/* ==========================================================================
   DESIGN TOKENS - BẢNG MÀU & THIẾT KẾ THỦ CÔNG ẤM ÁP, SANG TRỌNG
   Phong cách: Món quà riêng cho gia đình, trang nhã, ấm áp, tinh tế
   ========================================================================== */
:root {
  /* Bảng màu chủ đạo: Tông màu ấm áp, tình cảm của giấy thủ công & mực ấm */
  --bg-base: #faf6f0;               /* Nền kem ấm dịu mắt */
  --card-bg: #ffffff;                /* Trắng ngọc trai mềm mại */
  --card-bg-subtle: #fdfbf7;         /* Nền thẻ phụ ngả kem */
  --card-border: #eadccf;            /* Viền thẻ màu be nhạt trang nhã */
  --card-border-gold: rgba(194, 146, 85, 0.35); /* Viền chỉ vàng ánh kim */
  
  /* Màu mực chữ (Độ tương phản cao, dễ đọc cho Ba Mẹ) */
  --text-ink: #2c2422;               /* Chữ chính màu cà phê trầm ấm */
  --text-body: #4a3e3b;              /* Chữ nội dung mềm mại */
  --text-muted: #7d706a;             /* Chữ phụ, ghi chú */
  
  /* Điểm nhấn cảm xúc */
  --accent-warm: #ba4732;            /* Đỏ cam đất ấm áp, không lòe loẹt */
  --accent-warm-hover: #9e3724;      /* Đỏ cam đậm khi hover */
  --accent-blush: #f7ebe1;           /* Nền hồng phấn dịu ngọt */
  --accent-gold: #c29255;            /* Vàng đồng cổ điển quý phái */
  --accent-gold-light: #faecd5;      /* Vàng kem nhạt */
  
  /* Typography */
  --font-main: 'Be Vietnam Pro', sans-serif;
  --font-heading: 'Playfair Display', serif;

  /* Bo góc & Đổ bóng nhiều lớp (Layered Shadows) */
  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 26px;
  --radius-xl: 32px;
  --shadow-soft: 0 4px 16px rgba(50, 35, 25, 0.05);
  --shadow-card: 0 16px 40px rgba(50, 35, 25, 0.07), 0 2px 8px rgba(50, 35, 25, 0.03);
  --shadow-hover: 0 20px 48px rgba(50, 35, 25, 0.12), 0 4px 14px rgba(50, 35, 25, 0.05);
  --shadow-glow: 0 0 24px rgba(186, 71, 50, 0.2);

  /* Chuyển động mượt mà */
  --ease-smooth: cubic-bezier(0.25, 1, 0.5, 1);
  --transition-normal: 0.35s var(--ease-smooth);
}

/* ==========================================================================
   RESET & BẦU KHÔNG KHÍ NỀN (ATMOSPHERE)
   ========================================================================== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-base);
  /* Ánh sáng ấm áp lan tỏa như nắng sớm rọi lên trang giấy thư */
  background-image: 
    radial-gradient(circle at 10% 8%, rgba(247, 235, 225, 0.8) 0%, transparent 45%),
    radial-gradient(circle at 90% 75%, rgba(250, 236, 213, 0.5) 0%, transparent 50%),
    radial-gradient(circle at 50% 40%, rgba(255, 255, 255, 0.6) 0%, transparent 70%);
  background-attachment: fixed;
  color: var(--text-ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* Khung chứa trung tâm, căn lề mobile-first, giống bức thiệp đặt ở giữa */
.container {
  width: 100%;
  max-width: 660px;
  margin: 0 auto;
  padding: 1.8rem 1.25rem 3.5rem;
}

/* ==========================================================================
   TRÌNH PHÁT NHẠC NỀN TỐI GIẢN (MINIMALIST MUSIC PLAYER)
   ========================================================================== */
.music-player-container {
  position: fixed;
  top: 1.2rem;
  right: 1.2rem;
  z-index: 1000;
  max-width: calc(100vw - 2.4rem);
}

.music-player {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--card-border);
  padding: 0.35rem 0.45rem 0.35rem 0.85rem;
  border-radius: 999px;
  box-shadow: 0 4px 16px rgba(50, 35, 25, 0.08);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.music-player:hover {
  background: #ffffff;
  box-shadow: 0 6px 20px rgba(50, 35, 25, 0.12);
  border-color: rgba(194, 146, 85, 0.5);
}

