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

:root {
    --primary-color: #00BCD4;
    --secondary-color: #4CAF50;
    --accent-color: #FF4081;
    --dark-bg: #121212;
    --card-bg: #1E1E1E;
    --text-primary: #FFFFFF;
    --text-secondary: #B0B0B0;
    --online-color: #4CAF50;
    --offline-color: #757575;
    --border-color: #2C2C2C;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--dark-bg);
    color: var(--text-primary);
    overflow-x: hidden;
}

.screen {
    display: none;
    min-height: 100vh;
    background: var(--dark-bg);
}

.screen.active {
    display: block;
}

/* Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    background: rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
}

.time {
    font-size: 14px;
    font-weight: 600;
}

.status-icons {
    display: flex;
    gap: 8px;
}

.status-icon {
    width: 16px;
    height: 16px;
}

/* App Header */
.app-header {
    display: flex;
    justify-content: space-between;
    padding: 16px 20px;
}

.back-btn, .menu-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.3s;
}

.back-btn:hover, .menu-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* App Info */
.app-info {
    display: flex;
    gap: 20px;
    padding: 0 20px 20px;
    align-items: center;
}

.app-icon {
    flex-shrink: 0;
}

.icon-circle {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 24px rgba(0, 188, 212, 0.3);
}

.icon-circle i {
    width: 40px;
    height: 40px;
    color: white;
}

.app-details h1 {
    font-size: 22px;
    margin-bottom: 8px;
    line-height: 1.3;
}

.developer {
    color: var(--primary-color);
    font-size: 14px;
    margin-bottom: 4px;
}

.purchase-info {
    color: var(--text-secondary);
    font-size: 13px;
}

/* App Stats */
.app-stats {
    display: flex;
    justify-content: space-around;
    padding: 20px;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    margin: 0 20px;
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

.stat-badge {
    background: var(--card-bg);
    padding: 4px 12px;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 4px;
}

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

/* Install Button */
.install-btn {
    background: linear-gradient(135deg, #A8D5FF, #7AB8FF);
    color: #000;
    border: none;
    padding: 16px;
    margin: 20px;
    border-radius: 30px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    width: calc(100% - 40px);
    transition: transform 0.2s, box-shadow 0.3s;
}

.install-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(168, 213, 255, 0.4);
}

/* Screenshots */
.screenshots {
    display: flex;
    gap: 16px;
    padding: 20px;
    overflow-x: auto;
    scrollbar-width: none;
}

.screenshots::-webkit-scrollbar {
    display: none;
}

.screenshot-card {
    min-width: 200px;
    height: 300px;
    border-radius: 16px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    position: relative;
    overflow: hidden;
}

.screenshot-card.cyan {
    background: linear-gradient(135deg, #00BCD4, #00ACC1);
}

.screenshot-card.green {
    background: linear-gradient(135deg, #4CAF50, #45A049);
}

.screenshot-card.pink {
    background: linear-gradient(135deg, #FF4081, #F50057);
}

.screenshot-content h3 {
    font-size: 16px;
    line-height: 1.4;
    margin-bottom: 20px;
}

.screenshot-preview {
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    padding: 40px;
    backdrop-filter: blur(10px);
}

.screenshot-preview i {
    width: 60px;
    height: 60px;
}

/* About Section */
.about-section {
    padding: 20px;
}

.about-section h2 {
    font-size: 20px;
    margin-bottom: 12px;
}

.about-section p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.badge {
    display: inline-block;
    background: var(--card-bg);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    border: 1px solid var(--border-color);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-around;
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 12px 0;
}

.nav-item {
    background: none;
    border: none;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    cursor: pointer;
    padding: 8px 16px;
    transition: color 0.3s;
}

.nav-item i {
    width: 24px;
    height: 24px;
}

.nav-item span {
    font-size: 11px;
}

.nav-item.active {
    color: var(--primary-color);
}

/* Main App Screen */
.app-container {
    max-width: 600px;
    margin: 0 auto;
    min-height: 100vh;
    background: var(--dark-bg);
}

.app-top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
}

.menu-icon, .settings-icon {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.3s;
}

.menu-icon:hover, .settings-icon:hover {
    background: rgba(255, 255, 255, 0.1);
}

.app-top-bar h2 {
    font-size: 18px;
}

/* Tabs */
.tabs {
    display: flex;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
}

.tab {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    border-bottom: 2px solid transparent;
    transition: all 0.3s;
    white-space: nowrap;
}

.tab i {
    width: 20px;
    height: 20px;
}

.tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
    padding: 20px;
    animation: fadeIn 0.3s;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Search Bar */
.search-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--card-bg);
    padding: 12px 16px;
    border-radius: 12px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

