hover .instruction {
  opacity: 1;
}

.envelope {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 1s ease-in-out;
}

/* Envelope base / back */
.envelope::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: #f5f5f5;
  box-shadow: inset 0 0 40px rgba(0,0,0,0.05), 0 20px 40px rgba(0,0,0,0.1);
  border-radius: 2px;
}

/* Flaps using borders */
.flap {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
}

.flap.top {
  top: 0; left: 0;
  border-top: 264px solid var(--paper-bg);
  border-left: 350px solid transparent;
  border-right: 350px solid transparent;
  transform-origin: top;
  transition: transform 1s 0.5s ease;
  z-index: 4;
}

.flap.bottom {
  bottom: 0; left: 0;
  border-bottom: 264px solid #dfd4bf;
  border-left: 350px solid transparent;
  border-right: 350px solid transparent;
  z-index: 3;
}

.flap.left {
  top: 0; left: 0;
  border-left: 350px solid #e8e0cc;
  border-top: 220px solid transparent;
  border-bottom: 220px solid transparent;
  z-index: 2;
}

.flap.right {
  top: 0; right: 0;
  border-right: 350px solid #e8e0cc;
  border-top: 220px solid transparent;
  border-bottom: 220px solid transparent;
  z-index: 2;
}

/* Flap shadows */
.flap.top { filter: drop-shadow(0 5px 5px rgba(0,0,0,0.15)); }
.flap.bottom { filter: drop-shadow(0 -2px 5px rgba(0,0,0,0.1)); }

/* Letter */
.letter {
  position: absolute;
  top: 5px; left: 5px; right: 5px; bottom: 5px;
  background-color: #ffffff;
  z-index: 1; 
  transition: transform 1.5s 1.5s cubic-bezier(0.4, 0, 0.2, 1), z-index 0s 1.5s;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  padding: 20px;
}

.letter-content {
  text-align: center;
  color: #000000;
  border: 1px solid rgba(0, 0, 0, 0.3);
  padding: 40px 20px;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.letter-content h1 {
  font-family: var(--font-heading);
  font-size: 4.4rem;
  margin-bottom: 15px;
  color: #000000;
  font-weight: 500;
}

.letter-content p {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-style: italic;
  color: #4a4a5e;
}

/* Wax Seal */
.wax-seal {
  position: absolute;
  width: 100px;
  height: 100px;
  background: radial-gradient(circle at 30% 30%, #444444, #000000);
  border-radius: 50%;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 5;
  box-shadow: 0 6px 15px rgba(0,0,0,0.4), inset 0 2px 5px rgba(255,255,255,0.3);
  transition: opacity 0.5s 0.5s ease;
  pointer-events: none;
}

.wax-seal::after {
  content: '9Բ';
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  color: #ffffff;
  font-family: var(--font-heading);
  font-size: 1.8rem;
  text-shadow: 0 1px 2px rgba(0,0,0,0.8);
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  width: 70px;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
  text-align: center;
}

/* Envelope Open State */
.envelope.open .flap.top {
  transform: rotateX(180deg);
  z-index: 0;
}
.envelope.open .wax-seal {
  opacity: 0;
}
.envelope.open .letter {
  transform: translateY(-280px) scale(1.1);
  z-index: 10;
  box-shadow: 0 20px 40px rgba(0,0,0,0.5);
}
.envelope.open ~ .instruction {
  opacity: 0;
}

.hero-text-reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 1s 2.5s, transform 1s 2.5s;
  text-align: center;
  margin-top: 80px;
  position: absolute;
  bottom: 10%;
}
.envelope.open ~ .hero-text-reveal {
  opacity: 1;
  transform: translateY(0);
}
.hero-text-reveal h2 {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  color: var(--accent-color);
  font-weight: 300;
}
.hero-text-reveal p {
  font-size: 1rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  margin-top: 10px;
  opacity: 0.8;
}

/* 2. Photo Gallery */
.photo-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  grid-auto-rows: 140px;
  gap: 15px;
  max-width: 1000px;
  margin: 0 auto;
}

