/* General Styles & Utilities */
:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;

    --background-light: #f4f7f6;
    --surface-light: #ffffff;
    --text-light: #333;
    --border-light: #e0e0e0;
    --shadow-light: rgba(0, 0, 0, 0.1);

    --background-dark: #2c3e50;
    --surface-dark: #34495e;
    --text-dark: #ecf0f1;
    --border-dark: #4a627a;
    --shadow-dark: rgba(0, 0, 0, 0.3);

    --current-background: var(--background-light);
    --current-surface: var(--surface-light);
    --current-text: var(--text-light);
    --current-border: var(--border-light);
    --current-shadow: var(--shadow-light);
}

body.dark-mode {
    --current-background: var(--background-dark);
    --current-surface: var(--surface-dark);
    --current-text: var(--text-dark);
    --current-border: var(--border-dark);
    --current-shadow: var(--shadow-dark);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--current-text);
    background-color: var(--current-background);
    transition: background-color 0.3s ease, color 0.3s ease;
    padding-top: 60px; /* Space for sticky header */
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

/* Header */
.sticky-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--current-surface);
    border-bottom: 1px solid var(--current-border);
    box-shadow: 0 2px 5px var(--current-shadow);
    z-index: 1000;
    transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 1rem;
}

.header-logo {
    height: 40px;
    margin-right: 1rem;
    max-width: 150px;
    object-fit: contain;
}

.sticky-header h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin: 0;
}

.header-actions {
    display: flex;
    gap: 0.5rem;
}

/* Main Layout */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    padding-top: 1.5rem;
}

@media (min-width: 768px) {
    .main-content {
        flex-direction: row;
    }
}

/* Sidebar */
.sidebar {
    background-color: var(--current-surface);
    border-radius: 8px;
    box-shadow: 0 4px 10px var(--current-shadow);
    padding: 1.5rem;
    flex: 1;
    min-width: 280px;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.sidebar h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.6rem;
}

.settings-section {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--current-border);
}

.settings-section:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.settings-section h3 {
    font-size: 1.2rem;
    color: var(--current-text);
    margin-bottom: 1rem;
}

.logo-preview-container {
    margin-top: 10px;
    border: 1px solid var(--current-border);
    padding: 5px;
    border-radius: 4px;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#logo-preview {
    max-width: 100%;
    max-height: 100px;
    object-fit: contain;
}

/* Invoice Builder Section */
.invoice-builder-section {
    background-color: var(--current-surface);
    border-radius: 8px;
    box-shadow: 0 4px 10px var(--current-shadow);
    padding: 1.5rem;
    flex: 2;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.invoice-builder-section h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
}

.invoice-builder-section h3 {
    font-size: 1.4rem;
    margin-top: 1.5rem;
    margin-bottom: 1rem;
    color: var(--current-text);
}

/* Form Elements */
label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--current-text);
}

input[type="text"],
input[type="number"],
input[type="date"],
input[type="url"],
textarea {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: 1px solid var(--current-border);
    border-radius: 6px;
    background-color: var(--current-background);
    color: var(--current-text);
    font-size: 1rem;
    transition: border-color 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}

input[type="color"] {
    width: 100%;
    height: 40px;
    padding: 0;
    margin-bottom: 1rem;
    border: none;
    background: none;
    cursor: pointer;
}

input[type="text"]:focus,
input[type="number"]:focus,
input[type="date"]:focus,
input[type="url"]:focus,
textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.25);
    outline: none;
}

textarea {
    min-height: 80px;
    resize: vertical;
}

small {
    display: block;
    margin-top: -0.5rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
    font-size: 0.85rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.25rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    border: 1px solid transparent;
    border-radius: 6px;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.btn.primary-btn {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}
.btn.primary-btn:hover {
    background-color: #0056b3;
    border-color: #0056b3;
}

.btn.secondary-btn {
    color: #fff;
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}
.btn.secondary-btn:hover {
    background-color: #545b62;
    border-color: #545b62;
}

.btn.danger-btn {
    color: #fff;
    background-color: var(--danger-color);
    border-color: var(--danger-color);
}
.btn.danger-btn:hover {
    background-color: #bd2130;
    border-color: #bd2130;
}

.btn.small-btn {
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
}

#mode-toggle {
    background-color: var(--current-background);
    border: 1px solid var(--current-border);
    color: var(--current-text);
    font-size: 1.2rem;
    padding: 0.5rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#mode-toggle:hover {
    background-color: var(--current-border);
}

/* Grid Layouts */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

@media (min-width: 600px) {
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.invoice-item-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr) 0.5fr 0.8fr 0.5fr; /* Name, Desc, Qty, Price, Total, Remove */
    gap: 10px;
    align-items: center;
    margin-bottom: 10px;
    padding: 10px;
    border: 1px solid var(--current-border);
    border-radius: 6px;
    background-color: var(--current-background);
    transition: background-color 0.3s ease;
}