/* Nút chính Bật / Tạm dừng */
.music-btn {
  background: none;
  border: none;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-main);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-ink);
  cursor: pointer;
  padding: 0.2rem 0.2rem;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: color 0.2s ease;
}

.music-icon {
  font-size: 1rem;
  display: inline-block;
  transition: transform 0.3s ease;
}

/* Trạng thái đang phát nhạc */
.music-player.playing {
  border-color: rgba(186, 71, 50, 0.38);
  background: rgba(255, 255, 255, 0.98);
  box-shadow: 0 4px 18px rgba(186, 71, 50, 0.16);
}

.music-player.playing .music-text {
  color: var(--accent-warm);
  font-weight: 600;
}

.music-player.playing .music-icon {
  animation: musicPulse 1.6s ease-in-out infinite;
}

@keyframes musicPulse {
  0%, 100% { transform: scale(1) rotate(0deg); }
  25% { transform: scale(1.18) rotate(-8deg); }
  75% { transform: scale(1.18) rotate(8deg); }
}

/* Nút phụ Tắt / Bật tiếng (Mute / Unmute) */
.mute-btn {
  background: var(--accent-blush);
  border: 1px solid rgba(194, 146, 85, 0.3);
  border-radius: 50%;
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 0.82rem;
  color: var(--text-muted);
  transition: transform 0.2s ease, background-color 0.2s ease;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

.mute-btn:hover {
  background: #fce8db;
  transform: scale(1.08);
}

.mute-btn:active {
  transform: scale(0.92);
}

.mute-btn.muted {
  background: #f1eae2;
  border-color: #d6c8bc;
}

/* ==========================================================================
   CANVAS HIỆU ỨNG CONFETTI (PHÁO GIẤY)
   ========================================================================== */
.confetti-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 998;
}

/* ==========================================================================
   MÀN HÌNH ĐẦU TIÊN: 🎁 MỞ QUÀ (HERO / GIFT SCREEN)
   ========================================================================== */
.hero-screen {
  min-height: 84vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2.2rem 0 1.2rem;
}

.hero-content {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Tiêu đề phụ: Trang nhã, ánh kim đồng */
.greeting-subtitle {
  font-size: 0.88rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent-gold);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

/* Tiêu đề chính */
.main-title {
  font-family: var(--font-heading);
  font-size: 2.3rem;
  font-weight: 700;
  color: var(--text-ink);
  margin-bottom: 0.75rem;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

/* Dòng chữ: "Một món quà nhỏ dành cho Ba và Mẹ ❤️" */
.gift-message {
  font-size: 1.12rem;
  font-weight: 500;
  font-style: italic;
  color: var(--accent-warm);
  margin-bottom: 2rem;
  max-width: 90%;
  line-height: 1.6;
}

/* ==========================================================================
   THIẾT KẾ HỘP QUÀ TINH TẾ (CSS LUXURY GIFT BOX)
   ========================================================================== */
.gift-container {
  margin: 0.5rem auto 2.2rem;
  position: relative;
  /* Hiệu ứng thở nhẹ nhàng, êm dịu */
  animation: floatBreathing 3.8s ease-in-out infinite;
}

@keyframes floatBreathing {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-7px); }
}

.gift-box {
  width: 144px;
  height: 134px;
  position: relative;
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: transform 0.25s ease;
}

/* Animation rung lắc mời gọi tương tác khi hover hoặc touch */
.gift-box:hover,
.gift-box:focus {
  animation: gentleShake 0.65s ease-in-out;
}

@keyframes gentleShake {
  0% { transform: rotate(0deg) scale(1); }
  20% { transform: rotate(-4deg) scale(1.03); }
  40% { transform: rotate(4deg) scale(1.03); }
  60% { transform: rotate(-3deg) scale(1.02); }
  80% { transform: rotate(2deg) scale(1.01); }
  100% { transform: rotate(0deg) scale(1); }
}

/* Thân hộp quà: Màu đỏ nhung trầm ấm có chiều sâu */
.gift-body {
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 124px;
  height: 94px;
  background: linear-gradient(150deg, #c74733 0%, #a43321 100%);
  border-radius: 0 0 14px 14px;
  box-shadow: inset 0 -6px 14px rgba(0, 0, 0, 0.16),
              0 14px 28px rgba(164, 51, 33, 0.26);
  overflow: hidden;
  z-index: 2;
}

