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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #2d1b4e 0%, #4a2c6a 25%, #1e3c72 50%, #2a5298 75%, #1a237e 100%);
    min-height: 100vh;
    padding: 20px;
    color: #fff;
    position: relative;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px;
    background: linear-gradient(135deg, #8b2c9d 0%, #c41e3a 50%, #4a2c6a 100%);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(139, 44, 157, 0.4), 0 0 40px rgba(196, 30, 58, 0.3);
    border: 3px solid #c41e3a;
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(196, 30, 58, 0.1) 0%, transparent 70%);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0%, 100% { transform: rotate(0deg); }
    50% { transform: rotate(180deg); }
}

h1 {
    font-size: 3em;
    margin-bottom: 10px;
    text-shadow: 3px 3px 6px rgba(0, 0, 0, 0.5);
    color: #228b22;
}

.subtitle {
    font-size: 1.2em;
    color: #fff;
    opacity: 0.95;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.day-card {
    aspect-ratio: 1;
    border-radius: 15px;
    cursor: pointer;
    position: relative;
    overflow: visible;
    perspective: 1000px;
    border: 4px solid transparent;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.day-card::before {
    content: '';
    position: absolute;
    top: -4px;
    left: -4px;
    right: -4px;
    bottom: -4px;
    border-radius: 15px;
    padding: 4px;
    background: repeating-linear-gradient(
        45deg,
        #228b22 0px,
        #228b22 10px,
        #ffffff 10px,
        #ffffff 20px
    );
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    z-index: -1;
    pointer-events: none;
}

.door-container {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s ease;
    border-radius: 11px;
    overflow: hidden;
}

.day-card.opening .door-container {
    transform: rotateY(-90deg);
}

.door-front {
    width: 100%;
    height: 100%;
    position: absolute;
    backface-visibility: hidden;
    background: linear-gradient(135deg, #5a4fcf 0%, #4a2c6a 50%, #2d1b4e 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 15px;
    box-shadow: inset 0 0 20px rgba(90, 79, 207, 0.3);
}

.door-back {
    width: 100%;
    height: 100%;
    position: absolute;
    backface-visibility: hidden;
    background: linear-gradient(135deg, #8b2c9d 0%, #c41e3a 50%, #4a2c6a 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 15px;
    transform: rotateY(180deg);
    box-shadow: inset 0 0 30px rgba(139, 44, 157, 0.4);
}

.door-back-content {
    text-align: center;
    padding: 10px;
}

.door-back-content .song-icon {
    font-size: 3em;
    margin-bottom: 10px;
    animation: bounce 1s infinite;
    filter: drop-shadow(0 0 10px rgba(34, 139, 34, 0.6)) drop-shadow(0 0 20px rgba(139, 44, 157, 0.4));
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.door-back-content .play-text {
    color: #228b22;
    font-size: 0.9em;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.door-front::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(196, 30, 58, 0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.day-card:not(.locked):not(.opened):hover .door-front::before {
    opacity: 1;
}

.day-card:not(.locked):not(.opened):hover::before {
    background: repeating-linear-gradient(
        45deg,
        #32cd32 0px,
        #32cd32 10px,
        #ffffff 10px,
        #ffffff 20px
    );
}

.day-card:not(.locked):not(.opened):hover {
    transform: translateY(-5px) scale(1.05);
    box-shadow: 0 10px 25px rgba(34, 139, 34, 0.4), 0 0 30px rgba(139, 44, 157, 0.3);
}

.day-card.locked .door-front {
    background: linear-gradient(135deg, #2c2c2c 0%, #1a1a1a 50%, #2d1b4e 100%);
    cursor: not-allowed;
    opacity: 0.6;
}

.day-card.locked::before {
    background: repeating-linear-gradient(
        45deg,
        #555 0px,
        #555 10px,
        #888 10px,
        #888 20px
    );
}

.day-card.locked {
    cursor: not-allowed;
}

.day-card.locked:hover {
    transform: none;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.day-card.opened .door-front {
    background: linear-gradient(135deg, #8b2c9d 0%, #c41e3a 50%, #4a2c6a 100%);
    opacity: 0.8;
}

.day-card.opened::before {
    background: repeating-linear-gradient(
        45deg,
        #c41e3a 0px,
        #c41e3a 10px,
        #ffffff 10px,
        #ffffff 20px
    );
}

.day-card.opened {
    opacity: 0.7;
    filter: grayscale(20%);
    animation: pulse 2s infinite;
    box-shadow: 0 5px 15px rgba(196, 30, 58, 0.4), 0 0 25px rgba(139, 44, 157, 0.4);
}

.day-card.opened .door-container {
    transform: rotateY(-90deg);
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 5px 15px rgba(196, 30, 58, 0.4), 0 0 25px rgba(139, 44, 157, 0.4);
    }
    50% {
        box-shadow: 0 5px 25px rgba(196, 30, 58, 0.8), 0 0 40px rgba(139, 44, 157, 0.6);
    }
}