.invoice-item-row > input,
.invoice-item-row > span {
    margin-bottom: 0;
}

.invoice-item-row .item-name { grid-column: span 2; } /* Name takes 2 columns on small screens */
.invoice-item-row .item-description { grid-column: span 2; } /* Desc takes 2 columns on small screens */

@media (min-width: 768px) {
    .invoice-item-row {
        grid-template-columns: 2fr 3fr 1fr 1fr 1fr auto; /* Name, Desc, Qty, Price, Total, Remove */
        gap: 15px;
    }
    .invoice-item-row .item-name { grid-column: auto; }
    .invoice-item-row .item-description { grid-column: auto; }
}

.item-total {
    text-align: right;
    font-weight: bold;
    color: var(--primary-color);
    padding: 0.75rem;
    border: 1px solid var(--current-border);
    border-radius: 6px;
    background-color: var(--current-surface);
}

#add-item {
    margin-top: 1rem;
    width: auto;
}

/* Invoice Summary */
.invoice-summary {
    border-top: 1px solid var(--current-border);
    margin-top: 2rem;
    padding-top: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    align-items: flex-end;
}

.summary-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 350px; /* Constrain summary width */
}

.summary-row span, .summary-row label {
    font-weight: 500;
}

.summary-row input {
    width: 80px;
    margin-left: 1rem;
    margin-bottom: 0;
    text-align: right;
    padding: 0.5rem;
}

.summary-row.total-row {
    font-size: 1.3rem;
    font-weight: bold;
    color: var(--primary-color);
    padding-top: 0.75rem;
    border-top: 1px solid var(--current-border);
}

.invoice-actions-bottom {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    justify-content: flex-end;
}

/* Confirmation Message */
.confirmation-message {
    padding: 10px 15px;
    margin-top: 15px;
    border-radius: 4px;
    font-weight: 500;
    text-align: center;
    opacity: 0;
    transition: opacity 0.3s ease-in-out;
}

.confirmation-message.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}
.confirmation-message.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}
.confirmation-message {
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease-in-out;
}
.confirmation-message.show {
    opacity: 1;
    pointer-events: auto;
}

/* Print Styles */
@media print {
    body {
        background-color: #fff;
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
        padding-top: 0;
    }
    .sticky-header, .sidebar, #add-item, .invoice-actions-bottom,
    .remove-item-btn, #mode-toggle, .settings-section, .invoice-builder-section h2,
    .confirmation-message, .header-actions {
        display: none !important;
    }
    .main-content {
        flex-direction: column !important;
        padding: 0;
        margin-top: 0;
    }
    .invoice-builder-section, .container {
        box-shadow: none !important;
        border-radius: 0 !important;
        padding: 0 !important;
        margin: 0 auto !important;
        max-width: 800px !important;
        width: 100% !important;
        background-color: #fff !important;
        color: #000 !important;
    }

    .invoice-item-row {
        grid-template-columns: 2fr 3fr 1fr 1fr 1fr !important;
        gap: 10px !important;
        border: none !important;
        background-color: #fff !important;
        padding: 5px 0 !important;
        margin-bottom: 5px !important;
        border-bottom: 1px solid #eee !important;
    }
    .invoice-item-row:last-of-type {
        border-bottom: none !important;
    }
    .item-total {
        background-color: #fff !important;
        border: none !important;
        color: #000 !important;
        padding: 0 !important;
        font-weight: normal !important;
    }
    .invoice-summary {
        border-top: 2px solid #333 !important;
        margin-top: 2rem !important;
        padding-top: 1rem !important;
    }
    .summary-row.total-row {
        border-top: 2px solid #333 !important;
        color: #000 !important;
    }
    input, textarea {
        border: none !important;
        background-color: transparent !important;
        color: #000 !important;
        padding: 0 !important;
        margin-bottom: 0.5rem !important;
    }
    input[type="number"] {
        text-align: left !important;
    }
    label {
        font-weight: bold !important;
        color: #000 !important;
    }
    h1, h2, h3 {
        color: #000 !important;
    }
    /* Company info at top of print */
    body::before {
        content: attr(data-company-info);
        display: block;
        text-align: center;
        margin-bottom: 20px;
        font-size: 1.2em;
        font-weight: bold;
        white-space: pre-wrap;
        color: #000;
    }

    /* Invoice Title for Print */
    .invoice-builder-section h2::before {
        content: "INVOICE";
        display: block;
        font-size: 2em;
        font-weight: bold;
        text-align: center;
        margin-bottom: 20px;
        color: #000;
    }
    .invoice-builder-section h2 {
        display: none; /* Hide the original H2 */
    }

    /* Client info formatting for print */
    #client-name, #client-address {
        border: 1px solid #ccc !important;
        padding: 8px !important;
        background-color: #f9f9f9 !important;
        margin-bottom: 10px !important;
    }
}