/* Dải ruy băng lụa vàng ánh kim */
.gift-body .body-ribbon-v {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 22px;
  background: linear-gradient(90deg, #fae2a8 0%, #e6b35d 50%, #fae2a8 100%);
  box-shadow: 0 0 6px rgba(230, 179, 93, 0.35);
}

.gift-body .body-ribbon-h {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  transform: translateY(-50%);
  height: 22px;
  background: linear-gradient(180deg, #fae2a8 0%, #e6b35d 50%, #fae2a8 100%);
  box-shadow: 0 0 6px rgba(230, 179, 93, 0.35);
}

/* Nắp hộp quà */
.gift-lid {
  position: absolute;
  top: 22px;
  left: 50%;
  transform: translateX(-50%);
  width: 138px;
  height: 28px;
  background: linear-gradient(150deg, #d3523d 0%, #b03a27 100%);
  border-radius: 7px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.16);
  z-index: 4;
  transform-origin: left bottom;
  transition: transform 0.65s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.6s ease;
}

.gift-lid .lid-ribbon {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 22px;
  background: linear-gradient(90deg, #fae2a8 0%, #e6b35d 50%, #fae2a8 100%);
}

/* Nơ lụa phía trên nắp */
.gift-bow {
  position: absolute;
  top: 5px;
  left: 50%;
  transform: translateX(-50%);
  width: 54px;
  height: 26px;
  z-index: 5;
  transform-origin: center bottom;
  transition: transform 0.65s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.6s ease;
}

.bow-loop {
  position: absolute;
  top: 0;
  width: 26px;
  height: 20px;
  border: 4px solid #fae2a8;
  border-radius: 50% 50% 10% 50%;
  background: linear-gradient(135deg, #e6b35d, #fae2a8);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.12);
}

.bow-left {
  left: 1px;
  transform: rotate(-30deg);
}

.bow-right {
  right: 1px;
  border-radius: 50% 50% 50% 10%;
  transform: rotate(30deg);
}

.bow-knot {
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 15px;
  height: 13px;
  background: linear-gradient(135deg, #fae2a8, #caa049);
  border-radius: 4px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.22);
}

/* Bóng đổ chân thực dưới đáy hộp */
.gift-shadow {
  position: absolute;
  bottom: -11px;
  left: 50%;
  transform: translateX(-50%);
  width: 114px;
  height: 15px;
  background: radial-gradient(ellipse at center, rgba(140, 60, 45, 0.28) 0%, rgba(0, 0, 0, 0) 70%);
  border-radius: 50%;
  z-index: 1;
  transition: transform 0.6s ease, opacity 0.6s ease;
}

/* Trạng thái sau khi click: HỘP QUÀ MỞ NẮP */
.gift-box.opened {
  animation: none;
}

.gift-box.opened .gift-lid {
  transform: translate(-50%, -50px) rotate(-22deg) scale(1.05);
}

.gift-box.opened .gift-bow {
  transform: translate(-50%, -64px) rotate(-26deg) scale(1.05);
}

.gift-box.opened .gift-shadow {
  transform: translateX(-50%) scale(0.88);
  opacity: 0.5;
}

/* ==========================================================================
   NÚT MỞ QUÀ: THIẾT KẾ NHƯ CON DẤU NIÊM PHONG (WAX SEAL / GIFT TAG)
   ========================================================================== */
.gift-action {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.open-gift-btn {
  background: linear-gradient(135deg, #ba4732 0%, #9e3724 100%);
  color: #ffffff;
  border: 1px solid rgba(255, 230, 205, 0.35);
  font-family: var(--font-main);
  font-size: 1.08rem;
  font-weight: 600;
  padding: 0.95rem 2.4rem;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 6px 22px rgba(186, 71, 50, 0.36), inset 0 1px 0 rgba(255, 255, 255, 0.25);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  letter-spacing: 0.02em;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.3s ease;
  -webkit-tap-highlight-color: transparent;
}

.open-gift-btn:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 8px 28px rgba(186, 71, 50, 0.45);
}

.open-gift-btn:active {
  transform: scale(0.98);
}

.open-gift-btn:disabled {
  opacity: 0.8;
  cursor: default;
  transform: none;
  box-shadow: 0 4px 12px rgba(186, 71, 50, 0.18);
}

.gift-hint {
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: opacity 0.4s ease;
}

/* ==========================================================================
   KHUNG NỘI DUNG BẤT NGỜ (FADE-IN MƯỢT MÀ SAU KHI MỞ QUÀ)
   ========================================================================== */
.surprise-content {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.9s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.surprise-content.hidden {
  display: none;
  opacity: 0;
  transform: translateY(28px);
}

