/* ===== CSS Variables (Apple-inspired) ===== */
:root {
    --apple-blue: #007aff;
    --apple-blue-dark: #0056b3;
    --sidebar-bg: #f2f2f7;
    --sidebar-hover: #e5e5ea;
    --sidebar-selected: #007aff;
    --sidebar-selected-text: #ffffff;
    --content-bg: #ffffff;
    --border-color: #d1d1d6;
    --text-primary: #1c1c1e;
    --text-secondary: #636366;
    --text-tertiary: #8e8e93;
    --toolbar-bg: #f2f2f7;
    --toolbar-border: #d1d1d6;
    --tab-bg: #f9f9fb;
    --unread-dot: #007aff;
    --receive-list-bg: #f9f9fb;
    --email-hover: #f0f0f5;
    --email-selected: #dde8ff;
    --email-selected-border: #007aff;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --radius: 0px;
}

/* ===== Reset & Base ===== */
* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    font-size: 14px;
    color: var(--text-primary);
    background: var(--content-bg);
    overflow: hidden;
}

/* ===== No rounded buttons ===== */
.btn {
    border-radius: 0 !important;
}

.btn-primary {
    background-color: var(--apple-blue);
    border-color: var(--apple-blue);
}

.btn-primary:hover {
    background-color: var(--apple-blue-dark);
    border-color: var(--apple-blue-dark);
}

/* ===== Toolbar ===== */
.mail-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    height: 44px;
    min-height: 44px;
    background: var(--toolbar-bg);
    border-bottom: 1px solid var(--toolbar-border);
    position: relative;
    z-index: 10;
}

.app-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    letter-spacing: -0.2px;
}

.toolbar-actions {
    display: flex;
    gap: 6px;
    align-items: center;
}

/* ===== Main Layout ===== */
.mail-layout {
    display: flex;
    height: calc(100vh - 44px);
    overflow: hidden;
}

/* ===== Sidebar ===== */
.mail-sidebar {
    width: 240px;
    min-width: 240px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    padding: 10px 14px 6px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 1px solid var(--border-color);
}

.conversation-list {
    flex: 1;
    overflow-y: auto;
}

.conversation-item {
    display: flex;
    align-items: flex-start;
    padding: 10px 14px;
    cursor: pointer;
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.1s;
    position: relative;
}

.conversation-item:hover {
    background: var(--sidebar-hover);
}

.conversation-item.selected {
    background: var(--sidebar-selected);
}

.conversation-item.selected .conv-label,
.conversation-item.selected .conv-date {
    color: var(--sidebar-selected-text) !important;
}

.conv-info {
    flex: 1;
    min-width: 0;
}

.conv-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    display: block;
}

.conv-date {
    font-size: 11px;
    color: var(--text-tertiary);
    margin-top: 2px;
    display: block;
}

/* ===== Content Area ===== */
.mail-content {
    flex: 1;
    background: var(--content-bg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.empty-state {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

/* ===== Conversation Detail ===== */
.conversation-detail {
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
}

.conversation-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--toolbar-bg);
    min-height: 48px;
}

.conversation-header-title {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.conversation-header-actions {
    display: flex;
    gap: 6px;
    flex-shrink: 0;
    margin-left: 12px;
}

/* ===== Tabs ===== */
.mail-tabs {
    border-bottom: 1px solid var(--border-color);
    background: var(--tab-bg);
}

.mail-tabs .nav-link {
    border-radius: 0 !important;
    color: var(--text-secondary);
    padding: 8px 18px;
    font-size: 13px;
    font-weight: 500;
    border: none;
    border-bottom: 2px solid transparent;
}

.mail-tabs .nav-link:hover {
    color: var(--text-primary);
    background: transparent;
    border-bottom-color: var(--border-color);
}

.mail-tabs .nav-link.active {
    color: var(--apple-blue);
    background: transparent;
    border-bottom: 2px solid var(--apple-blue);
    font-weight: 600;
}

.tab-content-area {
    flex: 1;
    overflow: hidden;
}

.tab-pane {
    display: none;
    height: 100%;
    overflow: hidden;
}

.tab-pane.active {
    display: flex !important;
    flex-direction: column;
}

/* ===== Send Tab ===== */
.send-tab {
    padding: 16px;
    flex: 1;
    overflow-y: auto;
}

.send-tab .form-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    margin-bottom: 4px;
}

.send-tab .form-control,
.send-tab .form-control:focus {
    border-radius: 0 !important;
    border-color: var(--border-color);
    font-size: 14px;
    box-shadow: none;
}

.send-tab .form-control:focus {
    border-color: var(--apple-blue);
}

.send-tab .form-control[readonly] {
    background: #f9f9fb;
    color: var(--text-secondary);
}