/* Precise Collage Layout */
.photo-item:nth-child(1) { grid-column: span 4; grid-row: span 4; } /* Large Featured */
.photo-item:nth-child(2) { grid-column: span 2; grid-row: span 3; } /* Tall */
.photo-item:nth-child(3) { grid-column: span 2; grid-row: span 3; } /* Second Tall / Square */
.photo-item:nth-child(4) { grid-column: span 3; grid-row: span 2; } /* Wide */
.photo-item:nth-child(5) { grid-column: span 1; grid-row: span 2; } /* Small square */

.photo-item {
  position: relative;
  overflow: hidden;
  border-radius: 8px;
  background: #fff;
  padding: 8px; /* Elegant Polaroid-style border */
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
  transition: transform 0.6s cubic-bezier(0.2, 1, 0.3, 1), box-shadow 0.6s ease;
  border: 1px solid rgba(0,0,0,0.05);
}

.photo-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  border-radius: 4px;
  filter: grayscale(100%) contrast(1.1);
  transition: transform 0.8s ease, filter 0.8s ease;
}

.photo-item:hover {
  transform: translateY(-10px) scale(1.02);
  box-shadow: 0 20px 40px rgba(0,0,0,0.15);
  z-index: 5;
}

.photo-item:hover img {
  filter: grayscale(0%) contrast(1);
  transform: scale(1.05);
}

/* 3. Countdown */
.countdown-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 30px;
  flex-wrap: wrap;
}
.countdown-item {
  text-align: center;
  min-width: 100px;
}
.countdown-item span {
  font-family: var(--font-heading);
  font-size: 5rem;
  color: var(--accent-color);
  display: block;
  line-height: 1;
  font-weight: 300;
}
.countdown-item label {
  font-family: var(--font-body);
  font-size: 0.8rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--text-color);
  opacity: 0.7;
  margin-top: 10px;
  display: block;
}
.divider {
  width: 1px;
  height: 80px;
  background-color: var(--accent-color);
  opacity: 0.3;
}

/* 4. About */
.paper-box {
  background-color: #ffffff;
  color: #000000;
  padding: 80px 60px;
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  border-radius: 2px;
  position: relative;
}
.paper-box::after {
  content: '';
  position: absolute;
  top: 10px; left: 10px; right: 10px; bottom: 10px;
  border: 1px solid rgba(0, 0, 0, 0.4);
  pointer-events: none;
}
.paper-box h2 {
  font-family: var(--font-heading);
  font-size: 3rem;
  color: #000000;
  margin-bottom: 30px;
  font-weight: 500;
}
.paper-box p {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  line-height: 1.8;
  font-style: italic;
  color: #333344;
}

/* 5. Video - Removed */

/* 6. Classmates */
.teacher-mention {
  text-align: center;
  margin-bottom: 60px;
}

.teacher-mention .img-wrapper {
  width: 200px;
  height: 200px;
  margin: 0 auto 15px;
  border-radius: 50%;
  border: 1px solid rgba(0, 0, 0, 0.3);
  overflow: hidden;
  background: var(--paper-bg);
}

.teacher-mention .img-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(100%);
  transition: filter 0.6s ease, transform 0.6s ease;
  display: block;
}

.teacher-mention:hover .img-wrapper img {
  filter: grayscale(0%);
  transform: scale(1.05);
}

.teacher-mention .teacher-name {
  display: block;
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-style: italic;
  color: var(--text-color);
}

.classmates-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px;
  max-width: 900px;
  margin: 0 auto;
}
.classmate-item {
  text-align: center;
}
.classmate-item .img-wrapper {
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.3);
  border-radius: 4px;
  margin-bottom: 20px;
}
.classmate-item img {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  filter: grayscale(100%);
  transition: transform 0.6s ease;
  display: block;
}
.classmate-item:hover img {
  transform: scale(1.05);
}
.classmate-item .name {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  color: var(--text-color);
  letter-spacing: 1px;
}