/* ==========================================================================
   CÁC SECTION CHUNG
   ========================================================================== */
.section {
  margin-top: 2.8rem;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 1.65rem;
  font-weight: 700;
  text-align: center;
  color: var(--text-ink);
  margin-bottom: 0.45rem;
  letter-spacing: 0.01em;
}

.section-subtitle {
  font-size: 0.95rem;
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 1.8rem;
}

/* Thẻ (Card) phong cách giấy cao cấp */
.card {
  background-color: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 2.2rem 1.6rem;
  box-shadow: var(--shadow-card);
}

/* ==========================================================================
   LỜI CHÚC (WISH SECTION - THIẾT KẾ BỨC THƯ TÌNH CẢM)
   ========================================================================== */
.wish-card {
  position: relative;
  background: linear-gradient(180deg, #ffffff 0%, #fffdfa 65%, #fbf6ee 100%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-xl);
  padding: 2.8rem 1.8rem 2.4rem;
  box-shadow: var(--shadow-card);
  /* Đường viền chỉ vàng ánh kim thanh lịch */
  outline: 1px solid var(--card-border-gold);
  outline-offset: -12px;
}

/* Huy hiệu phong thư trang nhã */
.letter-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background-color: var(--accent-blush);
  border: 1px solid rgba(194, 146, 85, 0.35);
  color: var(--accent-warm);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.35rem 1rem;
  border-radius: 999px;
  margin-bottom: 1.6rem;
}

.badge-icon {
  font-size: 1.05rem;
}

/* Lời xưng hô đầu thư: Font serif nghiêng sang trọng */
.letter-salutation {
  font-family: var(--font-heading);
  font-size: 1.68rem;
  font-weight: 700;
  font-style: italic;
  color: var(--text-ink);
  text-align: left;
  margin-bottom: 1.4rem;
  line-height: 1.35;
}

/* Khung chứa các đoạn thư */
.letter-content {
  text-align: left;
}

/* Từng đoạn văn trong thư: Chữ to rõ, dòng thoáng dễ đọc */
.letter-paragraph {
  font-size: 1.08rem;
  line-height: 1.95;
  color: var(--text-body);
  margin-bottom: 1.35rem;
}

/* Chữ cái đầu thư kiểu Drop Cap cổ điển */
.letter-paragraph:first-child::first-letter {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-weight: 700;
  color: var(--accent-warm);
  float: left;
  line-height: 1;
  padding-right: 0.5rem;
  padding-top: 0.1rem;
}

/* Đoạn kết nổi bật với lời chúc sinh nhật */
.letter-paragraph.letter-highlight {
  font-size: 1.18rem;
  font-weight: 600;
  color: var(--accent-warm);
  margin-top: 1.8rem;
  margin-bottom: 0.6rem;
  line-height: 1.7;
}

/* Phần chữ ký và gạch phân cách cuối thư */
.letter-footer {
  margin-top: 2rem;
  text-align: right;
}

.letter-divider {
  width: 72px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-gold), transparent);
  margin: 0 0 0.85rem auto;
}

.letter-closing {
  font-family: var(--font-heading);
  font-style: italic;
  font-size: 1.12rem;
  color: var(--accent-warm);
  font-weight: 600;
}

/* ==========================================================================
   HIỆU ỨNG TỪNG ĐOẠN VĂN LẦN LƯỢT FADE-IN NHẸ (STAGGERED FADE-IN)
   ========================================================================== */
.letter-salutation,
.letter-paragraph,
.letter-footer {
  opacity: 0;
  transform: translateY(18px);
  /* Chuyển động nhẹ nhàng, êm dịu */
  transition: opacity 0.95s cubic-bezier(0.22, 1, 0.36, 1),
              transform 0.95s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: opacity, transform;
}

.wish-card.revealed .letter-salutation {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 0.2s;
}

.wish-card.revealed .letter-paragraph:nth-child(1) {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 0.8s;
}

.wish-card.revealed .letter-paragraph:nth-child(2) {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 1.5s;
}

.wish-card.revealed .letter-paragraph:nth-child(3) {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 2.2s;
}

.wish-card.revealed .letter-paragraph:nth-child(4) {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 2.9s;
}

.wish-card.revealed .letter-footer {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 3.5s;
}

