:root {
    --primary-color: #FF69B4; /* Hot Pink */
    --secondary-color: #FFD700; /* Gold */
    --background-color: #000; /* Updated for night sky */
    --text-color: #333;
    --card-bg: #ffffff;
}

body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    background-image: radial-gradient(ellipse at bottom, #1B2735 0%, #090A0F 100%);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
    perspective: 1000px;
}

/* --- New Celestial Background Effects --- */

.aurora-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
    opacity: 0.4;
}

.aurora {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(0, 255, 255, 0.2) 0%, rgba(255, 0, 255, 0.2) 100%);
    animation: aurora-flow 20s ease-in-out infinite alternate;
}

.aurora:nth-child(2) {
    background: linear-gradient(-45deg, rgba(0, 255, 0, 0.2) 0%, rgba(0, 0, 255, 0.2) 100%);
    animation-delay: -10s;
}

@keyframes aurora-flow {
    from { transform: translateX(-50%) translateY(-50%) rotate(0deg); }
    to { transform: translateX(0%) translateY(0%) rotate(360deg); }
}

.star {
    position: fixed;
    background: white;
    border-radius: 50%;
    z-index: 2;
    animation: twinkle 5s infinite;
}

@keyframes twinkle {
    0%, 100% {
        opacity: 0.6;
        transform: scale(0.9);
        box-shadow: none;
    }
    50% {
        opacity: 1;
        transform: scale(1.1);
        box-shadow: 0 0 8px rgba(255, 255, 255, 0.8), 0 0 2px rgba(255, 255, 255, 1);
    }
}

.shooting-star {
    position: fixed;
    height: 2px;
    background: linear-gradient(-45deg, #fff, rgba(255, 255, 255, 0));
    border-radius: 999px;
    filter: drop-shadow(0 0 6px #fff);
    animation: shooting-animation 3s ease-in-out infinite;
    z-index: 3;
}

@keyframes shooting-animation {
    0% {
        transform: translateX(0) translateY(0) scaleX(1);
        opacity: 1;
    }
    80% {
        opacity: 1;
    }
    100% {
        transform: translateX(300px) translateY(300px) scaleX(3);
        opacity: 0;
    }
}
/* --- End of Celestial Background Effects --- */


.container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Initial overlay to get user interaction for music */
#start-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    z-index: 100;
    cursor: pointer;
    transition: opacity 0.5s ease-out;
}

#start-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.start-button {
    padding: 1rem 2rem;
    font-size: 1.5rem;
    font-weight: 600;
    color: white;
    background: var(--primary-color);
    border: none;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(255, 105, 180, 0.4);
    transition: transform 0.2s, box-shadow 0.2s;
    animation: pulse 2s infinite;
}

.start-button:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(255, 105, 180, 0.6);
}

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

/* Birthday Card Styling */
.birthday-card {
    width: 400px;
    height: 450px;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 1s ease-in-out;
    cursor: pointer;
    z-index: 10;
}

.birthday-card.open {
    transform: rotateY(-180deg);
}

.card-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 0px;
    box-sizing: border-box;
}

.card-front {
    background: var(--card-bg);
    z-index: 2;
    transform: rotateY(0deg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

/* Updated styles for the card front text */
.vibrating-name {
    font-family: 'Pacifico', cursive;
    font-size: 3rem;
    color: var(--primary-color);
    letter-spacing: -2px;
    font-weight: 700;
    text-transform: uppercase;
    animation: vibrate 2s ease-in-out infinite;
    text-shadow: 0px 0px 5px rgba(255, 255, 255, 0.8), 0px 0px 8px rgba(255, 105, 180, 0.5);
    margin: 0;
    padding: 10px 0;
}

.card-front .subtitle {
    font-family: 'Pacifico', cursive;
    font-size: 1.5rem;
    color: #555;
    margin: -10px 0 10px 0;
}

.card-front p {
    font-size: 1rem;
    color: #666;
    margin-top: 10px;
}

/* Banner image styling */
.banner-img {
    max-width: 80%;
    height: auto;
    margin-bottom: 10px;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.1));
}

.card-back {
    background: var(--card-bg);
    transform: rotateY(180deg);
    padding: 25px;
}

.card-back h2 {
    font-family: 'Pacifico', cursive;
    color: var(--primary-color);
    font-size: 2rem;
    margin-top: 0;
    text-align: center;
}

.card-back p {
    font-family: 'Pacifico', cursive;
    font-size: 1.0rem;
    line-height: 1.8;
    text-align: center;
    min-height: 5.2em;
    color: #555;
    margin-top: 0;
}

