/* ==================== VARIABLES & BASE ==================== */
:root {
    --sage-50: #f8faf7;
    --sage-100: #e8ebe3;
    --sage-200: #d4dac9;
    --sage-300: #b5c0a5;
    --sage-400: #95a67f;
    --sage-500: #788c62;
    --sage-600: #5d6f4c;
    --sage-700: #4a5840;
    --sage-800: #3d4834;
    --sage-900: #2d3a28;
    --green-dark: #1f3218;
    --cream: #faf9f6;
}

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

/* Utility classes */
.hidden {
    display: none !important;
}

body {
    font-family: 'Montserrat', sans-serif;
    background-color: var(--cream);
    color: var(--sage-800);
    overflow-x: hidden;
}

/* ==================== FALLING HEARTS ==================== */
.heart {
    position: fixed;
    top: -5%;
    z-index: 99;
    pointer-events: none;
    animation: fall linear forwards;
    font-size: 14px;
}

.heart-cover {
    position: absolute;
    z-index: 10;
}

@keyframes fall {
    0% {
        transform: translateY(0) rotate(0deg) scale(1);
        opacity: 0.9;
    }
    100% {
        transform: translateY(110vh) rotate(360deg) scale(0.5);
        opacity: 0;
    }
}

/* ==================== COVER SECTION - ENVELOPE DESIGN ==================== */
#cover-section {
    position: fixed;
    inset: 0;
    z-index: 1000;
    background-color: var(--green-dark);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.8s ease, visibility 0.8s ease, transform 0.8s ease;
}

#cover-section.opening .envelope-flap {
    transform: rotateX(-180deg);
}

#cover-section.opening .envelope-seal {
    opacity: 0;
    transform: translateX(-50%) scale(0);
}

#cover-section.opening .envelope-body {
    transform: translateY(-20px);
}

#cover-section.hidden {
    opacity: 0;
    visibility: hidden;
    transform: scale(1.1);
}

/* Envelope Container */
.envelope-container {
    position: relative;
    width: 320px;
    max-width: 90vw;
}

/* Envelope Body */
.envelope-body {
    background: var(--cream);
    border-radius: 8px;
    padding: 40px 30px 30px;
    text-align: center;
    position: relative;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    z-index: 2;
    transition: transform 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Envelope Flap (Top) */
.envelope-flap {
    position: absolute;
    top: -1px;
    left: 0;
    right: 0;
    height: 80px;
    z-index: 3;
    transform-origin: top center;
    transition: transform 0.8s cubic-bezier(0.34, 1.56, 0.64, 1);
    transform-style: preserve-3d;
    perspective: 1000px;
}

.envelope-flap-inner {
    width: 100%;
    height: 100%;
    background: var(--sage-700);
    clip-path: polygon(0 0, 50% 100%, 100% 0);
    backface-visibility: hidden;
}

/* Heart seal on flap */
.envelope-seal {
    position: absolute;
    top: 50px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 50px;
    background: var(--sage-700);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 4;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.envelope-seal i {
    color: white;
    font-size: 24px;
}

/* Envelope content */
.envelope-content {
    padding-top: 30px;
}

.envelope-content h1 {
    font-family: 'Great Vibes', cursive;
    font-size: 42px;
    color: var(--sage-700);
    margin-bottom: 10px;
}

.envelope-divider {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin: 15px 0;
    color: var(--sage-400);
}

.envelope-divider span {
    width: 40px;
    height: 1px;
    background: var(--sage-300);
}

.envelope-date {
    font-family: 'Cormorant Garamond', serif;
    font-size: 16px;
    color: var(--sage-500);
    margin-bottom: 15px;
}

.envelope-invite {
    font-family: 'Cormorant Garamond', serif;
    font-style: italic;
    font-size: 18px;
    color: var(--sage-600);
    margin-bottom: 25px;
}

/* Open button */
.open-btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: var(--sage-600);
    color: white;
    border: none;
    padding: 14px 35px;
    border-radius: 50px;
    font-family: 'Montserrat', sans-serif;
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(93, 111, 76, 0.4);
}

.open-btn:hover {
    background: var(--sage-700);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(93, 111, 76, 0.5);
}

