/* === WHATSAPP DESIGN SYSTEM === */
:root {
    /* WhatsApp Official Colors (Light Mode) */
    --wa-primary: #008069;
    --wa-primary-dark: #005C4B;
    --wa-primary-light: #00A884;
    --wa-secondary: #F0F2F5;
    --wa-accent-green: #25D366;
    --wa-accent-blue: #34B7F1;
    --wa-accent-yellow: #FFC107;
    --wa-accent-red: #F44336;
    
    /* Surface & Background */
    --wa-background: #F0F2F5;
    --wa-surface: #FFFFFF;
    --wa-surface-secondary: #F7F8FA;
    --wa-surface-elevated: #FFFFFF;
    
    /* Text Colors */
    --wa-text-primary: #111B21;
    --wa-text-secondary: #667781;
    --wa-text-tertiary: #8696A0;
    --wa-text-on-primary: #FFFFFF;
    
    /* Status Colors */
    --wa-status-online: #00A884;
    --wa-status-typing: #009688;
    --wa-status-offline: #A0A0A0;
    
    /* Message Status */
    --wa-message-sent: #667781;
    --wa-message-delivered: #53BDEB;
    --wa-message-read: #34B7F1;
    
    /* Borders & Dividers */
    --wa-border: #E9EDEF;
    --wa-border-light: #F0F2F5;
    --wa-border-dark: #D1D7DB;
    
    /* Shadows */
    --wa-shadow-sm: 0 1px 3px rgba(11,20,26,0.08);
    --wa-shadow-md: 0 2px 8px rgba(11,20,26,0.12);
    --wa-shadow-lg: 0 4px 16px rgba(11,20,26,0.16);
    --wa-shadow-xl: 0 8px 24px rgba(11,20,26,0.2);
    
    /* Spacing System (8px base) */
    --wa-space-xxs: 4px;
    --wa-space-xs: 8px;
    --wa-space-sm: 12px;
    --wa-space-md: 16px;
    --wa-space-lg: 20px;
    --wa-space-xl: 24px;
    --wa-space-xxl: 32px;
    --wa-space-xxxl: 40px;
    
    /* Typography */
    --wa-font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    --wa-font-size-xs: 12px;
    --wa-font-size-sm: 13px;
    --wa-font-size-md: 14px;
    --wa-font-size-lg: 15px;
    --wa-font-size-xl: 17px;
    --wa-font-size-xxl: 20px;
    --wa-font-weight-normal: 400;
    --wa-font-weight-medium: 500;
    --wa-font-weight-bold: 600;
    
    /* Border Radius */
    --wa-radius-sm: 4px;
    --wa-radius-md: 8px;
    --wa-radius-lg: 12px;
    --wa-radius-xl: 18px;
    --wa-radius-full: 9999px;
    
    /* Transitions */
    --wa-transition-fast: 100ms cubic-bezier(0.4, 0, 0.2, 1);
    --wa-transition-normal: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --wa-transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Z-index layers */
    --wa-z-status-bar: 1000;
    --wa-z-header: 900;
    --wa-z-fab: 800;
    --wa-z-overlay: 700;
    --wa-z-tooltip: 600;
    --wa-z-dropdown: 500;
    --wa-z-default: 1;
    --wa-z-below: -1;
}

/* === BASE RESET & TYPOGRAPHY === */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    font-size: 16px;
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--wa-font-family);
    background-color: var(--wa-background);
    color: var(--wa-text-primary);
    overflow: hidden;
    height: 100vh;
    height: 100dvh;
    user-select: none;
    touch-action: manipulation;
    overscroll-behavior: none;
}

/* === SPLASH SCREEN === */
.splash-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--wa-primary-dark), var(--wa-primary));
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity var(--wa-transition-slow);
}

.splash-content {
    text-align: center;
    animation: splashFadeIn 500ms ease;
}

.splash-logo {
    margin-bottom: var(--wa-space-lg);
    animation: splashPulse 2s infinite;
}

.splash-text {
    color: white;
    font-size: 28px;
    font-weight: var(--wa-font-weight-medium);
    letter-spacing: 0.5px;
    margin-bottom: var(--wa-space-xl);
    opacity: 0.9;
}

.splash-progress {
    width: 120px;
    height: 3px;
    background: rgba(255,255,255,0.2);
    border-radius: var(--wa-radius-full);
    overflow: hidden;
    margin: 0 auto;
}

.splash-progress-bar {
    height: 100%;
    width: 0%;
    background: white;
    animation: splashProgress 1.5s ease-in-out infinite;
}

/* === STATUS BAR (Dynamic Color) === */
.status-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: env(safe-area-inset-top, 0);
    background-color: var(--wa-primary);
    z-index: var(--wa-z-status-bar);
    transition: background-color var(--wa-transition-normal);
}

