/**
 * AI-Futuristic Design System
 * Implements: SRS 5.1 - 5.10
 */

:root {
    /* 5.1 AI-FUTURISTIC COLOR SCHEME */
    /* PRIMARY PALETTE (Light Mode) */
    --primary-blue: #4285F4;
    --primary-hover: #1967D2;
    --primary-light: #E8F0FE;
    --accent-cyan: #00D9FF;
    --accent-purple: #A142F4;
    --success-green: #34A853;
    --warning-amber: #FBBC04;
    --error-red: #EA4335;

    /* DARK MODE PALETTE (AI-Enhanced) */
    --dark-background: #0B0E11;
    --dark-surface: #1A1D21;
    --dark-surface-elevated: #242831;
    --neon-cyan: #00E5FF;
    --neon-purple: #B388FF;
    --neon-green: #64FFDA;
    --text-primary-dark: #E8EAED;
    --text-secondary-dark: #9AA0A6;
    --border-dark: #3C4043;
    --hover-glow: rgba(0, 229, 255, 0.15);

    /* GRADIENT SYSTEM */
    --gradient-primary: linear-gradient(135deg, #4285F4, #A142F4);
    --gradient-ai-glow: linear-gradient(135deg, #00E5FF, #B388FF);
    --gradient-neural: linear-gradient(45deg, #64FFDA, #00E5FF);
    --gradient-holographic: linear-gradient(135deg, #4285F4 0%, #00E5FF 50%, #B388FF 100%);

    /* SEMANTIC COLORS */
    --color-inbox: #4285F4;
    --color-sent: #34A853;
    --color-drafts: #FBBC04;
    --color-starred: #F9AB00;
    --color-spam: #EA4335;
    --color-trash: #5F6368;
    --color-important: #EA4335;
    --color-archived: #9AA0A6;
    --color-ai-suggested: #00E5FF;
    --color-smart-reply: #B388FF;

    /* 5.2 LAYOUT DIMENSIONS */
    --header-height: 64px;
    --nav-width: 256px;
    --email-item-height: 72px;
    --email-header-height: 120px;

    /* 5.4 TYPOGRAPHY SYSTEM */
    --font-primary: 'Google Sans', 'Roboto', sans-serif;
    --font-mono: 'Roboto Mono', monospace;

    /* 5.5 SPACING SYSTEM */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;

    /* 5.6 ELEVATION & SHADOWS */
    --shadow-level-1: 0 1px 2px rgba(0, 0, 0, 0.1);
    --shadow-level-2: 0 2px 8px rgba(0, 0, 0, 0.15);
    --shadow-level-3: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-ai-glow: 0 0 20px rgba(0, 229, 255, 0.3);

    /* 5.7 ANIMATION & TRANSITIONS */
    --ease-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --ease-standard: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --ease-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
    --ease-bounce: 500ms cubic-bezier(0.68, -0.55, 0.27, 1.55);
}

/* THEME VARIABLES */
body.light-mode {
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F5;
    --bg-elevated: #FFFFFF;
    --text-primary: #202124;
    --text-secondary: #5F6368;
    --border-color: #E0E0E0;
    --input-bg: #F1F3F4;
    --surface-glass: rgba(255, 255, 255, 0.8);
    --border-glass: rgba(0, 0, 0, 0.1);
    --nav-item-active: #E8F0FE;
    --nav-text-active: #1967D2;
}

body.dark-mode {
    --bg-primary: var(--dark-background);
    --bg-secondary: var(--dark-surface);
    --bg-elevated: var(--dark-surface-elevated);
    --text-primary: var(--text-primary-dark);
    --text-secondary: var(--text-secondary-dark);
    --border-color: var(--border-dark);
    --input-bg: var(--dark-surface-elevated);
    --surface-glass: rgba(26, 29, 33, 0.7);
    --border-glass: rgba(255, 255, 255, 0.1);
    --nav-item-active: rgba(66, 133, 244, 0.2);
    --nav-text-active: #8AB4F8;
    --shadow-level-1: 0 1px 2px rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: background-color var(--ease-standard), color var(--ease-standard);
    height: 100vh;
    overflow: hidden;
}