.search-bar i {
    width: 20px;
    height: 20px;
    color: var(--text-secondary);
}

.search-bar input {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 15px;
    outline: none;
}

.search-bar input::placeholder {
    color: var(--text-secondary);
}

/* Contact List */
.contact-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--card-bg);
    padding: 16px;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s;
    border: 1px solid var(--border-color);
    position: relative;
}

.contact-item:hover {
    background: rgba(255, 255, 255, 0.05);
    transform: translateX(4px);
}

.delete-contact-btn {
    background: rgba(255, 64, 129, 0.1);
    border: 1px solid rgba(255, 64, 129, 0.3);
    color: var(--accent-color);
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    margin-left: auto;
}

.delete-contact-btn:hover {
    background: var(--accent-color);
    color: white;
    transform: scale(1.1);
}

.delete-contact-btn i {
    width: 18px;
    height: 18px;
}

.contact-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 600;
    position: relative;
    flex-shrink: 0;
}

.status-indicator {
    position: absolute;
    bottom: 2px;
    right: 2px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 2px solid var(--card-bg);
}

.status-indicator.online {
    background: var(--online-color);
    box-shadow: 0 0 8px var(--online-color);
}

.status-indicator.offline {
    background: var(--offline-color);
}

.contact-info {
    flex: 1;
}

.contact-name {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 4px;
}

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

.contact-status i {
    width: 14px;
    height: 14px;
}

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

/* Activity List */
.activity-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.activity-header h3 {
    font-size: 18px;
}

.filter-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 16px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.3s;
}

.filter-btn:hover {
    background: rgba(255, 255, 255, 0.05);
}

.filter-btn i {
    width: 16px;
    height: 16px;
}

.activity-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.activity-item {
    background: var(--card-bg);
    padding: 16px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 16px;
}

.activity-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.activity-icon.online {
    background: rgba(76, 175, 80, 0.2);
    color: var(--online-color);
}

.activity-icon.offline {
    background: rgba(117, 117, 117, 0.2);
    color: var(--offline-color);
}

.activity-icon i {
    width: 20px;
    height: 20px;
}

.activity-details {
    flex: 1;
}

.activity-text {
    font-size: 14px;
    margin-bottom: 4px;
}

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

/* Notification Settings */
.notification-settings h3 {
    font-size: 18px;
    margin-bottom: 20px;
}

.setting-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--card-bg);
    padding: 16px;
    border-radius: 12px;
    margin-bottom: 12px;
    border: 1px solid var(--border-color);
}

.setting-info {
    display: flex;
    align-items: center;
    gap: 16px;
    flex: 1;
}

.setting-info i {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
}

.setting-info h4 {
    font-size: 15px;
    margin-bottom: 4px;
}

.setting-info p {
    font-size: 13px;
    color: var(--text-secondary);
}

/* Toggle Switch */
.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 28px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: 0.4s;
    border-radius: 28px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: 0.4s;
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(22px);
}

/* FAB Button */
.fab {
    position: fixed;
    bottom: 80px;
    right: 20px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border: none;
    color: white;
    cursor: pointer;
    box-shadow: 0 4px 16px rgba(0, 188, 212, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    z-index: 100;
}

.fab:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 24px rgba(0, 188, 212, 0.6);
}

.fab i {
    width: 24px;
    height: 24px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(4px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--card-bg);
    border-radius: 16px;
    width: 90%;
    max-width: 400px;
    border: 1px solid var(--border-color);
    animation: slideUp 0.3s;
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

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

.close-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 4px;
    border-radius: 50%;
    transition: background 0.3s;
}

.close-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.close-btn i {
    width: 24px;
    height: 24px;
}

.modal-body {
    padding: 20px;
}

.input-group {
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    font-size: 14px;
    margin-bottom: 8px;
    color: var(--text-secondary);
}

.input-group input {
    width: 100%;
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 15px;
    outline: none;
    transition: border-color 0.3s;
}

.input-group input:focus {
    border-color: var(--primary-color);
}

.add-btn {
    width: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 14px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s;
}

.add-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 188, 212, 0.4);
}

.add-btn i {
    width: 20px;
    height: 20px;
}

/* Responsive Design */
@media (max-width: 480px) {
    .app-info {
        flex-direction: column;
        text-align: center;
    }

    .app-stats {
        flex-wrap: wrap;
        gap: 16px;
    }

    .stat {
        flex: 1 1 30%;
    }

    .screenshots {
        padding: 20px 10px;
    }

    .screenshot-card {
        min-width: 180px;
        height: 280px;
    }
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.loading {
    animation: pulse 1.5s ease-in-out infinite;
}