/* --- Global Styles & Setup --- */
@import url('https://fonts.googleapis.com/css2?family=Pacifico&family=Poppins:wght@300;400;700&family=Great+Vibes&display=swap');

:root {
    --bg-dark: #1a1a2e;
    --bg-light: #0f3460;
    --primary-red: #e94560;
    --accent-yellow: #f0e68c;
    --text-light: #ffffff;
    --envelope-body: #f7f3e9;
    --envelope-flap: #e0d9cc;
    --letter-paper: #fffaf0;
    --button-hover: #c73049;
    --cake-bottom: #553c13;
    --cake-middle: #7a522f;
    --cake-top: #9c6e4e;
    --flame-color: orange;
    --shadow-light: rgba(0,0,0,0.2);
    --shadow-medium: rgba(0,0,0,0.3);
    --shadow-heavy: rgba(0,0,0,0.5);
}

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

body {
    font-family: 'Poppins', sans-serif;
    background: linear-gradient(45deg, var(--bg-dark), var(--bg-light));
    color: var(--text-light);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden; /* Prevent scrollbars from animations */
    perspective: 1000px; /* For 3D transforms */
}

.step {
    display: none;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}

.step.active {
    display: flex;
    opacity: 1;
    transform: scale(1);
}

.step:not(.active) {
    opacity: 0;
    transform: scale(0.95);
    pointer-events: none; /* Disable interaction when not active */
}

.action-button {
    padding: 12px 25px;
    background-color: var(--primary-red);
    color: var(--text-light);
    border: none;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 4px 10px var(--shadow-medium);
    letter-spacing: 0.5px;
}

.action-button:hover {
    background-color: var(--button-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px var(--shadow-heavy);
}

/* --- Step 1: Welcome Screen --- */
.welcome-card {
    text-align: center;
    padding: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 15px 30px var(--shadow-heavy);
    max-width: 500px;
    animation: fadeIn 1s ease-out;
}

.welcome-title {
    font-family: 'Great Vibes', cursive;
    font-size: 3.5rem;
    margin-bottom: 20px;
    color: var(--accent-yellow);
    text-shadow: 2px 2px 5px var(--shadow-medium);
}

.welcome-message {
    font-size: 1.2rem;
    margin-bottom: 30px;
    line-height: 1.6;
    color: var(--text-light);
}

/* --- Step 2: Envelope --- */
.envelope-container {
    text-align: center;
    animation: pulse 2s infinite;
    cursor: pointer;
}

.envelope {
    position: relative;
    width: 320px;
    height: 200px;
}

.envelope-back {
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: var(--envelope-body);
    border-radius: 10px;
    box-shadow: 0 8px 20px var(--shadow-medium);
}

.envelope-flap {
    position: absolute;
    width: 100%;
    height: 100px;
    background-color: var(--envelope-flap);
    top: 0;
    left: 0;
    clip-path: polygon(0 0, 100% 0, 50% 100%);
    transform-origin: top;
    transition: transform 0.5s ease-in-out;
    z-index: 2; /* Ensure flap is above other parts */
}

.envelope-front {
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: var(--envelope-body);
    top: 0;
    left: 0;
    clip-path: polygon(0 100%, 100% 100%, 100% 50%, 50% 100%, 0 50%);
    z-index: 1;
}

.envelope-seal {
    position: absolute;
    width: 40px;
    height: 40px;
    /* Base64 for a simple heart SVG icon (red) */
    background-image: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNCAyNCIgZmlsbD0iI2U5NDU2MCI+PHBhdGggZD0iTTEyIDYuMjc1Yy01LjUwMy01LjgyOC0xNC40NDUgMi41NDctNi40NDUgOS42NDcgNC44MjcgNC44MjcgOS4xMjcgMi40NTcgMTIgMi41MjEgMi44NzMtLjA2NCA3LjE3MyAyLjMwMyAxMi0yLjUyMSAxMi03LjA4IDcuNjA4LTExLjQ4NSAyLjc1NS0xMS43OTJjLTcuOTk5LTcuMzk5LTMuMzk1LTkuNzE0LTYuNDQ1LTkuNjQ3eiIvPjwvc3ZnPg==');
    background-size: cover;
    top: 80px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
}

.envelope-container.open .envelope-flap {
    transform: rotateX(180deg);
}

.click-instruction {
    margin-top: 25px;
    font-size: 1.1rem;
    color: var(--accent-yellow);
    animation: bounce 1.5s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* --- Step 3: Letter --- */
.letter-container {
    text-align: center;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 0.5s 0.5s ease, transform 0.5s 0.5s ease;
    max-width: 90vw;
}

.letter-container.show {
    opacity: 1;
    transform: translateY(0);
}

.letter {
    width: 400px;
    max-width: 100%; /* Ensure it fits smaller screens */
    background-color: var(--letter-paper);
    color: var(--bg-dark);
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 10px 20px var(--shadow-medium);
    line-height: 1.8;
}