/* === APP CONTAINER === */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    position: relative;
    padding-top: env(safe-area-inset-top, 0);
    padding-bottom: env(safe-area-inset-bottom, 0);
}

/* === MAIN CONTENT AREA === */
.main-content {
    flex: 1;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
}

.tab-content {
    flex: 1;
    overflow: hidden;
    display: none;
}

.tab-content.active {
    display: block;
    animation: tabFadeIn 200ms ease;
}

/* === PWA INSTALL PROMPT === */
.pwa-prompt {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: var(--wa-z-overlay);
    padding: var(--wa-space-md);
    animation: slideUp 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

.pwa-card {
    background: var(--wa-surface);
    border-radius: var(--wa-radius-lg);
    padding: var(--wa-space-md);
    display: flex;
    align-items: center;
    gap: var(--wa-space-md);
    box-shadow: var(--wa-shadow-lg);
    border: 1px solid var(--wa-border);
    position: relative;
}

.pwa-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.pwa-details {
    flex: 1;
}

.pwa-details h3 {
    font-size: var(--wa-font-size-lg);
    font-weight: var(--wa-font-weight-medium);
    margin-bottom: 2px;
}

.pwa-details p {
    font-size: var(--wa-font-size-sm);
    color: var(--wa-text-secondary);
}

.pwa-actions {
    display: flex;
    gap: var(--wa-space-xs);
    flex-shrink: 0;
}

.pwa-primary, .pwa-secondary {
    padding: var(--wa-space-xs) var(--wa-space-md);
    border-radius: var(--wa-radius-md);
    font-weight: var(--wa-font-weight-medium);
    font-size: var(--wa-font-size-sm);
    border: none;
    cursor: pointer;
    transition: all var(--wa-transition-fast);
}

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

.pwa-primary:hover {
    background: var(--wa-primary-dark);
}

.pwa-secondary {
    background: var(--wa-surface-secondary);
    color: var(--wa-text-secondary);
}

.pwa-secondary:hover {
    background: var(--wa-border);
}

.pwa-close {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 24px;
    height: 24px;
    border: none;
    background: none;
    color: var(--wa-text-tertiary);
    font-size: 18px;
    cursor: pointer;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pwa-close:hover {
    background: var(--wa-border);
}

/* === NETWORK STATUS === */
.network-status {
    position: fixed;
    top: env(safe-area-inset-top, 0);
    left: 0;
    right: 0;
    background: var(--wa-accent-yellow);
    color: #000;
    padding: var(--wa-space-sm) var(--wa-space-md);
    text-align: center;
    z-index: var(--wa-z-header);
    animation: slideDown 200ms ease;
}

.network-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--wa-space-xs);
    font-size: var(--wa-font-size-sm);
    font-weight: var(--wa-font-weight-medium);
}

.network-icon {
    font-size: 16px;
}

/* === SELECTION TOOLBAR (Multi-select) === */
.selection-toolbar {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--wa-surface);
    border-top: 1px solid var(--wa-border);
    padding: var(--wa-space-sm) var(--wa-space-md);
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: var(--wa-z-header);
    animation: slideUp 200ms ease;
    box-shadow: var(--wa-shadow-sm);
}

.selection-count {
    font-size: var(--wa-font-size-md);
    font-weight: var(--wa-font-weight-medium);
    color: var(--wa-text-primary);
}

.selection-actions {
    display: flex;
    gap: var(--wa-space-sm);
}

.selection-btn {
    padding: var(--wa-space-xs) var(--wa-space-sm);
    border: 1px solid var(--wa-border-dark);
    background: var(--wa-surface);
    border-radius: var(--wa-radius-md);
    font-size: var(--wa-font-size-sm);
    color: var(--wa-text-secondary);
    cursor: pointer;
    transition: all var(--wa-transition-fast);
}

.selection-btn:hover {
    background: var(--wa-border-light);
    color: var(--wa-text-primary);
}

.selection-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

/* === FAB & CONTEXT MENU === */
.fab-menu {
    position: fixed;
    bottom: 100px;
    right: var(--wa-space-md);
    background: var(--wa-surface);
    border-radius: var(--wa-radius-lg);
    box-shadow: var(--wa-shadow-lg);
    border: 1px solid var(--wa-border);
    z-index: var(--wa-z-fab);
    overflow: hidden;
    min-width: 200px;
    animation: scaleIn 200ms cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: bottom right;
}

.fab-menu-item {
    display: flex;
    align-items: center;
    gap: var(--wa-space-md);
    width: 100%;
    padding: var(--wa-space-md);
    border: none;
    background: none;
    text-align: left;
    cursor: pointer;
    transition: background-color var(--wa-transition-fast);
    color: var(--wa-text-primary);
    font-size: var(--wa-font-size-md);
}