/* 5.2 GMAIL-INSPIRED LAYOUT ARCHITECTURE */

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* HEADER (64px) */
.header {
    height: var(--header-height);
    background-color: var(--bg-elevated);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-level-1);
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-sm) 0 var(--spacing-lg);
    gap: var(--spacing-lg);
    z-index: 100;
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    /* Min-width removed for mobile flexibility */
}

@media (min-width: 1025px) {
    .header-left {
        min-width: 238px;
    }
}

.menu-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 12px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.menu-btn:hover {
    background-color: var(--bg-secondary);
}

.header-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 22px;
    font-weight: 500;
    color: var(--text-secondary);
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 700;
}

/* Search Bar (flex: 1, max 720px) */
.header-search {
    flex: 1;
    max-width: 720px;
    height: 48px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-md);
    transition: background var(--ease-fast), box-shadow var(--ease-fast);
}

.header-search:focus-within {
    background-color: var(--bg-elevated);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1), 0 2px 6px rgba(0, 0, 0, 0.1);
}

.search-icon {
    color: var(--text-secondary);
    margin-right: 12px;
}

.search-input {
    flex: 1;
    border: none;
    background: none;
    outline: none;
    font-size: 16px;
    color: var(--text-primary);
    font-family: var(--font-primary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-left: auto;
    padding-right: var(--spacing-sm);
}

/* AI Assistant Icon */
.header-ai-assistant {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient-ai-glow);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    position: relative;
    transition: transform var(--ease-fast);
}

.header-ai-assistant:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-ai-glow);
}

/* MAIN CONTAINER */
.main-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* NAVIGATION SIDEBAR (256px) */
.navigation {
    width: var(--nav-width);
    background-color: var(--bg-elevated);
    display: flex;
    flex-direction: column;
    padding: var(--spacing-sm) 0;
    overflow-y: auto;
    transition: transform var(--ease-standard);
    z-index: 900;
}

/* Compose Button */
/* Compose Button - Medium Size & Gradient Style */
.compose-button {
    height: 48px;
    /* Medium size (was 56px) */
    min-width: 140px;
    width: fit-content;
    margin: 16px 0 16px 16px;
    padding: 0 24px;
    border-radius: 24px;
    /* Fully rounded */
    background: var(--gradient-primary);
    /* Gradient Style */
    color: white;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-family: var(--font-primary);
    font-weight: 600;
    font-size: 15px;
    /* Slightly larger text for readability on gradient */
    cursor: pointer;
    transition: all var(--ease-fast);
    box-shadow: 0 4px 10px rgba(66, 133, 244, 0.3);
    /* Soft shadow */
    letter-spacing: 0.5px;
}

.compose-button .material-icons {
    font-size: 20px;
}

body.dark-mode .compose-button {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 0 15px rgba(66, 133, 244, 0.4);
    /* Glow in dark mode */
}

.compose-button:hover {
    box-shadow: 0 6px 14px rgba(66, 133, 244, 0.5);
    transform: translateY(-1px);
    filter: brightness(1.1);
}

/* Navigation Items */
.nav-item {
    height: 32px;
    padding: 0 12px 0 26px;
    margin-right: 16px;
    border-radius: 0 16px 16px 0;
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    color: var(--text-primary);
    text-decoration: none;
    transition: background-color var(--ease-fast);
}

.nav-item:hover {
    background-color: var(--bg-secondary);
}

.nav-item.active {
    background-color: var(--nav-item-active);
    color: var(--nav-text-active);
    font-weight: 700;
}