.day-number {
    font-size: 2.5em;
    font-weight: bold;
    color: #228b22;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    margin-bottom: 5px;
}

.day-card.locked .day-number {
    color: #888;
}

.door-handle {
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    width: 10px;
    height: 10px;
    background: radial-gradient(circle, #c41e3a 0%, #dc3545 100%);
    border-radius: 50%;
    box-shadow: 0 0 8px rgba(196, 30, 58, 0.6), 0 0 15px rgba(139, 44, 157, 0.4);
    animation: handleGlow 2s ease-in-out infinite;
}

@keyframes handleGlow {
    0%, 100% {
        box-shadow: 0 0 8px rgba(196, 30, 58, 0.6), 0 0 15px rgba(139, 44, 157, 0.4);
    }
    50% {
        box-shadow: 0 0 12px rgba(196, 30, 58, 0.8), 0 0 20px rgba(139, 44, 157, 0.6);
    }
}

.day-label {
    font-size: 0.9em;
    color: #fff;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.day-card.locked .day-label {
    color: #666;
}

.lock-icon {
    font-size: 1.5em;
    margin-top: 5px;
    opacity: 0.5;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.modal-content {
    background: linear-gradient(135deg, #2d1b4e 0%, #4a2c6a 50%, #1e3c72 100%);
    margin: 5% auto;
    padding: 30px;
    border: 3px solid #c41e3a;
    border-radius: 20px;
    width: 90%;
    max-width: 800px;
    box-shadow: 0 20px 60px rgba(139, 44, 157, 0.5), 0 0 40px rgba(90, 79, 207, 0.3);
    position: relative;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    color: #228b22;
    float: right;
    font-size: 35px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    line-height: 1;
}

.close:hover {
    color: #228b22;
    transform: rotate(90deg);
}

.modal-header {
    text-align: center;
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 2px solid #c41e3a;
}

.modal-header h2 {
    color: #228b22;
    font-size: 2em;
    margin-bottom: 10px;
}

.modal-header p {
    color: #fff;
    font-size: 1.2em;
    opacity: 0.9;
}

.video-container {
    position: relative;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.video-container iframe {
    width: 100%;
    aspect-ratio: 16 / 9;
    border: none;
    border-radius: 10px;
    display: block;
}

.video-container > div {
    text-align: center;
    margin-top: 15px;
    padding-top: 15px;
}

.video-container a {
    color: #228b22;
    text-decoration: none;
    font-size: 1.1em;
    display: inline-block;
    padding: 10px 20px;
    background: linear-gradient(135deg, rgba(139, 44, 157, 0.4) 0%, rgba(196, 30, 58, 0.4) 100%);
    border-radius: 10px;
    transition: all 0.3s;
    border: 2px solid #c41e3a;
    box-shadow: 0 0 15px rgba(139, 44, 157, 0.3);
}

.video-container a:hover {
    background: linear-gradient(135deg, rgba(139, 44, 157, 0.6) 0%, rgba(196, 30, 58, 0.6) 100%);
    transform: scale(1.05);
    box-shadow: 0 5px 20px rgba(34, 139, 34, 0.4), 0 0 25px rgba(139, 44, 157, 0.5);
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 {
        font-size: 2em;
    }

    .subtitle {
        font-size: 1em;
    }

    .calendar-grid {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
        gap: 15px;
    }

    .day-number {
        font-size: 2em;
    }

    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 20px;
    }

    .modal-header h2 {
        font-size: 1.5em;
    }
}

/* Enhanced Snowflake animation */
#snowflake-container {
    z-index: 10 !important;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden;
}

@keyframes snowflake-fall {
    0% {
        transform: translateY(-100px) translateX(0) rotate(0deg);
        opacity: 1;
    }
    50% {
        transform: translateY(50vh) translateX(30px) rotate(180deg);
        opacity: 0.9;
    }
    100% {
        transform: translateY(calc(100vh + 100px)) translateX(-30px) rotate(360deg);
        opacity: 0;
    }
}

.snowflake {
    position: fixed;
    top: -50px;
    color: rgba(255, 255, 255, 0.9);
    font-size: 1em;
    animation: snowflake-fall linear forwards;
    pointer-events: none;
    z-index: 10;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.5), 0 0 20px rgba(139, 44, 157, 0.3);
    filter: drop-shadow(0 0 5px rgba(90, 79, 207, 0.5));
    will-change: transform, opacity;
}

.snowflake:nth-child(odd) {
    animation-duration: 4s;
    color: rgba(200, 180, 255, 0.8);
}

.snowflake:nth-child(even) {
    animation-duration: 6s;
    color: rgba(255, 255, 255, 0.9);
    filter: drop-shadow(0 0 8px rgba(196, 30, 58, 0.4));
}