.letter p {
    font-size: 1.1rem;
    margin-bottom: 20px;
}
.letter p:first-child { font-weight: bold; } /* Dearest [Name], */
.letter p:last-of-type { margin-bottom: 0; }


/* --- Step 4: Grand Celebration --- */
.celebration-container {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.celebration-card {
    text-align: center;
    padding: 30px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 20px;
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.25);
    box-shadow: 0 20px 40px var(--shadow-heavy);
    max-width: 700px;
    z-index: 10; /* Ensure card is above animations */
    animation: popIn 1s cubic-bezier(0.68, -0.55, 0.27, 1.55);
}

@keyframes popIn {
    0% { opacity: 0; transform: scale(0.5); }
    100% { opacity: 1; transform: scale(1); }
}

.sub-greeting {
    font-size: 1.2rem;
    margin-bottom: 5px;
    color: var(--accent-yellow);
}

.main-greeting {
    font-family: 'Poppins', sans-serif;
    font-size: 2.8rem;
    font-weight: 700;
    white-space: nowrap; /* Prevent text wrap during typing */
    overflow: hidden; /* Hide overflow for typewriter effect */
    border-right: 3px solid var(--accent-yellow); /* Typewriter cursor */
    animation: none; /* Handled by JS for typing */
}

/* Typewriter cursor animation (only for final state after typing) */
.main-greeting.typed {
    border-right: 3px solid transparent; /* Hide cursor after typing */
    animation: blinkCursor 0.75s step-end infinite;
}

@keyframes blinkCursor {
    from, to { border-color: transparent }
    50% { border-color: var(--accent-yellow); }
}


.recipient-name {
    font-family: 'Pacifico', cursive;
    font-size: 4.5rem;
    color: var(--accent-yellow);
    margin: 5px 0 20px;
    text-shadow: 3px 3px 8px var(--shadow-medium);
    line-height: 1;
}

.final-wish {
    font-size: 1.15rem;
    margin-top: 25px;
    line-height: 1.6;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.signature {
    font-family: 'Great Vibes', cursive;
    font-size: 2rem;
    margin-top: 30px;
    color: var(--accent-yellow);
    display: flex;
    justify-content: center;
    align-items: center;
}

.heart-icon {
    width: 25px;
    height: 25px;
    margin-left: 10px;
    background-image: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAyNCAyNCIgZmlsbD0iI2U5NDU2MCI+PHBhdGggZD0iTTEyIDYuMjc1Yy01LjUwMy01LjgyOC0xNC40NDUgMi41NDctNi40NDUgOS42NDcgNC44MjcgNC44MjcgOS4xMjcgMi40NTcgMTIgMi41MjEgMi44NzMtLjA2NCA3LjE3MyAyLjMwMyAxMi0yLjUyMSAxMi03LjA4IDcuNjA4LTExLjQ4NSAyLjc1NS0xMS43OTJjLTcuOTk5LTcuMzk5LTMuMzk1LTkuNzE0LTYuNDQ1LTkuNjQ3eiIvPjwvc3ZnPg==');
    background-size: contain;
    background-repeat: no-repeat;
    vertical-align: middle;
}

/* --- Cake Styling --- */
.cake-container {
    margin: 30px auto;
}

.cake {
    position: relative;
    width: 280px; /* Slightly larger cake */
    height: 280px;
    margin: 0 auto; /* Center the cake */
}

.plate {
    width: 300px;
    height: 25px;
    background-color: #ccc;
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 50%;
    box-shadow: 0 5px 10px var(--shadow-medium);
}

.layer {
    position: absolute;
    width: 280px;
    height: 60px; /* Taller layers */
    background-color: var(--cake-bottom);
    border-radius: 50% / 25%;
    left: 50%;
    transform: translateX(-50%);
}
.layer-bottom { bottom: 45px; background-color: var(--cake-bottom); width: 280px; }
.layer-middle { bottom: 85px; background-color: var(--cake-middle); width: 260px; }
.layer-top { bottom: 125px; background-color: var(--cake-top); width: 240px; }

.icing {
    position: absolute;
    width: 240px;
    height: 35px; /* Thicker icing */
    background-color: white;
    bottom: 165px;
    border-radius: 50% / 25%;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: inset 0 -3px 5px rgba(0,0,0,0.1);
}

.drip {
    position: absolute;
    width: 25px; /* Wider drips */
    height: 35px; /* Longer drips */
    background: white;
    border-radius: 50%;
    top: -15px;
}
.drip1 { left: 40px; display:none;}
.drip2 { left: 127px; height: 45px; } /* Slightly longer middle drip */
.drip3 { left: 210px; display: none;}

.candle {
    position: absolute;
    width: 12px; /* Thicker candle */
    height: 60px; /* Taller candle */
    background-color: var(--primary-red);
    bottom: 190px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 5px 5px 0 0;
    box-shadow: inset 0 -2px 5px rgba(0,0,0,0.2);
}