.nav-item material-icons {
    font-size: 20px;
}

.nav-label {
    flex: 1;
    font-size: 14px;
}

.count-badge {
    font-size: 12px;
    font-weight: 700;
}

/* Labels Section */
.labels-section {
    margin-top: auto;
    padding: 16px 26px;
}

.labels-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 8px;
}

.label-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 0;
    text-decoration: none;
    color: var(--text-primary);
    font-size: 14px;
}

.label-dot {
    width: 10px;
    height: 10px;
    border-radius: 3px;
    /* Slightly rounded square */
}

/* EMAIL LIST (flex: 1 | min-320px) */
.email-list {
    flex: 1;
    min-width: 320px;
    background-color: var(--bg-primary);
    border-radius: 16px 16px 0 0;
    /* Modern curved top sheet look common in new Material/Gmail */
    margin-right: 8px;
    /* Tiny gap */
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
    box-shadow: var(--shadow-level-1);
}

.email-list-header {
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    border-bottom: 1px solid var(--border-color);
}

.list-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.pagination {
    font-size: 12px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.email-list-tabs {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: var(--spacing-md);
    padding: 0;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-primary);
}

.email-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    padding: 16px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 3px solid transparent;
    transition: all var(--ease-fast);
}

.email-tab:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.email-tab.active {
    color: var(--primary-blue);
    border-bottom-color: var(--primary-blue);
    background: none;
}

.email-tab .material-icons {
    font-size: 20px;
}

/* 5.3 COMPONENT SPECIFICATIONS: EMAIL LIST ITEM (72px) */
.email-list-content {
    overflow-y: auto;
    flex: 1;
}

.email-item {
    height: 72px;
    /* Enforced */
    display: flex;
    align-items: center;
    padding: 0 16px;
    border-bottom: 1px solid var(--border-color);
    cursor: pointer;
    background-color: var(--bg-primary);
    transition: transform var(--ease-fast), box-shadow var(--ease-fast);
    position: relative;
}

.email-item:hover {
    box-shadow: var(--shadow-level-2);
    z-index: 10;
    transform: translateY(-1px);
}

.email-item.unread {
    background-color: var(--bg-primary);
    /* Gmail keeps white, bold text indicates unread */
}

.email-item.unread .email-sender,
.email-item.unread .email-subject {
    font-weight: 700;
}

.email-item.unread {
    background-color: var(--bg-elevated);
}

body.light-mode .email-item.unread {
    background-color: #FFFFFF;
}

/* For unread, visual distinction */
.email-item.unread::after {
    /* Optional dot or just bold text */
}

/* Layout: Checkbox(20px+16px) | Star(20px+12px) | Sender(200px) | Subject(flex) | Snippet(gray) | Timestamp(80px) */

.email-checkbox {
    margin-right: 16px;
}

.email-star {
    margin-right: 12px;
    color: var(--text-secondary);
}

.email-star.starred {
    color: var(--color-starred);
}

.email-sender {
    width: 200px;
    font-size: 14px;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.email-subject-container {
    flex: 1;
    display: flex;
    align-items: center;
    font-size: 14px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    margin-right: 16px;
}

.email-subject {
    color: var(--text-primary);
}

.email-snippet {
    color: var(--text-secondary);
    font-weight: 400;
    margin-left: 4px;
}

.email-timestamp {
    width: 80px;
    text-align: right;
    font-size: 12px;
    color: var(--text-primary);
}

.email-ai-badge {
    position: absolute;
    top: 8px;
    right: 8px;
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 4px;
    background-color: var(--color-ai-suggested);
    color: #000;
    font-weight: 700;
}

/* Priority Indicator */
.email-item.priority::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--gradient-ai-glow);
}

/* READING PANE (flex: 1.5 | min-480px) */
.reading-pane {
    flex: 1.5;
    min-width: 480px;
    background-color: var(--bg-primary);
    border-left: 1px solid var(--border-color);
    margin-left: 8px;
    border-radius: 16px 16px 0 0;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-level-1);
    overflow: hidden;
}