.open-btn i {
    transition: transform 0.3s ease;
}

.open-btn:hover i {
    transform: rotate(10deg);
}

/* Dots decoration */
.envelope-dots {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 20px;
}

.envelope-dots span {
    width: 6px;
    height: 6px;
    background: var(--sage-300);
    border-radius: 50%;
}

/* ==================== MAIN CONTENT ==================== */
#main-content {
    opacity: 0;
    visibility: hidden;
    transition: opacity 1s ease, visibility 1s ease;
}

#main-content.visible {
    opacity: 1;
    visibility: visible;
}

/* ==================== ANIMATIONS ==================== */
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

@keyframes pulse-heart {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.15); }
}

@keyframes shake {
    0%, 100% { transform: rotate(-3deg); }
    50% { transform: rotate(3deg); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.animate-float { animation: float 3s ease-in-out infinite; }
.animate-pulse-heart { animation: pulse-heart 1.2s ease-in-out infinite; }
.animate-shake { animation: shake 0.5s ease-in-out infinite; }
.animate-fade-in-up { animation: fadeInUp 0.8s ease forwards; }
.animate-scale-in { animation: scaleIn 0.5s ease forwards; }

/* ==================== PHOTO FRAMES ==================== */
.photo-frame {
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    background: white;
    padding: 8px;
}

/* ==================== LEAF DECORATIONS ==================== */
.leaf-decoration {
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.1));
}

/* ==================== PARALLAX LEAF BACKGROUND ==================== */
.parallax-container {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.parallax-leaf {
    position: absolute;
    transition: transform 0.1s ease-out;
    will-change: transform;
}

/* ===== Mobile First - Default styles for mobile ===== */
/* Lá từ góc trái trên */
.parallax-leaf.leaf-1 {
    top: -5%;
    left: -10%;
    width: 250px;
    height: auto;
    transform-origin: top left;
}

/* Lá từ góc phải trên */
.parallax-leaf.leaf-2 {
    top: -5%;
    right: -10%;
    width: 250px;
    height: auto;
    transform-origin: top right;
}

/* Lá từ góc trái dưới */
.parallax-leaf.leaf-3 {
    bottom: -1%;
    left: -25%;
    width: 200px;
    height: auto;
    transform-origin: bottom left;
}

/* Lá từ góc phải dưới */
.parallax-leaf.leaf-4 {
    bottom: -5%;
    right: -25%;
    width: 180px;
    height: auto;
    transform-origin: bottom right;
}

/* Lá 5 */
.parallax-leaf.leaf-5 {
    top: -8%;
    left: -15%;
    width: 200px;
    height: auto;
    transform-origin: bottom left;
}

/* Lá 6 */
.parallax-leaf.leaf-6 {
    bottom: 5%;
    right: -25%;
    width: 180px;
    height: auto;
    transform-origin: bottom right;
}

/* Lá 7 */
.parallax-leaf.leaf-7 {
    top: -8%;
    left: -15%;
    width: 250px;
    height: auto;
}

/* Lá 8 */
.parallax-leaf.leaf-8 {
    bottom: -8%;
    left: -15%;
    width: 200px;
    height: auto;
    transform-origin: bottom left;
}

/* Lá 9 */
.parallax-leaf.leaf-9 {
    bottom: -50%;
    right: -20%;
    width: 200px;
    height: auto;
    transform-origin: bottom right;
}

/* ===== Tablet styles ===== */
@media (min-width: 640px) {
    .parallax-leaf.leaf-1 {
        top: -8%;
        left: -30%;
        width: 400px;
    }
    
    .parallax-leaf.leaf-2 {
        top: -6%;
        right: -10%;
        width: 300px;
    }
    
    .parallax-leaf.leaf-3 {
        bottom: -3%;
        left: -15%;
        width: 300px;
    }
    
    .parallax-leaf.leaf-4 {
        bottom: -5%;
        right: -15%;
        width: 220px;
    }
    
    .parallax-leaf.leaf-5 {
        top: -10%;
        left: -10%;
        width: 300px;
    }
    
