/* ==========================================================================
   Design System & Variable Declarations
   ========================================================================== */
:root {
  /* Color Palette (Aura Pastel) */
  --primary-color: #f7b4c4; /* Pastel Cherry Blossom Pink */
  --primary-light: #fce1e6;
  --primary-dark: #e096a7;
  --secondary-color: #ffd1b3; /* Peach orange */
  --accent-color: #e5c3ff; /* Lavender */
  --cream-white: #fffbfc;
  --glass-bg: rgba(255, 255, 255, 0.45);
  --glass-border: rgba(255, 255, 255, 0.6);
  --glass-shadow: rgba(224, 150, 167, 0.15);
  --text-main: #5c4a4e;
  --text-muted: #8c767b;
  --wax-seal-color: #e0728c;
  
  /* Fonts */
  --font-serif: "Playfair Display", Georgia, serif;
  --font-sans: "Plus Jakarta Sans", system-ui, -apple-system, sans-serif;
  
  /* Transitions */
  --transition-smooth: all 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-fast: all 0.3s ease;
}

/* ==========================================================================
   Reset & Core Styling
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: #fceef0;
  min-height: 100vh;
  min-height: -webkit-fill-available;
  overflow-x: hidden;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Aura Ambient Glow Backgrounds */
.glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  z-index: 0;
  opacity: 0.6;
  pointer-events: none;
}

.orb-1 {
  width: 45vw;
  height: 45vw;
  background: radial-gradient(circle, var(--primary-light) 0%, var(--secondary-color) 100%);
  top: -10%;
  left: -10%;
  animation: floatOrb 25s infinite alternate ease-in-out;
}

.orb-2 {
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, var(--accent-color) 0%, var(--primary-light) 100%);
  bottom: -15%;
  right: -10%;
  animation: floatOrb 30s infinite alternate-reverse ease-in-out;
}

@keyframes floatOrb {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(5%, 8%) scale(1.1); }
  100% { transform: translate(-3%, -5%) scale(0.9); }
}

/* ==========================================================================
   Sparkles (Dynamic Particles)
   ========================================================================== */
.sparkles-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1;
  overflow: hidden;
}

.sparkle {
  position: absolute;
  background: radial-gradient(circle, #fff 10%, rgba(255,255,255,0) 80%);
  border-radius: 50%;
  opacity: 0;
  animation: twinkle var(--duration, 4s) infinite ease-in-out;
}

@keyframes twinkle {
  0%, 100% { opacity: 0; transform: translateY(0) scale(0.5); }
  50% { opacity: 0.8; transform: translateY(-50px) scale(1.2); }
}

/* ==========================================================================
   Layout Containers
   ========================================================================== */
.app-container {
  width: 100%;
  max-width: 480px;
  min-height: 100vh;
  padding: 2.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 2;
}

/* Header Styles */
.app-header {
  text-align: center;
  margin-bottom: 2rem;
  animation: fadeInDown 1s ease;
}

.app-title {
  font-family: var(--font-serif);
  font-size: 2.75rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.5px;
  text-shadow: 0 2px 10px rgba(224, 150, 167, 0.15);
  margin-bottom: 0.5rem;
}

.app-subtitle {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 400;
  letter-spacing: 0.5px;
}

/* Main Area */
.main-content {
  flex-grow: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  perspective: 1000px;
}

/* ==========================================================================
   Envelope & Letter Interactive Animation
   ========================================================================== */
.envelope-wrapper {
  position: relative;
  width: 320px;
  height: 220px;
  margin-top: 3rem;
  margin-bottom: 5rem;
}

/* Base Envelope */
.envelope {
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: #fad1d8;
  border-radius: 8px;
  box-shadow: 0 15px 35px rgba(224, 150, 167, 0.35);
  cursor: pointer;
  z-index: 4;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  transform-style: preserve-3d;
}

.envelope:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 45px rgba(224, 150, 167, 0.45);
}