/* 7. Calendar */
.calendar-wrapper {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
  background: rgba(0,0,0,0.02);
  padding: 50px;
  border: 1px solid rgba(0, 0, 0, 0.2);
  border-radius: 4px;
}
.calendar-wrapper h3 {
  font-family: var(--font-heading);
  font-size: 3rem;
  color: var(--accent-color);
  margin-bottom: 40px;
  font-weight: 300;
}
.calendar-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 15px;
  margin-bottom: 40px;
}
.day-name {
  font-family: var(--font-body);
  color: var(--accent-color);
  font-weight: 500;
  font-size: 0.9rem;
  letter-spacing: 1px;
  margin-bottom: 10px;
}
.day {
  font-family: var(--font-body);
  font-size: 1.1rem;
  display: flex;
  justify-content: center;
  align-items: center;
  aspect-ratio: 1;
  border-radius: 50%;
  transition: background 0.3s;
}
.day.disabled {
  opacity: 0.2;
}
.day.highlight {
  border: 1px solid var(--accent-color);
  color: var(--bg-color);
  background-color: var(--accent-color);
}
.event-time {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  color: var(--text-color);
  font-style: italic;
}

/* 8. CTA */
.cta-section {
  text-align: center;
  padding: 120px 20px;
}
.gold-btn {
  background: transparent;
  border: 1px solid var(--accent-color);
  color: var(--accent-color);
  padding: 18px 50px;
  font-family: var(--font-body);
  font-size: 1.1rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.4s ease;
  margin-top: 20px;
}
.gold-btn:hover {
  background: var(--accent-color);
  color: var(--bg-color);
}

footer {
  text-align: center;
  padding: 40px 20px;
  font-size: 0.9rem;
  color: rgba(0, 0, 0, 0.5);
  border-top: 1px solid rgba(0,0,0,0.1);
}

/* Responsive */
@media (max-width: 768px) {
  .envelope-wrapper {
    transform: scale(0.6);
    transform-origin: center center;
    margin: -88px -140px;
  }
  .hero { height: 900px; }
  .letter-content h1 { font-size: 3.2rem; }
  .letter-content p { font-size: 1.8rem; }
  .envelope.open .letter { transform: translateY(-220px) scale(1.05); }
  .hero-text-reveal h2 { font-size: 2rem; }
  .hero-text-reveal p { font-size: 0.85rem; }
  .countdown-container { flex-direction: column; gap: 15px; }
  .divider { width: 60px; height: 1px; }
  .classmates-grid { grid-template-columns: 1fr; }
  .paper-box { padding: 40px 20px; }
  .paper-box h2 { font-size: 2rem; }
  h2.section-title { font-size: 2.2rem; }
  .calendar-wrapper { padding: 25px 15px; }
  .calendar-grid { gap: 5px; }
  
  /* Collage Mobile Fix */
  .photo-grid {
    grid-template-columns: repeat(2, 1fr);
    grid-auto-rows: 180px;
    gap: 10px;
  }
  .photo-item:nth-child(1) { grid-column: span 2; grid-row: span 2; }
  .photo-item:nth-child(2) { grid-column: span 1; grid-row: span 2; }
  .photo-item:nth-child(3) { grid-column: span 1; grid-row: span 2; }
  .photo-item:nth-child(4) { grid-column: span 1; grid-row: span 1; }
  .photo-item:nth-child(5) { grid-column: span 1; grid-row: span 1; }
}

@media (max-width: 480px) {
  .envelope-wrapper {
    transform: scale(0.45);
    transform-origin: center center;
    margin: -121px -192px;
  }
  .hero { height: 800px; }
  .letter-content h1 { font-size: 2.8rem; }
  .letter-content p { font-size: 1.5rem; }
  .envelope.open .letter { transform: translateY(-200px) scale(1); }
  .hero-text-reveal { bottom: 8%; width: 90%; left: 50%; transform: translateX(-50%); }
  .hero-text-reveal h2 { font-size: 1.6rem; }
  .hero-text-reveal p { font-size: 0.75rem; }
}