.attachment-row {
    display: flex;
    align-items: center;
    gap: 8px;
}

.attachment-info {
    font-size: 13px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.send-actions {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 8px;
    padding: 12px 16px;
    border-top: 1px solid var(--border-color);
    background: var(--tab-bg);
}

/* ===== Receive Tab ===== */
.receive-tab {
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
}

.receive-toolbar {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
    background: var(--tab-bg);
    flex-shrink: 0;
}

.receive-split {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Email List Panel */
.email-list-panel {
    width: 300px;
    min-width: 280px;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--receive-list-bg);
}

.email-list-header {
    padding: 8px 12px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border-bottom: 1px solid var(--border-color);
    background: var(--sidebar-bg);
}

.email-list {
    flex: 1;
    overflow-y: auto;
}

.email-item {
    display: flex;
    align-items: flex-start;
    padding: 8px 10px 8px 6px;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    transition: background-color 0.1s;
    position: relative;
}

.email-item:hover {
    background: var(--email-hover);
}

.email-item.selected {
    background: var(--email-selected);
    border-left: 2px solid var(--email-selected-border);
}

.email-item.selected .email-from,
.email-item.selected .email-subject {
    color: var(--text-primary);
}

.email-checkbox {
    margin-right: 8px;
    margin-top: 2px;
    flex-shrink: 0;
    accent-color: var(--apple-blue);
}

.email-item-content {
    flex: 1;
    min-width: 0;
}

.email-meta {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 4px;
}

.email-from {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
}

.email-from.read {
    font-weight: 400;
    color: var(--text-secondary);
}

.email-date {
    font-size: 11px;
    color: var(--text-tertiary);
    flex-shrink: 0;
}

.email-subject {
    font-size: 12px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-top: 2px;
}

.unread-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--unread-dot);
    position: absolute;
    left: 4px;
    top: 50%;
    transform: translateY(-50%);
    flex-shrink: 0;
}

.no-messages {
    padding: 20px;
    text-align: center;
    color: var(--text-tertiary);
    font-size: 13px;
}

/* Email Content Panel */
.email-content-panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    background: var(--content-bg);
}

.email-content-empty {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
    font-size: 13px;
}

.email-content-header {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--tab-bg);
    flex-shrink: 0;
}

.email-content-meta {
    display: flex;
    align-items: baseline;
    gap: 8px;
    flex-wrap: wrap;
}

.email-content-from {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.email-content-subject {
    font-size: 14px;
    color: var(--text-secondary);
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.email-content-timestamp {
    font-size: 12px;
    color: var(--text-tertiary);
    flex-shrink: 0;
}

.email-content-actions {
    display: flex;
    gap: 6px;
    margin-top: 8px;
}

.email-body {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
    font-size: 14px;
    line-height: 1.6;
    min-height: 0;
}

.email-body-plain {
    white-space: pre-wrap;
    word-wrap: break-word;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

.email-body-html {
    word-wrap: break-word;
}

.email-body iframe {
    width: 100%;
    border: none;
    min-height: 200px;
}

.email-attachment-info {
    padding: 8px 16px;
    border-top: 1px solid var(--border-color);
    background: var(--tab-bg);
    font-size: 12px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

/* ===== Configuration Tab ===== */
.config-tab {
    padding: 16px;
    flex: 1;
    overflow-y: auto;
}

.config-tab .form-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.3px;
    margin-bottom: 4px;
}

.config-tab .form-control,
.config-tab .form-control:focus {
    border-radius: 0 !important;
    border-color: var(--border-color);
    font-size: 14px;
    box-shadow: none;
}

.config-tab .form-control:focus {
    border-color: var(--apple-blue);
}

.config-section {
    margin-bottom: 20px;
    padding: 14px 16px;
    border: 1px solid var(--border-color);
    background: var(--tab-bg);
}

.config-section-title {
    font-size: 12px;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.config-note {
    font-size: 12px;
    color: var(--text-secondary);
    padding: 10px 12px;
    background: #fff3cd;
    border-left: 3px solid #ffc107;
    margin-bottom: 16px;
}

.config-note a {
    color: var(--apple-blue);
    text-decoration: none;
}

.config-note a:hover {
    text-decoration: underline;
}

/* ===== Modal fixes ===== */
.modal-content {
    border-radius: 0 !important;
}

.modal-header {
    border-bottom: 1px solid var(--border-color);
}

.modal-footer {
    border-top: 1px solid var(--border-color);
}

/* ===== Scrollbar styling ===== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: #c7c7cc;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #8e8e93;
}

/* ===== Utilities ===== */
.status-badge {
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 0 !important;
    font-weight: 600;
    letter-spacing: 0.3px;
}

input[type="checkbox"] {
    accent-color: var(--apple-blue);
}

/* ===== Responsive adjustments ===== */
@media (max-width: 900px) {
    .mail-sidebar {
        width: 200px;
        min-width: 200px;
    }
    .email-list-panel {
        width: 250px;
        min-width: 220px;
    }
}