/* New Balloon Animation */
.balloon {
    position: fixed;
    width: 80px;
    height: 100px;
    opacity: 0.9;
    z-index: 5;
    bottom: -20px;
    animation: riseUp 10s ease-in-out infinite;
    pointer-events: auto;
    transition: filter 0.3s ease;
}

.balloon:hover {
    filter: drop-shadow(0 0 10px white) drop-shadow(0 0 5px rgba(255, 105, 180, 0.7));
    animation: riseUp 10s ease-in-out infinite, jiggle 0.4s ease-in-out infinite;
}

@keyframes riseUp {
    0% {
        transform: translateY(0) rotate(0deg);
    }
    100% {
        transform: translateY(-110vh) rotate(15deg);
    }
}

@keyframes vibrate {
    0%, 7%, 100% { transform: rotateZ(0); }
    15% { transform: rotateZ(-2deg); }
    20% { transform: rotateZ(2deg); }
    25% { transform: rotateZ(-2deg); }
    30% { transform: rotateZ(2deg); }
    35% { transform: rotateZ(0); }
}

@keyframes jiggle {
    0%, 100% { transform: translateX(-1px) rotate(-2deg); }
    50% { transform: translateX(1px) rotate(2deg); }
}

/* Cursor for typewriter effect */
.typing-cursor {
    display: inline-block;
    width: 8px;
    height: 1.2rem;
    background-color: var(--text-color);
    animation: blink-caret .75s step-end infinite;
}

@keyframes blink-caret {
    from, to { background-color: transparent }
    50% { background-color: var(--text-color); }
}

/* Modal Trigger Button */
.modal-trigger-button {
    position: fixed;
    bottom: 25px;
    right: 25px;
    padding: 12px 25px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    font-family: 'Pacifico', cursive;
    font-size: 1.1rem;
    border-radius: 50px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    z-index: 50;
    border: none;
    cursor: pointer;
}

.modal-trigger-button:hover {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 8px 25px rgba(255, 105, 180, 0.5);
}

/* --- Modal Styles (Corrected Architecture) --- */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 200;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.4s ease-in-out;
}

.modal-overlay.visible {
    opacity: 1;
    pointer-events: auto;
}

.modal-overlay.visible .modal-content {
    transform: scale(1);
}

/* This is the outer frame of the modal. It doesn't scroll. */
.modal-content {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 20px;
    width: 90%;
    max-width: 600px;
    text-align: center;
    position: relative;
    transform: scale(0.9);
    transition: transform 0.4s ease-in-out;
    max-height: 85vh; /* Constrains the overall modal height */
    display: flex; /* Using flexbox for robust internal layout */
    flex-direction: column;
}

/* This new inner container holds the text and is scrollable */
.modal-scrollable-content {
    overflow-y: auto; /* Enables vertical scrolling on this element only */
    padding-right: 15px; /* Creates space for the scrollbar */
    margin-right: -15px; /* Pulls the element back to maintain text centering */
}

.modal-content h2 {
    font-family: 'Pacifico', cursive;
    color: var(--primary-color);
    font-size: 2.0rem;
    margin-top: 0;
}

.modal-content p {
    font-family: 'Pacifico', cursive;
    font-size: 0.9rem;
    line-height: 1.8;
    color: #666;
    text-align: left; /* Justified text is easier to read in long paragraphs */
    padding-bottom: 15px; /* Some space at the very end */
}

/* The close button is a child of the non-scrolling frame */
.close-modal {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 2rem;
    font-weight: bold;
    color: #888;
    cursor: pointer;
    transition: color 0.2s;
    z-index: 10; /* Ensures it's above the scrollable content */
}

.close-modal:hover {
    color: #333;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
    .birthday-card {
        width: 70vw;
        height: 40vh;
    }

    .vibrating-name {
        font-size: 2rem;
    }

    .card-front .subtitle {
        font-size: 1.1rem;
    }
    
    .card-back h2 {
        font-size: 1.3rem;
    }

    .card-back p {
        font-size: 0.8rem;
    }
    
    .modal-content h2 {
        font-size: 1.8rem;
    }
    
    .modal-content p {
        font-size: 1.0rem;
    }

    .modal-trigger-button {
        bottom: 5vh;
        left: 50%;
        transform: translateX(-50%);
        right: auto;
        padding: 10px 20px;
        font-size: 1rem;
    }

    .start-button {
        font-size: 1.2rem;
    }
}