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

.empty-icon {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.5;
}

/* Email Header (120px) */
.email-header {
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-elevated);
}

.email-subject-large {
    font-size: 24px;
    font-weight: 400;
    /* Gmail style is often regular for large headers */
    color: var(--text-primary);
    margin-bottom: 16px;
    font-family: var(--font-primary);
}

.sender-info-row {
    display: flex;
    align-items: center;
    gap: 12px;
    position: relative;
}

.sender-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.sender-details {
    flex: 1;
}

.sender-name {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-primary);
}

.sender-email {
    font-size: 12px;
    color: var(--text-secondary);
}

.email-header .email-timestamp {
    width: auto;
    /* Override list item fixed width */
    display: flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
}

/* Email Actions Toolbar */
.email-actions {
    display: flex;
    gap: 12px;
    margin-top: 24px;
}

.email-action-button {
    height: 36px;
    padding: 0 20px;
    border-radius: 18px;
    border: none;
    color: white;
    /* Default to white text for gradients */
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-primary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--ease-fast);
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.email-action-button:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    transform: translateY(-1px);
    filter: brightness(1.1);
}

.email-action-button:active {
    transform: translateY(0);
}

.email-action-button .material-icons {
    font-size: 18px;
    color: white;
}

/* Specific Gradient Styles */
#btnReply {
    background: var(--gradient-primary);
    /* Blue-Purple */
}

#btnForward {
    background: linear-gradient(135deg, #00C6FF, #0072FF);
    /* Cyan-Blue */
}

#btnSummary {
    background: var(--gradient-ai-glow);
    /* Cyan-Purple */
    box-shadow: 0 0 10px rgba(0, 229, 255, 0.4);
}

#btnSummary:hover {
    box-shadow: 0 0 20px rgba(0, 229, 255, 0.6);
}

#btnArchive {
    background: linear-gradient(135deg, #FF9966, #FF5E62);
    /* Orange-Red/Pink - distinct from delete */
}

#btnDelete {
    background: linear-gradient(135deg, #fe8c00, #f83600);
    /* Vivid Orange to Red */
    /* Or specifically Red for danger */
    background: linear-gradient(135deg, #ef473a, #cb2d3e);
}

/* Icon Only Buttons (Archive/Delete) override */
.email-action-button.icon-only {
    padding: 0;
    width: 36px;
    justify-content: center;
    border-radius: 50%;
}

/* Email Body */
.email-body {
    flex: 1;
    padding: 24px;
    overflow-y: auto;
    font-size: 14px;
    line-height: 1.6;
    color: var(--text-primary);
    max-width: 800px;
    margin: 0 auto;
}

.email-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 12px;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 500;
}

.badge-blockchain {
    border: 1px solid var(--success-green);
    color: var(--success-green);
}

.badge-ipfs {
    border: 1px solid var(--accent-cyan);
    color: var(--accent-cyan);
}

/* 5.9 GLASSMORPHISM */
.glass-card {
    background: var(--surface-glass);
    backdrop-filter: blur(20px);
    border: 1px solid var(--border-glass);
    box-shadow: var(--shadow-level-3);
    border-radius: 16px;
}

/* Utilities */
.icon-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 8px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background-color: var(--bg-secondary);
}

/* Scrollbars */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-secondary);
}

/* AI Assistant Panel */
.ai-panel {
    position: fixed;
    top: var(--header-height);
    right: 0;
    bottom: 0;
    width: 360px;
    background-color: var(--bg-primary);
    /* Fallback */
    background: var(--surface-glass);
    backdrop-filter: blur(20px);
    border-left: 1px solid var(--border-color);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
    z-index: 900;
    transform: translateX(100%);
    transition: transform var(--ease-standard);
    display: flex;
    flex-direction: column;
}

