:root {
    --primary-color: #2196F3;
    --primary-dark: #1976D2;
    --accent-color: #FF4081;
    --background-color: #f5f5f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-secondary: #757575;
    --danger-color: #f44336;
    --success-color: #4CAF50;
    --warning-color: #FF9800;
    --border-radius: 12px;
    --shadow: 0 2px 5px rgba(0,0,0,0.1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    padding-bottom: 80px; /* Χώρος για το FAB */
}

.app-header {
    background-color: var(--primary-color);
    color: white;
    padding: 16px;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.app-header h1 {
    font-size: 20px;
    font-weight: 500;
}

.container {
    padding: 16px;
    max-width: 600px;
    margin: 0 auto;
}

/* Customer List Styles */
.customer-card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 16px;
    margin-bottom: 12px;
    box-shadow: var(--shadow);
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: transform 0.2s;
}

.customer-card:active {
    transform: scale(0.98);
}

.customer-info h3 {
    font-size: 18px;
    margin-bottom: 4px;
}

.customer-info p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 2px;
}

.expiry-badge {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 16px;
    font-size: 12px;
    font-weight: bold;
    color: white;
    margin-top: 4px;
}

.status-ok {
    background-color: var(--success-color);
}

.status-warning {
    background-color: var(--warning-color);
}

.status-expired {
    background-color: var(--danger-color);
}

.customer-actions {
    display: flex;
    flex-direction: row;
    justify-content: flex-end;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: none;
    font-size: 20px;
    padding: 8px;
    cursor: pointer;
    color: var(--text-secondary);
}

.delete-btn {
    color: var(--danger-color);
}

/* FAB */
.fab {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background-color: var(--accent-color);
    color: white;
    border: none;
    font-size: 32px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    cursor: pointer;
    z-index: 1000;
    transition: transform 0.2s;
}

.fab:active {
    transform: scale(0.9);
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
    opacity: 1;
    transition: opacity 0.3s;
}

.modal.hidden {
    display: none;
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background-color: white;
    padding: 24px;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 400px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}

.modal-content h2 {
    margin-bottom: 20px;
    color: var(--primary-color);
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(33, 150, 243, 0.2);
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 24px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
}

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

.btn-secondary {
    background-color: #e0e0e0;
    color: var(--text-color);
}

.empty-state {
    text-align: center;
    margin-top: 40px;
    color: var(--text-secondary);
}

/* Calendar View Styles */
.hidden {
    display: none !important;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    background-color: white;
    padding: 12px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.calendar-header h2 {
    font-size: 18px;
    color: var(--primary-color);
    margin: 0;
}

.calendar-header .icon-btn {
    color: var(--primary-color);
    font-size: 24px;
}

.calendar-stats {
    text-align: center;
    margin-bottom: 16px;
    color: var(--text-secondary);
    font-size: 14px;
}

.calendar-stats strong {
    color: var(--primary-color);
    font-size: 16px;
}

.calendar-grid-header {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    text-align: center;
    font-weight: bold;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-size: 12px;
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 4px;
    background-color: white;
    padding: 8px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.calendar-day {
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    border-radius: 50%;
    cursor: pointer;
    font-size: 14px;
    position: relative;
    transition: background-color 0.2s;
}

.calendar-day:hover {
    background-color: #f0f0f0;
}

.calendar-day.today {
    border: 2px solid var(--primary-color);
    font-weight: bold;
}

.calendar-day.selected {
    background-color: var(--primary-color) !important;
    color: white !important;
}

.calendar-day.other-month {
    color: #ccc;
    pointer-events: none;
}

.day-badge {
    position: absolute;
    bottom: 2px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--accent-color);
}

.day-count {
    font-size: 10px;
    color: var(--accent-color);
    font-weight: bold;
    margin-top: -2px;
}

.calendar-day.selected .day-count {
    color: white;
}

/* Desktop View */
@media (min-width: 1024px) {
    .container {
        max-width: 1200px;
    }

    .customer-list {
        display: grid;
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
    }

    .customer-card {
        margin-bottom: 0;
        flex-direction: column;
        align-items: flex-start;
        height: 100%;
    }

    .customer-info {
        width: 100%;
        margin-bottom: 12px;
    }

    .customer-actions {
        flex-direction: row;
        justify-content: flex-end;
        width: 100%;
        margin-top: auto;
        border-top: 1px solid #f0f0f0;
        padding-top: 8px;
    }
}