/* ==========================================================================
   1. VARIABLES & RESET
   ========================================================================== */
:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #e0e7ff;
    --success: #059669;
    --success-hover: #047857;
    --success-light: #d1fae5;
    --danger: #dc2626;
    --danger-hover: #b91c1c;
    --danger-light: #fee2e2;
    --warning: #d97706;
    --warning-light: #fef3c7;
    
    /* Neutral colors */
    --bg-app: #f1f5f9;
    --bg-card: #ffffff;
    --border-color: #cbd5e1;
    --text-main: #0f172a;
    --text-muted: #475569;
    --text-light: #94a3b8;
    
    /* Typography */
    --font-ui: 'Noto Sans Thai', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-print: 'Sarabun', 'TH Sarabun New', sans-serif;
    
    /* Layout */
    --header-height: 64px;
    --sidebar-width: 400px;
    --border-radius: 12px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: var(--font-ui);
    background-color: var(--bg-app);
    color: var(--text-main);
    line-height: 1.6;
    font-size: 16px;
    overflow-x: hidden;
}

/* ==========================================================================
   2. APP CONTAINER & HEADER
   ========================================================================== */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

.app-header {
    height: var(--header-height);
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    box-shadow: var(--shadow-sm);
    z-index: 10;
    flex-shrink: 0;
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.icon-logo {
    color: var(--primary);
}

.header-logo h1 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-main);
}

.header-actions {
    display: flex;
    gap: 12px;
}

/* ==========================================================================
   3. BUTTONS & CONTROLS
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 18px;
    font-family: var(--font-ui);
    font-size: 15px;
    font-weight: 600;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.btn-secondary {
    background-color: #f1f5f9;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: #e2e8f0;
    color: var(--text-main);
}

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

.btn-success:hover {
    background-color: var(--success-hover);
    box-shadow: 0 0 0 3px var(--success-light);
}

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

.btn-danger:hover {
    background-color: var(--danger-hover);
    box-shadow: 0 0 0 3px var(--danger-light);
}

.btn-lg {
    padding: 12px 24px;
    font-size: 17px;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 13px;
    border-radius: 6px;
}

.btn-block {
    width: 100%;
}

/* Form inputs */
.form-control {
    width: 100%;
    padding: 12px;
    font-family: var(--font-ui);
    font-size: 16px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: white;
    color: var(--text-main);
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

textarea.form-control {
    resize: vertical;
}

/* ==========================================================================
   4. SIDEBAR (LEFT PANEL)
   ========================================================================== */
.app-body {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.sidebar-section {
    width: var(--sidebar-width);
    border-right: 1px solid var(--border-color);
    background-color: var(--bg-card);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.sidebar-header h2 {
    font-size: 18px;
    font-weight: 600;
}

.search-box {
    padding: 12px 24px;
    border-bottom: 1px solid #e2e8f0;
    background-color: #f8fafc;
}

.search-input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 12px;
    color: var(--text-light);
    pointer-events: none;
}

.search-input-wrapper input {
    width: 100%;
    padding: 10px 36px 10px 40px;
    font-family: var(--font-ui);
    font-size: 15px;
    border: 1.5px solid var(--border-color);
    border-radius: 8px;
    outline: none;
    transition: all 0.2s ease;
}

.search-input-wrapper input:focus {
    border-color: var(--primary);
    background-color: white;
}

.btn-clear-search {
    position: absolute;
    right: 10px;
    background: none;
    border: none;
    font-size: 20px;
    color: var(--text-light);
    cursor: pointer;
    padding: 0 4px;
}

.btn-clear-search:hover {
    color: var(--text-muted);
}

/* Customer Cards List */
.customer-list-container {
    flex: 1;
    overflow-y: auto;
}

.customer-list {
    padding: 16px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.customer-card {
    background: white;
    border: 1.5px solid #e2e8f0;
    border-radius: 10px;
    padding: 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.customer-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.customer-card.active {
    border-color: var(--primary);
    background-color: #f5f3ff;
    box-shadow: 0 0 0 1px var(--primary);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 8px;
}

.cust-name {
    font-weight: 600;
    font-size: 16px;
    color: var(--text-main);
    line-height: 1.4;
}

.card-actions {
    display: flex;
    gap: 4px;
    opacity: 0.8;
}

.card-actions button {
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    color: var(--text-muted);
    transition: background 0.2s, color 0.2s;
}

