:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --accent-color: #4895ef;
    --dark-color: #1a1a2e;
    --light-color: #f8f9fa;
    --success-color: #4cc9f0;
    --warning-color: #f8961e;
    --danger-color: #f72585;
    --card-bg: rgba(255, 255, 255, 0.9);
    --border-radius: 12px;
    --box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    color: #333;
    transition: background 0.3s ease;
}

/* Landing Page Styles */
.landing-page {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    text-align: center;
    padding: 2rem;
}

.landing-content {
    max-width: 600px;
    animation: fadeIn 0.8s ease;
}

h1 {
    font-size: 3rem;
    color: var(--dark-color);
    margin-bottom: 1rem;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.subtitle {
    color: var(--secondary-color);
    font-weight: 500;
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.btn-start {
    display: inline-flex;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 6px 15px rgba(67, 97, 238, 0.3);
    margin-top: 1.5rem;
}

.btn-start:hover {
    background: var(--secondary-color);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(67, 97, 238, 0.4);
}

.btn-start:active {
    transform: translateY(0);
}

.btn-start i {
    margin-right: 0.75rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 3rem;
    width: 100%;
}

.feature-item {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-title {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.feature-desc {
    color: #666;
    font-size: 0.9rem;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s ease;
}

.loading-screen.active {
    opacity: 1;
    pointer-events: all;
}

.loader {
    width: 60px;
    height: 60px;
    border: 5px solid rgba(67, 97, 238, 0.2);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s linear infinite;
    margin-bottom: 1.5rem;
}

.loading-text {
    font-size: 1.2rem;
    color: var(--dark-color);
    margin-top: 1rem;
    text-align: center;
}

.loading-progress {
    width: 200px;
    height: 6px;
    background: rgba(67, 97, 238, 0.1);
    border-radius: 3px;
    margin-top: 1rem;
    overflow: hidden;
}

.loading-progress-bar {
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
    border-radius: 3px;
}

/* Main App Styles (hidden initially) */
.app-container {
    display: none;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

.card-header {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.card-header i {
    font-size: 1.5rem;
    margin-right: 0.75rem;
    color: var(--primary-color);
}

.card-header h2 {
    font-size: 1.25rem;
    color: var(--dark-color);
}

.info-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.75rem;
    padding: 0.5rem 0;
    border-bottom: 1px dashed rgba(0, 0, 0, 0.05);
}

.info-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.info-label {
    font-weight: 600;
    color: var(--secondary-color);
}

.info-value {
    font-weight: 500;
    color: var(--dark-color);
}

.progress-container {
    margin-top: 1rem;
}

.progress-bar {
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    border-radius: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.5s ease;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: #6c757d;
}

.battery-container {
    display: flex;
    align-items: center;
    margin-top: 1rem;
}

.battery {
    width: 60px;
    height: 30px;
    border: 2px solid #333;
    border-radius: 4px;
    position: relative;
    margin-right: 1rem;
}

.battery::after {
    content: '';
    position: absolute;
    right: -8px;
    top: 8px;
    width: 4px;
    height: 10px;
    background: #333;
    border-radius: 0 2px 2px 0;
}

.battery-level {
    height: 100%;
    background: var(--success-color);
    border-radius: 2px;
}

.network-status {
    display: flex;
    align-items: center;
    margin-top: 1rem;
}

.network-icon {
    font-size: 1.5rem;
    margin-right: 0.75rem;
    color: var(--success-color);
}

.network-info {
    flex-grow: 1;
}

.btn-refresh {
    display: block;
    margin: 2rem auto 0;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.btn-refresh:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.btn-refresh:active {
    transform: translateY(0);
}

.btn-refresh i {
    margin-right: 0.5rem;
}

.dark-mode-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--dark-color);
    color: white;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    z-index: 100;
}

/* Dark mode styles */
body.dark-mode {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #f8f9fa;
}

body.dark-mode .landing-page {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

body.dark-mode h1 {
    background: linear-gradient(90deg, #4895ef, #4cc9f0);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

body.dark-mode .subtitle {
    color: var(--accent-color);
}

body.dark-mode .feature-item {
    background: rgba(30, 30, 46, 0.9);
}

body.dark-mode .feature-title {
    color: #f8f9fa;
}

body.dark-mode .feature-desc {
    color: #aaa;
}

body.dark-mode .card {
    background: rgba(30, 30, 46, 0.9);
    color: #f8f9fa;
}

body.dark-mode .card-header h2 {
    color: #f8f9fa;
}

body.dark-mode .info-label {
    color: var(--accent-color);
}

body.dark-mode .info-value {
    color: #f8f9fa;
}

body.dark-mode .card-header {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

body.dark-mode .info-item {
    border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.pulse {
    animation: pulse 2s infinite;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    h1 {
        font-size: 2.2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
    
    .dashboard {
        grid-template-columns: 1fr;
    }
}