.envelope:active {
  transform: translateY(0);
}

/* Flaps and Pocket Design */
.flap {
  position: absolute;
  width: 0;
  height: 0;
  border-style: solid;
}

.top-flap {
  border-width: 110px 160px 0 160px;
  border-color: #fabcc8 transparent transparent transparent;
  top: 0;
  left: 0;
  transform-origin: top;
  z-index: 6;
  transition: transform 0.4s ease 0.2s, z-index 0.2s ease 0.4s;
}

.left-flap {
  border-width: 110px 0 110px 160px;
  border-color: transparent transparent transparent #f7b4c4;
  top: 0;
  left: 0;
  z-index: 5;
  border-radius: 8px 0 0 8px;
}

.right-flap {
  border-width: 110px 160px 110px 0;
  border-color: transparent #f7b4c4 transparent transparent;
  top: 0;
  right: 0;
  z-index: 5;
  border-radius: 0 8px 8px 0;
}

.pocket {
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: transparent;
  border-bottom: 220px solid #f9aab9;
  border-left: 160px solid transparent;
  border-right: 160px solid transparent;
  top: 0;
  left: 0;
  z-index: 4;
  border-radius: 8px;
}

/* Wax Seal */
.wax-seal {
  position: absolute;
  width: 50px;
  height: 50px;
  background: radial-gradient(circle, var(--wax-seal-color) 60%, #b84962 100%);
  border-radius: 50%;
  top: calc(50% - 15px);
  left: calc(50% - 25px);
  z-index: 7;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
  cursor: pointer;
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  transform-origin: center;
}

.envelope:hover .wax-seal {
  transform: scale(1.1) rotate(5deg);
}

.click-prompt {
  position: absolute;
  bottom: -35px;
  width: 100%;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 1px;
  opacity: 0.8;
  animation: heartBeat 2s infinite ease-in-out;
}

/* The Letter Card inside the Envelope */
.letter-card {
  position: absolute;
  width: 290px;
  height: 380px;
  background-color: var(--cream-white);
  border-radius: 12px;
  padding: 2.5rem 1.75rem 2rem 1.75rem;
  box-shadow: 0 10px 30px rgba(224, 150, 167, 0.1);
  left: 15px;
  top: 10px;
  z-index: 3;
  opacity: 0;
  transform: translateY(0) scale(0.9);
  pointer-events: none;
  transition: transform 0.6s cubic-bezier(0.25, 1, 0.5, 1), opacity 0.6s cubic-bezier(0.25, 1, 0.5, 1), box-shadow 0.6s ease;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 1px solid rgba(247, 180, 196, 0.3);
}

.letter-pattern {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 12px;
  border: 2px solid rgba(247, 180, 196, 0.15);
  margin: 0;
  pointer-events: none;
}

.letter-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px dashed rgba(247, 180, 196, 0.4);
  padding-bottom: 0.75rem;
}

.letter-date {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary-dark);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.letter-sparkle {
  color: var(--secondary-color);
  font-size: 1.1rem;
}

.letter-body {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 1.5rem 0;
}

.quote-text {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  line-height: 1.7;
  color: var(--text-main);
  font-style: italic;
  font-weight: 500;
}

.quote-author {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 1.25rem;
  letter-spacing: 0.5px;
}

/* Actions inside card */
.letter-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.5s ease 0.5s;
}

.action-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.6rem 1.2rem;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition-fast);
  box-shadow: 0 4px 10px var(--glass-shadow);
}

.action-btn svg {
  stroke: var(--primary-dark);
}

.action-btn:hover {
  background: var(--primary-light);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

.action-btn:active {
  transform: translateY(0);
}

/* ==========================================================================
   Envelope Open State Rules
   ========================================================================== */
.envelope-wrapper.open .top-flap {
  transform: rotateX(180deg);
  z-index: 2;
  transition: transform 0.4s ease, z-index 0.2s ease 0.1s;
}