.card-actions button:hover {
    background: #e2e8f0;
}

.card-actions button.btn-edit:hover {
    color: var(--primary);
    background: var(--primary-light);
}

.card-actions button.btn-delete:hover {
    color: var(--danger);
    background: var(--danger-light);
}

.cust-details {
    font-size: 14px;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.cust-detail-item {
    display: flex;
    align-items: flex-start;
    gap: 6px;
    line-height: 1.4;
}

.cust-detail-item svg {
    color: var(--text-light);
    margin-top: 2px;
    flex-shrink: 0;
}

.tax-badge {
    display: inline-flex;
    align-items: center;
    background-color: #f1f5f9;
    color: var(--text-muted);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
    border: 1px dashed var(--border-color);
    margin-top: 4px;
    width: fit-content;
}

.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 24px;
    text-align: center;
    color: var(--text-muted);
    gap: 12px;
}

.empty-icon {
    color: var(--text-light);
    stroke-width: 1.5;
}

/* ==========================================================================
   5. PREVIEW & CONTROLS (RIGHT PANEL)
   ========================================================================== */
.preview-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: var(--bg-app);
    overflow-y: auto;
    padding: 24px;
    gap: 24px;
}

/* Control Panel */
.control-panel {
    background: white;
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    display: grid;
    grid-template-columns: 2fr 1.5fr 1.5fr 1fr;
    gap: 20px;
    align-items: end;
}

@media (max-width: 1200px) {
    .control-panel {
        grid-template-columns: 1fr 1fr;
        align-items: start;
    }
}

@media (max-width: 768px) {
    .control-panel {
        grid-template-columns: 1fr;
    }
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group label {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-muted);
}

/* Custom Size CSS styling */
.custom-inputs-wrapper {
    display: flex;
    gap: 12px;
}

.input-inline {
    display: flex;
    align-items: center;
    gap: 4px;
    background: #f8fafc;
    border: 1.5px solid var(--border-color);
    border-radius: 8px;
    padding: 6px 10px;
}

.input-inline input {
    border: none;
    background: transparent;
    padding: 4px 0;
    width: 60px;
    text-align: center;
    font-size: 15px;
    font-weight: 700;
    outline: none;
}

.input-inline span {
    font-size: 13px;
    color: var(--text-muted);
}

.inline-controls {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 16px;
    padding-bottom: 12px;
}

/* Custom Checkbox */
.checkbox-container {
    display: flex;
    align-items: center;
    position: relative;
    padding-left: 28px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500 !important;
    user-select: none;
    color: var(--text-main) !important;
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    left: 0;
    height: 20px;
    width: 20px;
    background-color: #e2e8f0;
    border-radius: 4px;
    border: 1.5px solid var(--border-color);
    transition: all 0.2s ease;
}

.checkbox-container:hover input ~ .checkmark {
    background-color: #cbd5e1;
}

.checkbox-container input:checked ~ .checkmark {
    background-color: var(--primary);
    border-color: var(--primary);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked ~ .checkmark:after {
    display: block;
}

.checkbox-container .checkmark:after {
    left: 6px;
    top: 2px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

/* Slider Style */
.slider-wrapper {
    display: flex;
    align-items: center;
    padding: 10px 0;
}

.slider-wrapper input[type="range"] {
    width: 100%;
    accent-color: var(--primary);
    cursor: pointer;
}

/* Actions Wrapper */
.control-actions-wrapper {
    display: flex;
    gap: 12px;
    width: 100%;
}

.control-actions-wrapper button {
    flex: 1;
}

.btn-print {
    flex: 2 !important;
}

/* ==========================================================================
   6. INTERACTIVE PREVIEW & DRAGGABLE LAYOUT
   ========================================================================== */
.preview-area-wrapper {
    display: flex;
    flex-direction: column;
    gap: 12px;
    flex: 1;
}

.preview-title-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

.preview-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-muted);
}

.envelope-outer {
    background: #cbd5e1;
    border: 2px dashed #94a3b8;
    border-radius: 16px;
    padding: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 480px;
    position: relative;
    overflow: auto;
}

/* Envelope Aspect Ratios based on paper selection */
.envelope-preview {
    background: white;
    box-shadow: var(--shadow-lg);
    border-radius: 6px;
    position: relative;
    padding: 24px;
    transition: box-shadow 0.3s ease;
    font-family: var(--font-print);
    color: black;
    overflow: hidden;
    width: 100%;
}