    .parallax-leaf.leaf-6 {
        bottom: 8%;
        right: -18%;
        width: 250px;
    }
    
    .parallax-leaf.leaf-7 {
        top: -10%;
        left: -10%;
        width: 400px;
    }
    
    .parallax-leaf.leaf-8 {
        bottom: -10%;
        left: -10%;
        width: 300px;
    }
    
    .parallax-leaf.leaf-9 {
        bottom: -60%;
        right: -15%;
        width: 300px;
    }
}

/* ===== Desktop styles ===== */
@media (min-width: 900px) {
    .parallax-leaf.leaf-1 {
        top: -7%;
        left: 1%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-2 {
        top: -5%;
        right: 1%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-3 {
        bottom: -1%;
        left: -20%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-4 {
        bottom: -5%;
        right: -20%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-5 {
        top: -10%;
        left: -10%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-6 {
        bottom: 10%;
        right: -22%;
        width: 700px;
    }
    
    .parallax-leaf.leaf-7 {
        top: -10%;
        left: -10%;
        width: 600px;
    }
    
    .parallax-leaf.leaf-8 {
        bottom: -10%;
        left: -10%;
        width: 400px;
    }
    
    .parallax-leaf.leaf-9 {
        bottom: -70%;
        right: -15%;
        width: 400px;
    }
}

/* ==================== AUTO SCROLL INDICATOR ==================== */
.scroll-indicator {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--sage-500);
    font-size: 12px;
    opacity: 0;
    transition: opacity 0.5s ease;
    z-index: 90;
    pointer-events: none;
}

.scroll-indicator.visible {
    opacity: 1;
}

.scroll-indicator .mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--sage-400);
    border-radius: 12px;
    position: relative;
}

.scroll-indicator .mouse::before {
    content: '';
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--sage-400);
    border-radius: 2px;
    animation: scrollWheel 1.5s ease-in-out infinite;
}

@keyframes scrollWheel {
    0%, 100% { opacity: 1; top: 8px; }
    50% { opacity: 0.5; top: 18px; }
}

/* ==================== RED ENVELOPE (GIFT) ==================== */
.red-envelope {
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 50%, #991b1b 100%);
    border-radius: 8px;
    box-shadow: 0 8px 30px rgba(185, 28, 28, 0.4);
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.red-envelope:hover {
    transform: scale(1.05) rotate(2deg);
    box-shadow: 0 12px 40px rgba(185, 28, 28, 0.5);
}

/* Coin decoration */
.coin {
    width: 24px;
    height: 24px;
    background: linear-gradient(135deg, #fbbf24 0%, #f59e0b 50%, #d97706 100%);
    border-radius: 50%;
    border: 2px solid #fcd34d;
    box-shadow: 0 2px 8px rgba(217, 119, 6, 0.4);
}

/* ==================== GIFT MODAL ==================== */
#gift-modal {
    position: fixed;
    inset: 0;
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

#gift-modal.visible {
    opacity: 1;
    visibility: visible;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    transition: opacity 0.5s ease;
}

.modal-content {
    position: relative;
    z-index: 10;
    background: white;
    border-radius: 24px;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 25px 80px rgba(0,0,0,0.3);
    transform: scale(0.8) translateY(50px);
    opacity: 0;
    transition: transform 0.5s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.5s ease;
}

#gift-modal.visible .modal-content {
    transform: scale(1) translateY(0);
    opacity: 1;
}

.modal-header {
    background: linear-gradient(135deg, var(--sage-600), var(--sage-700));
    color: white;
    padding: 24px;
    border-radius: 24px 24px 0 0;
    text-align: center;
}

.modal-header h3 {
    font-family: 'Great Vibes', cursive;
    font-size: 36px;
}

.modal-body {
    padding: 24px;
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.2);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease, transform 0.3s ease;
    z-index: 10;
}

.modal-close:hover {
    background: rgba(255,255,255,0.3);
    transform: rotate(90deg);
}

/* QR Card */
.qr-card {
    text-align: center;
    padding: 16px;
}

.qr-card img {
    width: 140px;
    height: 140px;
    margin: 0 auto 12px;
    border-radius: 12px;
    background: #f5f5f5;
    padding: 8px;
}