.flame {
    position: absolute;
    width: 12px;
    height: 18px; /* Taller flame */
    background-color: var(--flame-color);
    top: -18px;
    border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
    animation: flicker 1s infinite;
    box-shadow: 0 0 8px var(--flame-color), 0 0 15px var(--flame-color), 0 0 25px var(--flame-color);
    transition: all 0.2s ease-out; /* For hover effect */
}

/* Candle blow-out effect */
.candle:hover .flame {
    opacity: 0;
    transform: scale(0.2) translateY(5px);
    box-shadow: none;
}

@keyframes flicker {
    0%, 100% { transform: scaleY(1) rotate(0deg); opacity: 1; }
    25% { transform: scaleY(0.9) rotate(2deg); opacity: 0.9; }
    50% { transform: scaleY(1.1) rotate(-2deg); opacity: 1; }
    75% { transform: scaleY(0.95) rotate(1deg); opacity: 0.95; }
}


/* --- Balloons Animation --- */
.balloons-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none; /* Allow clicks on elements beneath */
}

.balloon {
    position: absolute;
    width: 60px; /* Larger balloons */
    height: 80px;
    background-color: var(--primary-red);
    border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
    bottom: -100px;
    opacity: 0.7;
    animation: rise 12s linear forwards; /* 'forwards' to stay at end state */
    z-index: 5; /* Below card, above background */
}

.balloon::before { /* Balloon knot */
    content: '';
    position: absolute;
    width: 10px;
    height: 10px;
    background-color: inherit;
    bottom: -5px;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    border-radius: 0 50% 50% 50%;
}

.balloon::after { /* Balloon string */
    content: '';
    position: absolute;
    width: 2px;
    height: 70px;
    background-color: var(--text-light);
    left: 50%;
    top: 80px;
    transform: translateX(-50%);
    opacity: 0.8;
}

@keyframes rise {
    0% { transform: translateY(0) scale(0.8); opacity: 0; }
    5% { opacity: 0.7; transform: translateY(0) scale(1); }
    100% { transform: translateY(-120vh) scale(1); opacity: 0; }
}


/* --- Confetti Cannon --- */
.confetti-cannon-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden; /* Contains confetti */
    z-index: 8; /* Above balloons, below card */
}

.confetti {
    position: absolute;
    width: 8px;
    height: 8px;
    background-color: var(--primary-red); /* Default, overridden by JS */
    opacity: 0;
    animation: confettiFall 3s ease-out forwards;
    transform-origin: center;
}

@keyframes confettiFall {
    0% { transform: translateY(-10vh) rotate(0deg); opacity: 1; }
    100% { transform: translateY(100vh) rotate(720deg); opacity: 0; }
}

/* --- Fireworks Animation (Subtle Background) --- */
.fireworks-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden;
    z-index: 1; /* Below everything else */
}

.firework {
    position: absolute;
    width: 2px;
    height: 2px;
    background-color: var(--accent-yellow);
    border-radius: 50%;
    box-shadow: 0 0 5px var(--accent-yellow);
    animation: launch 4s ease-out forwards;
    opacity: 0;
}

.firework::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: inherit;
    border-radius: 50%;
    transform: scale(0);
    animation: explode 0.8s ease-out 3s forwards; /* Starts after launch */
    opacity: 0;
}

@keyframes launch {
    0% { transform: translateY(0) translateX(0); opacity: 0; }
    10% { opacity: 1; }
    70% { transform: translateY(-70vh) translateX(50px); opacity: 1; }
    100% { transform: translateY(-80vh) translateX(60px); opacity: 0; }
}

@keyframes explode {
    0% { transform: scale(0); opacity: 1; }
    100% { transform: scale(20); opacity: 0; }
}


/* --- Responsive Adjustments --- */
@media (max-width: 768px) {
    .welcome-title { font-size: 2.5rem; }
    .welcome-message { font-size: 1rem; }
    .letter p { font-size: 1rem; }
    .main-greeting { font-size: 2rem; }
    .recipient-name { font-size: 3.5rem; }
    .final-wish { font-size: 1rem; }
    .signature { font-size: 1.5rem; }
    .cake { transform: scale(0.8); }
    .letter { width: 90%; padding: 20px; }
    .envelope { transform: scale(0.8); } /* Scale down envelope */
}

@media (max-width: 480px) {
    .welcome-title { font-size: 2rem; }
    .welcome-message { font-size: 0.9rem; }
    .action-button { padding: 10px 20px; font-size: 1rem; }
    .main-greeting { font-size: 1.8rem; }
    .recipient-name { font-size: 2.8rem; }
    .final-wish { font-size: 0.9rem; }
    .signature { font-size: 1.2rem; }
    .cake { transform: scale(0.7); }
    .envelope { transform: scale(0.7); } /* Even smaller envelope */
}