.envelope-preview.paper-dl {
    max-width: 680px;
    aspect-ratio: 220 / 110;
}

.envelope-preview.paper-c5 {
    max-width: 580px;
    aspect-ratio: 229 / 162;
}

.envelope-preview.paper-c6 {
    max-width: 450px;
    aspect-ratio: 162 / 114;
}

.envelope-preview.paper-label {
    max-width: 400px;
    aspect-ratio: 100 / 150;
    border: 1px dashed #64748b;
}

.envelope-preview.paper-a4 {
    max-width: 420px;
    aspect-ratio: 210 / 297;
    border: 1px dashed #94a3b8;
}

.envelope-preview.paper-a5 {
    max-width: 380px;
    aspect-ratio: 148 / 210;
    border: 1px dashed #94a3b8;
}

.envelope-preview.paper-custom {
    max-width: 600px;
    border: 1px dashed #475569;
}

/* ดึงดูดสายตาตอนลากวาง (Draggable classes) */
.draggable {
    position: absolute !important;
    cursor: move;
    user-select: none;
    border: 1.5px dashed transparent;
    padding: 8px;
    border-radius: 6px;
    transition: border-color 0.15s, background-color 0.15s;
    z-index: 5;
}

.draggable:hover {
    border-color: var(--primary);
    background-color: rgba(79, 70, 229, 0.05);
}

.draggable:active, .draggable.dragging {
    border-color: var(--primary-hover);
    background-color: rgba(79, 70, 229, 0.1);
    box-shadow: var(--shadow-sm);
    z-index: 10;
}

/* รายละเอียดบล็อกผู้ส่ง */
.preview-sender {
    top: 6%;
    left: 5%;
    max-width: 50%;
    line-height: 1.35;
    font-size: 13px;
}

.sender-layout-wrapper {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

/* ขนาดโลโก้คำนวณตามอัตราส่วนของเบราว์เซอร์จริง */
.logo-display-wrapper {
    width: calc(var(--logo-size-mm, 35) * var(--scale-factor, 2.5) * 1px);
    height: calc(var(--logo-size-mm, 35) * var(--scale-factor, 2.5) * 1px);
    border-radius: 6px;
    border: 1px solid #e2e8f0;
    background-color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    flex-shrink: 0;
    transition: width 0.1s, height 0.1s;
}

.logo-display-wrapper img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.sender-text-block {
    display: flex;
    flex-direction: column;
}

.sender-tag {
    font-size: 9px;
    font-weight: 700;
    background: var(--primary-light);
    color: var(--primary);
    padding: 1px 4px;
    border-radius: 3px;
    display: inline-block;
    margin-bottom: 2px;
    width: fit-content;
}

.sender-name {
    font-weight: 700;
    font-size: 14px;
    margin-bottom: 1px;
}

.sender-address {
    white-space: pre-line;
    color: #334155;
}

/* แสตมป์จำลอง */
.postage-stamp-placeholder {
    position: absolute;
    top: 6%;
    right: 5%;
    width: 60px;
    height: 70px;
    border: 2px dashed var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 10px;
    font-weight: bold;
    transform: rotate(3deg);
    background: #fafafa;
    pointer-events: none;
    z-index: 1;
}

.paper-label .postage-stamp-placeholder,
.paper-a4 .postage-stamp-placeholder,
.paper-a5 .postage-stamp-placeholder {
    display: none;
}

/* รายละเอียดบล็อกผู้รับ */
.preview-recipient {
    top: 45%;
    left: 45%;
    width: 60%;
    font-size: var(--preview-font-size, 18px);
    line-height: 1.45;
    color: #000000;
}

.recipient-tag {
    font-size: 10px;
    font-weight: 700;
    background: var(--success-light);
    color: var(--success);
    padding: 1px 6px;
    border-radius: 3px;
    display: inline-block;
    margin-bottom: 4px;
}

.recipient-name {
    font-weight: bold;
    font-size: 1.15em;
    margin-bottom: 4px;
}

.recipient-address {
    white-space: pre-line;
    margin-bottom: 4px;
}

.recipient-tax, .recipient-phone {
    font-size: 0.9em;
    color: #1e293b;
}

/* Instruction Box */
.print-instruction-box {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 16px 20px;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    gap: 8px;
    border-left: 4px solid var(--primary);
}