.ai-panel.open {
    transform: translateX(0);
}

.ai-panel-header {
    height: 60px;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(to right, rgba(66, 133, 244, 0.05), rgba(161, 66, 244, 0.05));
}

.ai-panel-header h3 {
    font-size: 18px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--text-primary);
}

.ai-panel-header .ai-icon {
    font-size: 20px;
    background: var(--gradient-ai-glow);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.close-panel-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 8px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--ease-fast);
}

.close-panel-btn:hover {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.ai-panel-content {
    flex: 1;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* AI Insights Cards */
.ai-insights {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.ai-insights h4 {
    font-size: 14px;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 0.5px;
    font-weight: 600;
}

.insight-card {
    padding: 16px;
    border-radius: 12px;
    background-color: var(--bg-elevated);
    border: 1px solid var(--border-color);
    display: flex;
    gap: 16px;
    align-items: flex-start;
    transition: all var(--ease-fast);
    /* Glassmorphism for cards */
    background: rgba(255, 255, 255, 0.5);
}

body.dark-mode .insight-card {
    background: rgba(36, 40, 49, 0.6);
}

.insight-card:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    background: var(--bg-elevated);
    border-color: var(--accent-cyan);
    transform: translateY(-2px);
}

.insight-card .material-icons {
    color: var(--primary-blue);
    padding: 8px;
    background-color: var(--primary-light);
    border-radius: 8px;
}

body.dark-mode .insight-card .material-icons {
    background-color: rgba(66, 133, 244, 0.2);
}

.insight-card strong {
    display: block;
    margin-bottom: 4px;
    font-size: 14px;
    color: var(--text-primary);
}

.insight-card p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* AI Chat Interface */
.ai-chat {
    flex: 1;
    display: flex;
    flex-direction: column;
    border-top: 1px solid var(--border-color);
    margin-top: auto;
    padding-top: 16px;
}

.chat-messages {
    flex: 1;
    min-height: 200px;
    margin-bottom: 16px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    overflow-y: auto;
}

.chat-message {
    display: flex;
    gap: 12px;
    max-width: 90%;
}

.chat-message.ai-message .material-icons {
    color: var(--accent-purple);
    font-size: 20px;
}

.chat-message p {
    background-color: var(--bg-secondary);
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    border-top-left-radius: 2px;
}

.chat-message.user-message {
    align-self: flex-end;
}

.chat-message.user-message p {
    background: var(--gradient-primary);
    color: white !important;
    /* Force white text */
    border-radius: 12px;
    border-bottom-right-radius: 2px;
}

.chat-input-container {
    display: flex;
    gap: 8px;
    padding: 4px;
    background-color: var(--bg-secondary);
    border-radius: 24px;
    border: 1px solid var(--border-color);
}

.chat-input-container:focus-within {
    border-color: var(--primary-blue);
    background-color: var(--bg-elevated);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

.chat-input {
    flex: 1;
    background: none;
    border: none;
    padding: 8px 16px;
    outline: none;
    font-size: 14px;
    color: var(--text-primary);
}

.send-chat-btn {
    background: var(--gradient-primary);
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform var(--ease-fast);
}

.send-chat-btn:hover {
    transform: scale(1.1);
}

/* Responsive Panel */
@media (max-width: 1024px) {
    .ai-panel {
        width: 100%;
        /* Full screen on mobile */
        top: 0;
        /* Cover header too on mobile */
        z-index: 1001;
        /* Above everything */
    }

    .ai-panel.open .close-panel-btn {
        display: flex;
        /* Ensure close button is visible */
    }
}

/* Compose Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(4px);
}

.modal-overlay.open {
    display: flex;
}

.compose-modal {
    width: 600px;
    height: 500px;
    background: var(--bg-elevated);
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-level-3);
    overflow: hidden;
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.compose-header {
    height: 48px;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    border-bottom: 1px solid var(--border-color);
}