/* QR Section (for single QR display) */
.qr-section {
    text-align: center;
}

.qr-section.hidden {
    display: none;
}

.qr-card-single {
    text-align: center;
    padding: 16px;
}

.qr-card-single img {
    width: 200px;
    height: 200px;
    margin: 0 auto;
    border-radius: 16px;
    background: #f5f5f5;
    padding: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

/* ==================== PHOTO LIGHTBOX ==================== */
.photo-lightbox {
    position: fixed;
    inset: 0;
    z-index: 3000;
    background: rgba(0, 0, 0, 0.95);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.4s ease, visibility 0.4s ease;
}

.photo-lightbox.visible {
    opacity: 1;
    visibility: visible;
}

.lightbox-backdrop {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    z-index: 10;
}

.lightbox-close:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
}

.lightbox-counter {
    position: absolute;
    top: 20px;
    left: 20px;
    color: white;
    font-size: 16px;
    font-weight: 500;
    background: rgba(0, 0, 0, 0.5);
    padding: 8px 16px;
    border-radius: 20px;
    z-index: 10;
}

.lightbox-main {
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
    width: 100%;
    height: 100%;
    padding: 70px 60px 100px;
    gap: 10px;
    position: relative;
}

.lightbox-image-container {
    max-width: 100%;
    max-height: 100%;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lightbox-image-container img {
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    object-fit: contain;
    border-radius: 4px;
    animation: lightboxImageIn 0.3s ease;
    will-change: transform, opacity;
}

@keyframes lightboxImageIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.lightbox-nav {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 20;
}

.lightbox-nav.lightbox-prev {
    left: 15px;
}

.lightbox-nav.lightbox-next {
    right: 15px;
}

.lightbox-nav:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-50%) scale(1.1);
}

.lightbox-thumbnails {
    display: flex;
    gap: 10px;
    padding: 15px 20px;
    overflow-x: auto;
    max-width: 100%;
    scrollbar-width: thin;
    scrollbar-color: rgba(255,255,255,0.3) transparent;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    justify-content: center;
    background: linear-gradient(transparent, rgba(0,0,0,0.5));
}

.lightbox-thumbnails::-webkit-scrollbar {
    height: 6px;
}

.lightbox-thumbnails::-webkit-scrollbar-track {
    background: transparent;
}

.lightbox-thumbnails::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.3);
    border-radius: 3px;
}

.thumbnail {
    width: 60px;
    height: 60px;
    border-radius: 8px;
    overflow: hidden;
    cursor: pointer;
    opacity: 0.5;
    transition: all 0.3s ease;
    flex-shrink: 0;
    border: 2px solid transparent;
}

.thumbnail:hover {
    opacity: 0.8;
}

.thumbnail.active {
    opacity: 1;
    border-color: white;
    transform: scale(1.1);
}

.thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Mobile responsive for lightbox */
@media (max-width: 768px) {
    .lightbox-main {
        padding: 70px 50px 90px;
    }
    
    .lightbox-nav {
        width: 40px;
        height: 40px;
        font-size: 16px;
    }
    
    .lightbox-nav.lightbox-prev {
        left: 5px;
    }
    
    .lightbox-nav.lightbox-next {
        right: 5px;
    }
    
    .lightbox-image-container {
        width: 100%;
        height: 100%;
    }
    
    .thumbnail {
        width: 50px;
        height: 50px;
    }
    
    .lightbox-counter {
        font-size: 14px;
        padding: 6px 12px;
    }
    
    .lightbox-thumbnails {
        padding: 10px 15px;
    }
}

/* ==================== MUSIC BUTTON ==================== */
#music-btn {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 50px;
    height: 50px;
    background: var(--sage-600);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(93, 111, 76, 0.4);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

#music-btn:hover {
    background: var(--sage-700);
    transform: scale(1.1);
}

/* ==================== SCROLLBAR ==================== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: var(--sage-400);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--sage-500);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 640px) {
    .envelope-container {
        width: 280px;
    }
    
    .envelope-content h1 {
        font-size: 36px;
    }
    
    .envelope-body {
        padding: 35px 25px 25px;
    }
}