.instruction-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 15px;
    color: var(--text-main);
}

.info-icon {
    color: var(--primary);
}

.instruction-list {
    padding-left: 20px;
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 14px;
    color: var(--text-muted);
}

/* ==========================================================================
   7. MODALS & FORMS
   ========================================================================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.25s ease;
    z-index: 100;
}

.modal-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

.modal-card {
    background-color: var(--bg-card);
    border-radius: 16px;
    width: 100%;
    max-width: 580px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-20px);
    transition: transform 0.25s ease;
    overflow: hidden;
}

.modal-overlay.open .modal-card {
    transform: translateY(0);
}

.modal-header {
    padding: 18px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: #f8fafc;
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 700;
}

.btn-close-modal {
    background: none;
    border: none;
    font-size: 28px;
    color: var(--text-light);
    cursor: pointer;
    line-height: 1;
}

.btn-close-modal:hover {
    color: var(--text-main);
}

.modal-body {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    max-height: 70vh;
    overflow-y: auto;
}

.section-desc {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.form-row {
    display: flex;
    flex-direction: column;
}

.grid-2-col {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 16px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
}

.form-group label span.required {
    color: var(--danger);
}

.form-group label span.helper-text {
    font-weight: normal;
    font-size: 12px;
    color: var(--primary);
}

/* File Upload custom style */
.file-upload-wrapper {
    position: relative;
    width: 100%;
}

.file-upload-wrapper input[type="file"] {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
    z-index: 2;
}

.logo-preview-container-form {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    background: #f8fafc;
    border: 1.5px dashed var(--border-color);
    padding: 12px;
    border-radius: 8px;
    margin-top: 10px;
}

.preview-thumbnail {
    width: 60px;
    height: 60px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.preview-thumbnail img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.modal-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    background-color: #f8fafc;
}

/* Modal Alert */
.modal-alert {
    max-width: 440px;
    text-align: center;
    padding: 32px 24px;
}

.modal-alert-icon {
    width: 64px;
    height: 64px;
    background-color: var(--danger-light);
    color: var(--danger);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px auto;
}

.modal-alert-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--danger);
    margin-bottom: 8px;
}

.modal-alert-msg {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.5;
    margin-bottom: 24px;
}

.modal-alert-footer {
    display: flex;
    justify-content: center;
}

/* ==========================================================================
   8. AUDIT LOG & TIMELINE UI
   ========================================================================== */
.history-cust-title-block {
    display: flex;
    align-items: center;
    background-color: #f1f5f9;
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 700;
    border-left: 4px solid var(--primary);
    margin-bottom: 12px;
}

.history-cust-title-block .label {
    color: var(--text-muted);
    margin-right: 8px;
}

.history-cust-title-block .val {
    color: var(--text-main);
}

.history-meta-info {
    font-size: 13px;
    color: var(--text-light);
    padding: 0 4px;
    margin-bottom: 20px;
}

.timeline-container {
    display: flex;
    flex-direction: column;
    gap: 18px;
    position: relative;
    padding-left: 20px;
    margin-top: 10px;
    max-height: 48vh;
    overflow-y: auto;
}

.timeline-container::before {
    content: "";
    position: absolute;
    top: 6px;
    left: 7px;
    width: 2px;
    height: calc(100% - 12px);
    background-color: var(--border-color);
}

.timeline-item {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: #f8fafc;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 14px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.timeline-item:hover {
    transform: translateX(2px);
    box-shadow: var(--shadow-sm);
}

.timeline-item::before {
    content: "";
    position: absolute;
    top: 14px;
    left: -17px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--primary);
    border: 2.5px solid white;
    box-shadow: 0 0 0 1px var(--border-color);
    z-index: 2;
}

.timeline-item.first-entry::before {
    background-color: var(--success);
}

.timeline-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
}

.timeline-time {
    font-weight: 700;
    color: var(--text-main);
}

.timeline-action-tag {
    background: var(--primary-light);
    color: var(--primary);
    padding: 2px 8px;
    border-radius: 4px;
    font-weight: 700;
    font-size: 11px;
}

.timeline-item.first-entry .timeline-action-tag {
    background: var(--success-light);
    color: var(--success);
}

.timeline-reason {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-main);
    background: white;
    padding: 8px 12px;
    border-radius: 6px;
    border-left: 3.5px solid var(--primary);
    box-shadow: inset 0 1px 2px rgba(0,0,0,0.02);
}