/* ==========================================================================
   ALBUM ẢNH GIA ĐÌNH (POLAROID / KEEPSAKE CAROUSEL)
   ========================================================================== */
.carousel-container {
  width: 100%;
  margin-top: 1.6rem;
  user-select: none;
}

.carousel-main {
  position: relative;
  width: 100%;
  display: flex;
  align-items: center;
}

/* Nút điều hướng Trái / Phải: Nút tròn kính mờ sang trọng */
.nav-btn {
  position: absolute;
  top: 40%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--card-border);
  box-shadow: 0 4px 16px rgba(50, 35, 25, 0.14);
  color: var(--text-ink);
  font-size: 1.9rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 10;
  transition: transform 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.prev-btn {
  left: 8px;
}

.next-btn {
  right: 8px;
}

.nav-btn:hover {
  transform: translateY(-50%) scale(1.08);
  background-color: #ffffff;
  box-shadow: 0 6px 20px rgba(50, 35, 25, 0.2);
  border-color: var(--accent-gold);
}

.nav-btn:active {
  transform: translateY(-50%) scale(0.95);
}

/* Khung chiếu ảnh chính: Thiết kế như một khung ảnh in sang trọng */
.slide-viewport {
  width: 100%;
  overflow: hidden;
  border-radius: var(--radius-xl);
  background-color: #ffffff;
  border: 1px solid var(--card-border);
  box-shadow: var(--shadow-card);
  padding: 10px 10px 0;
  touch-action: pan-y pinch-zoom;
}

/* Dải trượt các slide ảnh */
.slide-track {
  display: flex;
  width: 100%;
  transition: transform 0.48s cubic-bezier(0.25, 1, 0.5, 1);
  will-change: transform;
}

/* Từng slide ảnh */
.slide-item {
  min-width: 100%;
  width: 100%;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
}

.slide-image-wrapper {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: 16px;
  background-color: #f7eee4;
  position: relative;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.04);
}

.slide-image-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Khung chú thích ảnh bên dưới: Viết như ghi chú tay kỷ niệm */
.slide-caption-box {
  padding: 1.15rem 1.25rem 1.35rem;
  background: #ffffff;
  text-align: center;
  min-height: 4.4rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.slide-caption-text {
  font-family: var(--font-main);
  font-size: 1.05rem;
  font-weight: 500;
  font-style: italic;
  color: var(--text-ink);
  line-height: 1.55;
}

/* Dải chấm tròn (Indicators: ● ○ ○ ○ ○) */
.carousel-indicators {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  margin-top: 1.4rem;
}

.indicator-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: #dfd5cb;
  border: none;
  padding: 0;
  cursor: pointer;
  transition: transform 0.25s ease, background-color 0.25s ease, width 0.25s ease;
  -webkit-tap-highlight-color: transparent;
}

.indicator-dot.active {
  width: 26px;
  border-radius: 999px;
  background-color: var(--accent-warm);
  transform: scale(1.05);
  box-shadow: 0 2px 8px rgba(186, 71, 50, 0.3);
}

/* Dải ảnh thu nhỏ (Thumbnails) */
.carousel-thumbnails {
  display: none;
  margin-top: 1.4rem;
  gap: 0.7rem;
  overflow-x: auto;
  padding: 0.4rem 0.2rem 0.6rem;
  scroll-behavior: smooth;
  justify-content: center;
  flex-wrap: wrap;
}

.thumb-item {
  width: 62px;
  height: 46px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  opacity: 0.65;
  transition: transform 0.2s ease, opacity 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
  flex-shrink: 0;
  padding: 0;
  background: #ffffff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.thumb-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.thumb-item:hover {
  opacity: 0.95;
  transform: translateY(-2px);
}

.thumb-item.active {
  opacity: 1;
  border-color: var(--accent-warm);
  transform: scale(1.08);
  box-shadow: 0 4px 14px rgba(186, 71, 50, 0.32);
}

/* ==========================================================================
   LỜI KẾT & PHÁO HOA: 🎆 HAPPY BIRTHDAY (FINALE SECTION)
   ========================================================================== */
.finale-section {
  position: relative;
  min-height: 84vh;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 3.8rem;
  padding: 1.2rem 0;
}

/* Canvas pháo hoa nhẹ nhàng cho phần kết */
.fireworks-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 5;
  border-radius: var(--radius-xl);
}