.envelope-wrapper.open .wax-seal {
  transform: scale(0) rotate(-45deg);
  opacity: 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
  pointer-events: none;
}

.envelope-wrapper.open .click-prompt {
  display: none;
}

.envelope-wrapper.open .letter-card {
  transform: translateY(-220px) scale(1);
  opacity: 1;
  pointer-events: auto;
  z-index: 5;
  box-shadow: 0 20px 45px rgba(224, 150, 167, 0.2);
}

.envelope-wrapper.open .letter-actions {
  opacity: 1;
}

.envelope-wrapper.open .envelope {
  box-shadow: 0 5px 15px rgba(224, 150, 167, 0.15);
  pointer-events: none; /* Block clicking envelope when opened */
}

/* ==========================================================================
   Controls & Panels (History)
   ========================================================================== */
.bottom-controls {
  margin-top: 1.5rem;
  animation: fadeInUp 1s ease;
}

.control-btn {
  background: var(--glass-bg);
  border: 1px solid var(--glass-border);
  padding: 0.75rem 1.5rem;
  border-radius: 25px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition-fast);
  box-shadow: 0 4px 15px var(--glass-shadow);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.control-btn svg {
  stroke: var(--primary-dark);
}

.control-btn:hover {
  background: var(--cream-white);
  border-color: var(--primary-color);
  box-shadow: 0 6px 20px rgba(224, 150, 167, 0.25);
  transform: translateY(-2px);
}

/* History Slider Over Panel */
.history-panel {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 10;
  visibility: hidden;
  transition: visibility 0.4s;
}

.history-panel.show {
  visibility: visible;
}

.history-backdrop {
  position: absolute;
  width: 100%;
  height: 100%;
  background: rgba(92, 74, 78, 0.3);
  backdrop-filter: blur(4px);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.history-panel.show .history-backdrop {
  opacity: 1;
}

.history-content {
  position: absolute;
  right: 0;
  top: 0;
  width: 100%;
  max-width: 400px;
  height: 100%;
  background: rgba(255, 251, 252, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-left: 1px solid var(--glass-border);
  padding: 2.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: -10px 0 30px rgba(92, 74, 78, 0.05);
}

.history-panel.show .history-content {
  transform: translateX(0);
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
}

.history-header h2 {
  font-family: var(--font-serif);
  font-size: 1.75rem;
  color: var(--text-main);
}

.close-history-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.3s;
}

.close-history-btn:hover {
  color: var(--primary-dark);
}

.history-list {
  flex-grow: 1;
  overflow-y: auto;
  padding-right: 0.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* History Card */
.history-item {
  background: var(--cream-white);
  border: 1px solid rgba(247, 180, 196, 0.2);
  border-radius: 12px;
  padding: 1.25rem;
  box-shadow: 0 4px 15px rgba(224, 150, 167, 0.05);
  animation: slideInLeft 0.4s ease forwards;
  position: relative;
}

.history-item-date {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
  display: block;
}

.history-item-text {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text-main);
  font-style: italic;
}

.empty-history {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  height: 60%;
  color: var(--text-muted);
  padding: 0 1rem;
}

.empty-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  animation: pulse 2s infinite ease-in-out;
}

/* ==========================================================================
   Toast Notification System
   ========================================================================== */
.toast {
  position: fixed;
  bottom: 30px;
  background: rgba(92, 74, 78, 0.85);
  color: #fff;
  padding: 0.75rem 1.5rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
  backdrop-filter: blur(5px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.3s, transform 0.3s;
  z-index: 100;
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Footer Styles
   ========================================================================== */
.app-footer {
  margin-top: 2rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  opacity: 0.7;
}

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes heartBeat {
  0% { transform: scale(1); }
  14% { transform: scale(1.05); }
  28% { transform: scale(1); }
  42% { transform: scale(1.05); }
  70% { transform: scale(1); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-15px); }
  to { opacity: 1; transform: translateX(0); }
}