.fab-menu-item:hover {
    background: var(--wa-border-light);
}

.fab-icon {
    font-size: 20px;
    width: 24px;
    text-align: center;
}

/* === SEARCH OVERLAY === */
.search-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--wa-surface);
    z-index: var(--wa-z-overlay);
    display: flex;
    flex-direction: column;
}

.search-header {
    padding: var(--wa-space-sm) var(--wa-space-md);
    padding-top: calc(var(--wa-space-sm) + env(safe-area-inset-top, 0));
    border-bottom: 1px solid var(--wa-border);
    display: flex;
    align-items: center;
    gap: var(--wa-space-md);
    background: var(--wa-surface);
}

.search-back {
    background: none;
    border: none;
    font-size: 24px;
    color: var(--wa-primary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    flex-shrink: 0;
}

.search-back:hover {
    background: var(--wa-border-light);
}

.search-input-container {
    flex: 1;
    position: relative;
}

.search-input {
    width: 100%;
    padding: var(--wa-space-sm) var(--wa-space-md);
    padding-right: 40px;
    border: 1px solid var(--wa-border-dark);
    border-radius: var(--wa-radius-lg);
    background: var(--wa-surface-secondary);
    font-size: var(--wa-font-size-md);
    color: var(--wa-text-primary);
    outline: none;
    transition: border-color var(--wa-transition-fast);
}

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

.search-clear {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--wa-text-tertiary);
    font-size: 18px;
    cursor: pointer;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.search-clear:hover {
    background: var(--wa-border);
    color: var(--wa-text-secondary);
}

.search-results {
    flex: 1;
    overflow-y: auto;
    padding: var(--wa-space-md);
}

/* === ANIMATIONS === */
@keyframes splashFadeIn {
    from { opacity: 0; transform: scale(0.9); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes splashPulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.05); opacity: 0.9; }
}

@keyframes splashProgress {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(300%); }
}

@keyframes tabFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { transform: translateY(100%); }
    to { transform: translateY(0); }
}

@keyframes slideDown {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

@keyframes scaleIn {
    from { transform: scale(0.8); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

/* === RESPONSIVE BREAKPOINTS === */
@media (min-width: 768px) {
    .app-container {
        flex-direction: row;
        max-width: 1400px;
        margin: 0 auto;
    }
    
    .main-content {
        flex: 1;
        border-left: 1px solid var(--wa-border);
        border-right: 1px solid var(--wa-border);
    }
    
    .pwa-prompt {
        max-width: 400px;
        left: 50%;
        transform: translateX(-50%);
        bottom: var(--wa-space-xl);
    }
    
    .selection-toolbar {
        max-width: 400px;
        left: 50%;
        transform: translateX(-50%);
        bottom: var(--wa-space-xl);
        border-radius: var(--wa-radius-lg);
        border: 1px solid var(--wa-border);
    }
}

@media (min-width: 1024px) {
    :root {
        --wa-space-md: 20px;
        --wa-space-lg: 24px;
        --wa-space-xl: 32px;
    }
    
    .main-content {
        max-width: 800px;
        margin: 0 auto;
    }
}

/* === UTILITY CLASSES === */
.hidden { display: none !important; }
.flex { display: flex; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.flex-col { flex-direction: column; }
.gap-xs { gap: var(--wa-space-xs); }
.gap-sm { gap: var(--wa-space-sm); }
.gap-md { gap: var(--wa-space-md); }
.p-sm { padding: var(--wa-space-sm); }
.p-md { padding: var(--wa-space-md); }
.p-lg { padding: var(--wa-space-lg); }
.mt-sm { margin-top: var(--wa-space-sm); }
.mt-md { margin-top: var(--wa-space-md); }
.text-sm { font-size: var(--wa-font-size-sm); }
.text-md { font-size: var(--wa-font-size-md); }
.text-secondary { color: var(--wa-text-secondary); }
.text-tertiary { color: var(--wa-text-tertiary); }
.bg-surface { background: var(--wa-surface); }
.bg-secondary { background: var(--wa-surface-secondary); }
.rounded-sm { border-radius: var(--wa-radius-sm); }
.rounded-md { border-radius: var(--wa-radius-md); }
.rounded-lg { border-radius: var(--wa-radius-lg); }
.shadow-sm { box-shadow: var(--wa-shadow-sm); }
.shadow-md { box-shadow: var(--wa-shadow-md); }
.full-width { width: 100%; }
.full-height { height: 100%; }
.pointer { cursor: pointer; }
.select-none { user-select: none; }
.truncate {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* === SCROLLBAR STYLING === */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--wa-border-dark);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--wa-text-tertiary);
}

/* === PRINT STYLES === */
@media print {
    .app-container,
    .splash-screen,
    .pwa-prompt,
    .network-status,
    .selection-toolbar,
    .fab-menu,
    .search-overlay {
        display: none !important;
    }
    
    body {
        overflow: auto;
        height: auto;
    }
}