.timeline-item.first-entry .timeline-reason {
    border-left-color: var(--success);
}

/* Diff Table */
.diff-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
    margin-top: 6px;
    background: white;
}

.diff-table th, .diff-table td {
    border: 1px solid #e2e8f0;
    padding: 6px 10px;
    text-align: left;
}

.diff-table th {
    background: #f1f5f9;
    color: var(--text-muted);
    font-weight: 600;
}

.diff-field {
    font-weight: 700;
    color: var(--text-muted);
    width: 25%;
}

.diff-old {
    color: var(--danger);
    background: var(--danger-light);
    text-decoration: line-through;
    word-break: break-all;
}

.diff-new {
    color: var(--success);
    background: var(--success-light);
    word-break: break-all;
}

/* ==========================================================================
   9. TOAST NOTIFICATION SYSTEM
   ========================================================================== */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 2000;
}

.toast {
    background: white;
    padding: 14px 20px;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 12px;
    border-left: 4px solid var(--primary);
    transform: translateX(120%);
    transition: transform 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    min-width: 280px;
    max-width: 400px;
    font-size: 14px;
    font-weight: 500;
}

.toast.show {
    transform: translateX(0);
}

.toast-success {
    border-left-color: var(--success);
}

.toast-danger {
    border-left-color: var(--danger);
}

.toast-warning {
    border-left-color: var(--warning);
}

/* ==========================================================================
   10. PRINT STYLES (@media print)
   ========================================================================== */
@media print {
    body, html {
        background: white !important;
        color: black !important;
        width: 100% !important;
        height: auto !important;
        overflow: visible !important;
        margin: 0 !important;
        padding: 0 !important;
    }

    .app-header, 
    .sidebar-section, 
    .control-panel, 
    .preview-title-bar,
    .print-instruction-box,
    .modal-overlay,
    .toast-container,
    .postage-stamp-placeholder {
        display: none !important;
    }

    .app-body {
        display: block !important;
        overflow: visible !important;
    }

    .preview-section {
        padding: 0 !important;
        margin: 0 !important;
        background: transparent !important;
        display: block !important;
        overflow: visible !important;
    }

    .envelope-outer {
        border: none !important;
        background: transparent !important;
        padding: 0 !important;
        margin: 0 !important;
        min-height: 0 !important;
        display: block !important;
        overflow: visible !important;
    }

    .envelope-preview {
        border: none !important;
        box-shadow: none !important;
        background: white !important;
        position: relative !important;
        page-break-inside: avoid !important;
        font-family: var(--font-print) !important;
        margin: 0 !important;
        padding: 0 !important;
        max-width: none !important;
        aspect-ratio: auto !important;
        height: 100% !important;
    }

    .paper-dl { width: 220mm !important; height: 110mm !important; }
    .paper-c5 { width: 229mm !important; height: 162mm !important; }
    .paper-c6 { width: 162mm !important; height: 114mm !important; }
    .paper-label { width: 100mm !important; height: 150mm !important; }
    .paper-a4 { width: 210mm !important; height: 297mm !important; }
    .paper-a5 { width: 148mm !important; height: 210mm !important; }

    .draggable {
        position: absolute !important;
        border: none !important;
        background: transparent !important;
        padding: 0 !important;
    }

    .preview-sender {
        font-size: 11pt !important;
        line-height: 1.35 !important;
        font-family: var(--font-print) !important;
        color: #000000 !important;
    }

    .sender-tag {
        display: none !important;
    }

    .sender-name {
        font-size: 12pt !important;
        font-weight: bold !important;
    }

    .logo-display-wrapper {
        border: none !important;
        width: calc(var(--logo-size-mm, 35) * 1mm) !important;
        height: calc(var(--logo-size-mm, 35) * 1mm) !important;
        background: transparent !important;
    }

    .preview-recipient {
        font-family: var(--font-print) !important;
        color: #000000 !important;
    }

    .recipient-tag {
        display: none !important;
    }

    .recipient-name {
        font-size: 18pt !important;
        font-weight: bold !important;
        margin-bottom: 2mm !important;
    }

    .recipient-address {
        font-size: 15pt !important;
        line-height: 1.4 !important;
    }

    .recipient-tax, .recipient-phone {
        font-size: 13pt !important;
    }
}