.compose-header h3 {
    font-size: 14px;
    font-weight: 500;
}

.compose-actions {
    display: flex;
    gap: 8px;
}

.compose-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 16px;
    gap: 16px;
}

.compose-input {
    border: none;
    border-bottom: 1px solid var(--border-color);
    padding: 8px 0;
    background: transparent;
    font-size: 14px;
    outline: none;
    color: var(--text-primary);
}

.compose-editor {
    flex: 1;
    outline: none;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text-primary);
    overflow-y: auto;
}

.compose-editor:empty:before {
    content: attr(placeholder);
    color: var(--text-secondary);
}

.compose-footer {
    padding: 16px;
    display: flex;
    align-items: center;
    gap: 16px;
    border-top: 1px solid var(--border-color);
}

.send-btn {
    background: var(--gradient-primary);
    border: none;
    color: white;
    padding: 8px 24px;
    border-radius: 18px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: transform 0.1s;
}

.send-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 5px rgba(66, 133, 244, 0.3);
}

.compose-tools {
    display: flex;
    gap: 8px;
}

/* Minimized State */
.compose-modal.minimized {
    height: 48px;
    /* Header height only */
    width: 260px;
    position: absolute;
    bottom: 0;
    right: 64px;
    border-radius: 8px 8px 0 0;
    transform: none !important;
    /* Override potential animations or flex centering quirks */
    animation: none;
    box-shadow: var(--shadow-level-2);
}

.compose-modal.minimized .compose-body,
.compose-modal.minimized .compose-footer {
    display: none;
}

/* Maximized State */
.compose-modal.maximized {
    width: 100vw;
    height: 100vh;
    border-radius: 0;
    max-width: none;
}

/* Ensure overlay allows positioning for minimized */
.modal-overlay:has(.compose-modal.minimized) {
    align-items: flex-end;
    /* Align to bottom? No, position absolute handles it */
    background: transparent;
    /* Remove dimming background when minimized so user can see app */
    pointer-events: none;
    /* Let clicks pass through overlay area */
}

.modal-overlay:has(.compose-modal.minimized) .compose-modal {
    /* Re-enable clicks on the modal itself */
    pointer-events: auto;
}

/* Settings Panel */
.settings-panel {
    position: fixed;
    top: 64px;
    right: 0;
    bottom: 0;
    width: 320px;
    background: var(--bg-elevated);
    box-shadow: -4px 0 15px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
}

.settings-panel.open {
    transform: translateX(0);
}

.settings-header {
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    border-bottom: 1px solid var(--border-color);
}

.settings-header h3 {
    font-size: 16px;
    font-weight: 500;
}

.settings-content {
    padding: 24px;
    overflow-y: auto;
    flex: 1;
}

.settings-section {
    margin-bottom: 32px;
}

.settings-section h4 {
    font-size: 12px;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.theme-options {
    display: flex;
    gap: 16px;
}

.theme-option {
    flex: 1;
    border: none;
    background: none;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.theme-preview {
    width: 100%;
    height: 60px;
    border-radius: 8px;
    border: 2px solid var(--border-color);
}

.theme-preview.light {
    background: #ffffff;
}

.theme-preview.dark {
    background: #202124;
}

.theme-option.active .theme-preview {
    border-color: var(--primary-blue);
    border-width: 2px;
}

.density-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    font-size: 14px;
}

/* Help Modal functionality provided by .modal-overlay, now just specific styles */
.help-modal {
    width: 500px;
    background: var(--bg-elevated);
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    max-height: 80vh;
}

.modal-header {
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    border-bottom: 1px solid var(--border-color);
}

.help-content {
    padding: 24px;
}

.help-search {
    display: flex;
    align-items: center;
    background: var(--bg-secondary);
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 24px;
    gap: 12px;
}



/* =========================================
   RESPONSIVE DESIGN (Mobile & Tablet) 
   ========================================= */

