/* Christmas Red & White Theme */
:root {
    --primary-red: #c41e3a;
    --dark-red: #8b0000;
    --light-red: #ff6b6b;
    --white: #ffffff;
    --off-white: #f8f8f8;
    --cream: #fff5e6;
    --gold: #ffd700;
    --shadow: rgba(0, 0, 0, 0.2);
}

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

body {
    font-family: 'Georgia', 'Times New Roman', serif;
    background: linear-gradient(135deg, var(--cream) 0%, var(--white) 100%);
    min-height: 100vh;
    color: var(--dark-red);
    overflow-x: hidden;
}

/* Snowflakes Animation */
.snowflakes {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.snowflake {
    position: absolute;
    top: -10px;
    color: #d0d0d0;
    font-size: 2em;
    opacity: 0.8;
    animation: fall linear infinite;
    text-shadow: 0 0 2px rgba(255, 255, 255, 0.8);
}

.snowflake:nth-child(1) { left: 10%; animation-duration: 10s; animation-delay: 0s; }
.snowflake:nth-child(2) { left: 30%; animation-duration: 12s; animation-delay: 2s; }
.snowflake:nth-child(3) { left: 50%; animation-duration: 15s; animation-delay: 4s; }
.snowflake:nth-child(4) { left: 70%; animation-duration: 11s; animation-delay: 1s; }
.snowflake:nth-child(5) { left: 85%; animation-duration: 13s; animation-delay: 3s; }
.snowflake:nth-child(6) { left: 95%; animation-duration: 14s; animation-delay: 5s; }

@keyframes fall {
    to {
        transform: translateY(100vh);
    }
}

/* Container */
.container {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 20px;
    background: var(--white);
    border-radius: 20px;
    box-shadow: 0 8px 20px var(--shadow);
}

h1 {
    font-size: 2.5em;
    color: var(--primary-red);
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: 1.2em;
    color: var(--dark-red);
    font-style: italic;
    margin-bottom: 15px;
}

/* Reset Button */
.reset-btn {
    background: transparent;
    border: 2px solid var(--primary-red);
    color: var(--primary-red);
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.9em;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    margin-top: 10px;
}

.reset-btn:hover {
    background: var(--primary-red);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px var(--shadow);
}

/* Envelopes Grid */
.envelopes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

/* Envelope Styles */
.envelope {
    position: relative;
    width: 100%;
    aspect-ratio: 1.5;
    cursor: pointer;
    perspective: 1000px;
    transition: transform 0.3s ease;
}

.envelope:hover {
    transform: translateY(-5px);
}

.envelope.opened {
    cursor: default;
}

.envelope.opened:hover {
    transform: none;
}

.envelope-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.6s;
}

.envelope.opening .envelope-inner {
    transform: rotateY(180deg);
}

.envelope-front,
.envelope-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 15px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 5px 15px var(--shadow);
}

.envelope-front {
    background: linear-gradient(135deg, var(--primary-red) 0%, var(--dark-red) 100%);
    color: var(--white);
}

.envelope-front::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 50px solid transparent;
    border-right: 50px solid transparent;
    border-top: 40px solid var(--white);
    opacity: 0.3;
}

.envelope-back {
    background: var(--white);
    transform: rotateY(180deg);
    color: var(--primary-red);
}

.envelope-number {
    font-size: 3em;
    font-weight: bold;
    margin-bottom: 10px;
}

.envelope-label {
    font-size: 1.1em;
    text-align: center;
}

.gift-icon {
    font-size: 4em;
}

/* Envelope Color Variations */
.envelope:nth-child(1) .envelope-front { background: linear-gradient(135deg, #c41e3a 0%, #8b0000 100%); }
.envelope:nth-child(2) .envelope-front { background: linear-gradient(135deg, #dc143c 0%, #a01829 100%); }
.envelope:nth-child(3) .envelope-front { background: linear-gradient(135deg, #b22222 0%, #800000 100%); }
.envelope:nth-child(4) .envelope-front { background: linear-gradient(135deg, #cd5c5c 0%, #8b3a3a 100%); }
.envelope:nth-child(5) .envelope-front { background: linear-gradient(135deg, #e9967a 0%, #cd6839 100%); }

.envelope.opened .envelope-front {
    background: linear-gradient(135deg, #d3d3d3 0%, #a9a9a9 100%);
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--white);
    border-radius: 20px;
    padding: 30px;
    max-width: 90%;
    max-height: 90%;
    overflow: auto;
    position: relative;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.modal-content.warning {
    max-width: 500px;
    text-align: center;
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 15px;
    background: none;
    border: none;
    font-size: 2em;
    color: var(--primary-red);
    cursor: pointer;
    line-height: 1;
    padding: 0;
    width: 40px;
    height: 40px;
}

.close-btn:hover {
    color: var(--dark-red);
}

#giftDisplay img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 5px 20px var(--shadow);
}

#giftDisplay h2 {
    color: var(--primary-red);
    margin-bottom: 20px;
    font-size: 2em;
}

/* Warning Modal */
.modal-content.warning h2 {
    color: var(--primary-red);
    margin-bottom: 20px;
}

.modal-content.warning p {
    font-size: 1.1em;
    margin-bottom: 30px;
    line-height: 1.6;
}

.button-group {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
}

.btn-primary {
    background: var(--primary-red);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--dark-red);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--shadow);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-red);
    border: 2px solid var(--primary-red);
}

.btn-secondary:hover {
    background: var(--off-white);
    transform: translateY(-2px);
}

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

    .subtitle {
        font-size: 1em;
    }

    .envelopes-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 20px;
    }

    .envelope-number {
        font-size: 2.5em;
    }

    .envelope-label {
        font-size: 0.9em;
    }

    .gift-icon {
        font-size: 3em;
    }

    .modal-content {
        padding: 20px;
    }

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

    .modal-content.warning p {
        font-size: 1em;
    }

    .button-group {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 20px 15px;
        margin-bottom: 20px;
    }

    h1 {
        font-size: 1.5em;
    }

    .envelopes-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
}

/* Animation for opening */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.envelope:hover:not(.opened) .envelope-front {
    animation: pulse 1s infinite;
}