.finale-card {
  position: relative;
  width: 100%;
  background: linear-gradient(150deg, #ffffff 0%, #fff8f2 50%, #fcf0e4 100%);
  border: 2px solid rgba(194, 146, 85, 0.45);
  border-radius: var(--radius-xl);
  padding: 3.5rem 1.6rem 3rem;
  box-shadow: 0 20px 50px rgba(186, 71, 50, 0.12),
              0 4px 16px rgba(194, 146, 85, 0.12);
  outline: 1px solid rgba(194, 146, 85, 0.28);
  outline-offset: -14px;
  text-align: center;
  overflow: hidden;
  z-index: 2;
}

/* Biểu tượng tiệc mừng 🎉 */
.finale-party-icon {
  font-size: 3.2rem;
  line-height: 1;
  margin-bottom: 0.9rem;
  opacity: 0;
  transform: scale(0.6);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* 1. CHÚC MỪNG SINH NHẬT */
.finale-heading {
  font-family: var(--font-heading);
  font-size: 1.95rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-warm);
  line-height: 1.35;
  margin-bottom: 0.7rem;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

/* 2. BA ❤️ MẸ */
.finale-names {
  font-family: var(--font-heading);
  font-size: 2.85rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--text-ink);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin: 1rem 0 1.4rem;
  opacity: 0;
  transform: scale(0.85);
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.25, 1, 0.5, 1);
}

.heart-pulse {
  display: inline-block;
  color: #d13438;
  text-shadow: 0 0 14px rgba(209, 52, 56, 0.35);
  animation: heartPulse 1.4s ease-in-out infinite;
}

@keyframes heartPulse {
  0%, 100% { transform: scale(1); }
  20% { transform: scale(1.22); }
  40% { transform: scale(1.05); }
  60% { transform: scale(1.26); }
}

/* 3. Lời nhắn cuối: Con yêu Ba Mẹ. */
.finale-message {
  font-family: var(--font-heading);
  font-size: 1.38rem;
  font-weight: 600;
  font-style: italic;
  color: #524744;
  margin-bottom: 2.4rem;
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

/* Nút tương tác thả tim */
.finale-action {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

/* Thứ tự xuất hiện Animation */
.finale-card.active .finale-party-icon {
  opacity: 1;
  transform: scale(1);
  transition-delay: 0.1s;
}

.finale-card.active .finale-heading {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 0.4s;
}

.finale-card.active .finale-names {
  opacity: 1;
  transform: scale(1);
  transition-delay: 1.2s;
}

.finale-card.active .finale-message {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 2.0s;
}

.finale-card.active .finale-action {
  opacity: 1;
  transform: translateY(0);
  transition-delay: 2.6s;
}

.primary-btn {
  background: linear-gradient(135deg, #ba4732 0%, #9e3724 100%);
  color: #ffffff;
  border: 1px solid rgba(255, 230, 205, 0.3);
  font-family: var(--font-main);
  font-size: 1.02rem;
  font-weight: 600;
  padding: 0.9rem 2rem;
  border-radius: 999px;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(186, 71, 50, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.primary-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(186, 71, 50, 0.45);
}

.primary-btn:active {
  transform: scale(0.97);
}

/* ==========================================================================
   CHÂN TRANG (FOOTER)
   ========================================================================== */
.footer {
  margin-top: 3.5rem;
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
  padding-top: 1.8rem;
  border-top: 1px solid var(--card-border);
}

/* ==========================================================================
   RESPONSIVE DESIGN (TABLET & DESKTOP)
   ========================================================================== */

/* Tablet (Màn hình từ 576px trở lên) */
@media (min-width: 576px) {
  .main-title {
    font-size: 2.6rem;
  }

  .carousel-thumbnails {
    display: flex;
  }

  .prev-btn {
    left: 4px;
  }

  .next-btn {
    right: 4px;
  }

  .finale-heading {
    font-size: 2.3rem;
  }

  .finale-names {
    font-size: 3.4rem;
  }

  .finale-message {
    font-size: 1.5rem;
  }
}

/* Desktop (Màn hình từ 768px trở lên) */
@media (min-width: 768px) {
  .container {
    padding-top: 2.8rem;
  }

  .hero-screen {
    padding: 3.2rem 0 2.2rem;
  }

  .main-title {
    font-size: 3rem;
  }

  .wish-card {
    padding: 3.5rem 2.5rem 3rem;
  }

  .letter-salutation {
    font-size: 1.85rem;
  }

  .letter-paragraph {
    font-size: 1.12rem;
  }

  .finale-heading {
    font-size: 2.6rem;
  }

  .finale-names {
    font-size: 3.8rem;
  }
}