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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5em;
    color: #2c3e50;
    margin-bottom: 10px;
}

header p {
    color: #7f8c8d;
    font-size: 1.1em;
}

main {
    background: white;
    border-radius: 8px;
    padding: 30px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.hidden {
    display: none !important;
}

/* Event Card */
.event-card, .welcome-card {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.event-card h2, .welcome-card h2 {
    font-size: 2em;
    color: #2c3e50;
    margin-bottom: 20px;
}

.event-details {
    margin-bottom: 30px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
}

.event-details p {
    margin-bottom: 10px;
}

.event-details strong {
    color: #2c3e50;
}

/* Calendar Buttons */
.calendar-buttons {
    margin: 30px 0;
}

.calendar-buttons h3, .rsvp-section h3 {
    font-size: 1.5em;
    color: #2c3e50;
    margin-bottom: 15px;
}

.button-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 6px;
    text-decoration: none;
    text-align: center;
    font-weight: 500;
    transition: all 0.2s ease;
    border: none;
    cursor: pointer;
    font-size: 1em;
}

.btn-primary {
    background: #3498db;
    color: white;
}

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(52, 152, 219, 0.3);
}

.btn-success {
    background: #27ae60;
    color: white;
}

.btn-success:hover {
    background: #229954;
}

/* RSVP Form */
.rsvp-section {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid #ecf0f1;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #2c3e50;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #ecf0f1;
    border-radius: 6px;
    font-size: 1em;
    transition: border-color 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: #3498db;
}

/* Alerts */
.alert {
    padding: 20px;
    border-radius: 8px;
    margin: 20px 0;
    animation: slideDown 0.3s ease-out;
}

.alert strong {
    display: block;
    font-size: 1.2em;
    margin-bottom: 8px;
}

.alert p {
    margin: 0;
    line-height: 1.6;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 2px solid #c3e6cb;
    box-shadow: 0 2px 8px rgba(39, 174, 96, 0.2);
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 2px solid #f5c6cb;
    box-shadow: 0 2px 8px rgba(231, 76, 60, 0.2);
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border: 2px solid #ffeaa7;
    box-shadow: 0 2px 8px rgba(241, 196, 15, 0.2);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Welcome Card */
.welcome-card {
    text-align: center;
    padding: 40px 20px;
}

.welcome-card p {
    margin-bottom: 15px;
    font-size: 1.1em;
    color: #7f8c8d;
}

.welcome-card code {
    background: #ecf0f1;
    padding: 4px 8px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    color: #e74c3c;
}

/* Responsive */
@media (max-width: 600px) {
    body {
        padding: 10px;
    }

    header h1 {
        font-size: 1.8em;
    }

    main {
        padding: 20px;
    }

    .button-group {
        grid-template-columns: 1fr;
    }
}