/* Mobile Optimizations */
@media (max-width: 360px) {
  .envelope-wrapper {
    width: 290px;
    height: 200px;
  }
  .top-flap {
    border-width: 100px 145px 0 145px;
  }
  .left-flap {
    border-width: 100px 0 100px 145px;
  }
  .right-flap {
    border-width: 100px 145px 100px 0;
  }
  .pocket {
    border-bottom-width: 200px;
    border-left-width: 145px;
    border-right-width: 145px;
  }
  .letter-card {
    width: 260px;
    height: 350px;
  }
  .envelope-wrapper.open .letter-card {
    transform: translateY(-200px);
  }
}

/* ==========================================================================
   Journal Modal Styles
   ========================================================================== */
.journal-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 20;
  display: flex;
  justify-content: center;
  align-items: center;
  visibility: hidden;
  transition: visibility 0.4s;
}

.journal-modal.show {
  visibility: visible;
}

.journal-modal-backdrop {
  position: absolute;
  width: 100%;
  height: 100%;
  background: rgba(92, 74, 78, 0.4);
  backdrop-filter: blur(5px);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.journal-modal.show .journal-modal-backdrop {
  opacity: 1;
}

.journal-modal-content {
  position: relative;
  width: 90%;
  max-width: 380px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: 16px;
  padding: 2rem 1.5rem;
  box-shadow: 0 20px 50px rgba(92, 74, 78, 0.15);
  transform: scale(0.9);
  opacity: 0;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.4s ease;
  z-index: 2;
}

.journal-modal.show .journal-modal-content {
  transform: scale(1);
  opacity: 1;
}

.journal-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
}

.journal-modal-header h2 {
  font-family: var(--font-serif);
  font-size: 1.5rem;
  color: var(--text-main);
}

.close-journal-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.3s;
}

.close-journal-btn:hover {
  color: var(--primary-dark);
}

.journal-modal-body {
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
}

.journal-quote-preview {
  background: var(--primary-light);
  border-left: 3px solid var(--primary-color);
  padding: 0.75rem 1rem;
  border-radius: 4px 8px 8px 4px;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.9rem;
  color: var(--text-main);
  margin-bottom: 1.25rem;
  line-height: 1.4;
}

.journal-input-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.journal-note-input {
  width: 100%;
  height: 100px;
  background: rgba(255, 255, 255, 0.5);
  border: 1px solid rgba(247, 180, 196, 0.4);
  border-radius: 10px;
  padding: 0.75rem;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--text-main);
  resize: none;
  outline: none;
  transition: var(--transition-fast);
}

.journal-note-input:focus {
  border-color: var(--primary-color);
  background: #fff;
  box-shadow: 0 0 10px rgba(247, 180, 196, 0.25);
}

.journal-char-count {
  text-align: right;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.journal-modal-footer {
  display: flex;
  justify-content: flex-end;
}

.modal-btn {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
  border: none;
  color: white;
  padding: 0.75rem 1.75rem;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(224, 150, 167, 0.3);
  transition: var(--transition-fast);
}

.modal-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(224, 150, 167, 0.45);
}

.modal-btn:active {
  transform: translateY(0);
}

/* History note rendering */
.history-item-note {
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px dashed rgba(247, 180, 196, 0.3);
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  line-height: 1.4;
}

.history-item-note::before {
  content: "✍️";
  font-size: 0.9rem;
}

/* ==========================================================================
   Birthday Confetti
   ========================================================================== */
.confetti-particle {
  position: absolute;
  opacity: 0.8;
  pointer-events: none;
  animation: fall var(--fall-duration) linear var(--fall-delay) forwards;
  z-index: 10;
}

@keyframes fall {
  0% {
    transform: translateY(-20px) rotate(0deg) translateX(0);
    opacity: 0.8;
  }
  50% {
    opacity: 1;
  }
  100% {
    transform: translateY(105vh) rotate(360deg) translateX(var(--sway-amount));
    opacity: 0;
  }
}