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

body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #ffd1d1, #fff3d1, #d1ffd1, #d1d1ff);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 1500px;
}

.container {
    max-width: 1200px;
    padding: 20px;
    width: 100%;
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5em;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.calendar {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
    padding: 30px;
    background: linear-gradient(45deg, #fff, #f8f9fa);
    border-radius: 15px;
    box-shadow: 
        0 0 20px rgba(0, 0, 0, 0.1),
        0 0 0 10px #ff9a9e,
        0 0 0 20px #fad0c4;
    position: relative;
}

.window {
    aspect-ratio: 1;
    position: relative;
    cursor: pointer;
    border-radius: 10px;
    transform-style: preserve-3d;
}

.window-placeholder {
    aspect-ratio: 1;
    visibility: hidden;
}

.window-front,
.window-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: transform 0.6s ease-in-out;
}

.window-front {
    background: linear-gradient(45deg, #ff6b6b, #ff8585);
    border: 3px solid #ff4757;
    transform: rotateY(0deg);
    z-index: 2;
}

.window.unlocked .window-front,
.window.animate .window-front {
    background: linear-gradient(45deg, #51cf66, #69db7c);
    border: 3px solid #40c057;
}

.window.bonus.unlocked .window-front {
    background: linear-gradient(45deg, #4a90e2, #5ca0f2);
    border: 3px solid #357abd;
}

.window.bonus.locked .window-front {
    background: linear-gradient(45deg, #ff6b6b, #ff8585);
    border: 3px solid #ff4757;
}

.window-back {
    background: white;
    transform: rotateY(180deg);
    z-index: 1;
}

.window.animate {
    position: fixed;
    z-index: 1000;
}

@keyframes animateToCenter {
    0% {
        transform: scale(1);
    }
    100% {
        transform: scale(2.5);
    }
}

@keyframes animateBack {
    0% {
        transform: scale(2.5);
    }
    100% {
        transform: scale(1);
    }
}

.window.animate-to-center {
    animation: animateToCenter 1.2s ease-in-out forwards;
}

.window.animate-back {
    animation: animateBack 0.8s ease-in-out forwards;
}

.window.opened .window-front {
    transform: rotateY(180deg);
    z-index: 1;
}

.window.opened .window-back {
    transform: rotateY(0deg);
    z-index: 2;
}

.window-number {
    font-size: 2em;
    color: white;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.window.bonus .window-number {
    font-size: 1.5em;
    background: linear-gradient(45deg, #fff, #fff);
    padding: 5px 10px;
    border-radius: 5px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    color: #357abd;
    font-weight: bold;
}

/* Special styling for the fourth bonus panel */
.window.bonus[data-bonus-number="4"] .window-front {
    background: linear-gradient(45deg, #ffd700, #ffa500);
    border: 5px solid #ffd700;
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
}

.window.bonus[data-bonus-number="4"].unlocked .window-front {
    background: linear-gradient(45deg, #ffd700, #ffa500);
    border: 5px solid #ffd700;
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
}

.window.bonus[data-bonus-number="4"] .window-number {
    font-size: 1.8em;
    background: linear-gradient(45deg, #ffd700, #ffa500);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    border: 2px solid #ffd700;
    padding: 8px 15px;
}

.window img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 10px;
}

.countdown {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.2em;
    color: white;
    text-align: center;
    padding: 10px;
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.8);
    width: 80%;
    display: none;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
    z-index: 2;
    font-weight: bold;
}

.countdown.active {
    display: block;
    animation: pulse 2s infinite;
}

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

.star {
    position: absolute;
    color: #ffd700;
    font-size: 1.5em;
    text-shadow: 0 0 5px rgba(255, 215, 0, 0.8);
    z-index: 2;
}

/* Special windows styling */
.window[data-number="14"] .window-number,
.window[data-number="15"] .window-number,
.window[data-number="16"] .window-number {
    font-size: 2.5em;
    background: linear-gradient(45deg, #ffd700, #ffa500);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.window[data-number="14"],
.window[data-number="15"],
.window[data-number="16"] {
    border: 5px solid #ffd700;
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
}

.birthday-text {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 3em;
    color: #ff6b6b;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    z-index: 1001;
    opacity: 0;
    animation: fadeInOut 3s ease-in-out;
    pointer-events: none;
    text-align: center;
    background: linear-gradient(45deg, #ff6b6b, #ffd93d, #6c5ce7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: bold;
}

@keyframes fadeInOut {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    20% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
    80% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
    100% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
}

.fullscreen-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    cursor: pointer;
    padding: 20px;
}

.fullscreen-image {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.5);
    animation: scaleIn 0.3s ease-out;
}

@keyframes scaleIn {
    from {
        transform: scale(0.5);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    .calendar {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
        padding: 15px;
    }

    h1 {
        font-size: 1.8em;
        margin-bottom: 20px;
    }

    .container {
        padding: 10px;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.5em;
    }

    .calendar {
        gap: 10px;
        padding: 10px;
    }
}