@media (max-width: 1024px) {
    .reading-pane {
        display: none;
        /* Hide reading pane by default on tablet/mobile */
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        bottom: 0;
        width: 100%;
        margin-left: 0;
        border-radius: 0;
        z-index: 500;
        background: var(--bg-primary);
        transform: translateX(100%);
        transition: transform 0.3s ease;
    }

    .reading-pane.active {
        display: flex;
        transform: translateX(0);
    }

    .navigation {
        position: fixed;
        left: -260px;
        top: 64px;
        bottom: 0;
        z-index: 1000;
        transition: left 0.3s ease;
        box-shadow: 2px 0 10px rgba(0, 0, 0, 0.2);
    }

    .navigation.open {
        left: 0;
    }
}

@media (max-width: 768px) {
    .header-logo .logo-text {
        display: none;
        /* Hide logo text on small screens */
    }

    .header-search {
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        height: 64px;
        z-index: 105;
        background: var(--bg-elevated);
        padding: 0 16px;
        display: none;
        /* Hidden by default, toggleable or just rely on icon? */
        /* For now, let's keep it simple: simpler search bar */
        display: flex;
        border-radius: 0;
        max-width: none;
    }

    .header-search:not(.active) {
        display: none;
    }

    /* Make header nicer */
    .header {
        padding: 0 12px;
        justify-content: space-between;
    }

    .compose-button {
        width: 48px;
        min-width: unset;
        height: 48px;
        border-radius: 50%;
        padding: 0;
        justify-content: center;
    }

    .compose-button span+span {
        display: none;
        /* Hide text "Compose" */
    }

    /* Settings Panel Mobile */
    .settings-panel {
        width: 300px;
        /* Slightly smaller */
    }
}


.help-search input {
    border: none;
    background: none;
    flex: 1;
    outline: none;
    color: var(--text-primary);
    font-size: 14px;
}

.help-topics {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.help-topic {
    padding: 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    transition: background 0.2s;
}

.help-topic:hover {
    background: var(--bg-secondary);
}

.help-footer {
    display: flex;
    justify-content: space-between;
    margin-top: 24px;
}

.text-btn {
    background: none;
    border: none;
    color: var(--primary-blue);
    cursor: pointer;
    font-weight: 500;
}
/* Sidebar Footer */
.nav-footer {
    padding: 16px 24px;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
    font-size: 12px;
    color: var(--text-secondary);
}

.storage-usage {
    margin-bottom: 16px;
}

.usage-text {
    margin-bottom: 8px;
    display: flex;
    justify-content: space-between;
}

.usage-bar {
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    margin-bottom: 8px;
    overflow: hidden;
}

.usage-progress {
    height: 100%;
    background: var(--primary-blue);
    border-radius: 2px;
}

.buy-storage-btn {
    background: none;
    border: none;
    padding: 0;
    color: var(--primary-blue);
    cursor: pointer;
    font-size: 12px;
}

.buy-storage-btn:hover {
    text-decoration: underline;
}

.footer-links {
    margin-bottom: 8px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
}

.footer-links a:hover {
    text-decoration: underline;
}

.footer-powered {
    font-size: 11px;
    opacity: 0.7;
}

/* Density Settings */
.email-list-content.comfortable .email-item {
    height: 56px;
    padding: 0 16px;
}

.email-list-content.compact .email-item {
    height: 40px;
    padding: 0 12px;
}

.email-list-content.compact .email-sender {
    width: 160px; /* Tighter layout */
    font-size: 13px;
}

.email-list-content.compact .email-subject {
    font-size: 13px;
}

/* Ensure Header Buttons are Clickable */
.header-right {
    position: relative;
    z-index: 50;
}

.header-right button,
.header-right .icon-btn {
    position: relative;
    z-index: 51;
}

/* Ensure Close Buttons are Clickable */
.close-panel-btn,
.icon-btn {
    pointer-events: auto;
    cursor: pointer;
    z-index: 1000;
}