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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --danger-color: #ff6b6b;
    --success-color: #51cf66;
    --warning-color: #ffd43b;
    --info-color: #4ecdc4;
    --dark-color: #2c3e50;
    --light-color: #f8f9fa;
    --border-color: #dee2e6;
    --text-color: #333;
    --text-muted: #6c757d;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
}

.nav {
    display: flex;
    gap: 20px;
}

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link:hover,
.nav-link.active {
    background: var(--primary-color);
    color: white;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    min-height: calc(100vh - 70px);
}

.page {
    display: none;
    animation: fadeIn 0.5s ease;
}

.page.active {
    display: block;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.9), rgba(118, 75, 162, 0.9));
    color: white;
    padding: 100px 0;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 40px;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    font-weight: 600;
}

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

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
}

.btn-secondary:hover {
    background: var(--light-color);
    transform: translateY(-2px);
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #ff5252;
    transform: translateY(-2px);
}

.btn-info {
    background: var(--info-color);
    color: white;
}

.btn-info:hover {
    background: #3db9b0;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* Features Section */
.features {
    padding: 80px 0;
    background: white;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--dark-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.feature-card p {
    color: var(--text-muted);
    line-height: 1.8;
}

/* Auth Container */
.auth-container {
    max-width: 500px;
    margin: 50px auto;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.auth-tabs {
    display: flex;
}

.auth-tab {
    flex: 1;
    padding: 15px;
    background: var(--light-color);
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.auth-tab.active {
    background: white;
    color: var(--primary-color);
}

.auth-form {
    display: none;
    padding: 40px;
}

.auth-form.active {
    display: block;
}

.auth-form h2 {
    margin-bottom: 30px;
    color: var(--dark-color);
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--dark-color);
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Dashboard */
.dashboard-header {
    background: white;
    padding: 30px;
    border-radius: 12px;
    margin: 30px 0;
    box-shadow: var(--shadow);
}

.dashboard-header h1 {
    color: var(--dark-color);
    margin-bottom: 10px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 20px;
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: white;
}

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--dark-color);
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.action-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.device-info,
.alerts-section {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    margin-bottom: 30px;
}

.device-info h3,
.alerts-section h3 {
    margin-bottom: 20px;
    color: var(--dark-color);
}

.alerts-list {
    max-height: 500px;
    overflow-y: auto;
}

.alert-item {
    background: var(--light-color);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 15px;
    border-left: 4px solid var(--primary-color);
    cursor: pointer;
    transition: all 0.3s ease;
}

.alert-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.alert-item.high {
    border-left-color: var(--danger-color);
}

.alert-item.medium {
    border-left-color: var(--warning-color);
}

.alert-item.low {
    border-left-color: var(--info-color);
}

.alert-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.alert-type {
    font-weight: bold;
    color: var(--dark-color);
}

.alert-time {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.alert-badge {
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
    color: white;
}

.badge-high {
    background: var(--danger-color);
}

.badge-medium {
    background: var(--warning-color);
}

.badge-low {
    background: var(--info-color);
}

/* Filters */
.filters {
    background: white;
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 30px;
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    box-shadow: var(--shadow);
}

.filter-select {
    padding: 10px 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s ease;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    padding: 40px;
    border-radius: 12px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    animation: slideUp 0.3s ease;
}

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

.close {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--text-muted);
    transition: color 0.3s ease;
}

.close:hover {
    color: var(--danger-color);
}

.qr-container {
    text-align: center;
    padding: 30px;
    background: var(--light-color);
    border-radius: 12px;
    margin: 20px 0;
}

.qr-container img {
    max-width: 100%;
    height: auto;
}

.qr-instruction {
    text-align: center;
    color: var(--text-muted);
    margin: 20px 0;
}

/* Camera View */
.camera-view {
    position: relative;
    background: black;
    border-radius: 12px;
    overflow: hidden;
    margin: 20px 0;
}

#qrVideo {
    width: 100%;
    height: auto;
    display: block;
}

.camera-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.scan-frame {
    width: 250px;
    height: 250px;
    border: 3px solid var(--success-color);
    border-radius: 12px;
    box-shadow: 0 0 0 9999px rgba(0, 0, 0, 0.5);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        border-color: var(--success-color);
    }
    50% {
        border-color: var(--warning-color);
    }
}

.upload-section {
    text-align: center;
    padding: 20px;
}

.file-input {
    display: none;
}

.scan-result {
    text-align: center;
    padding: 20px;
    background: var(--success-color);
    color: white;
    border-radius: 8px;
    margin-top: 20px;
}

.scan-result.hidden {
    display: none;
}

.scan-result i {
    font-size: 3rem;
    margin-bottom: 10px;
}

/* Toast */
.toast-container {
    position: fixed;
    top: 80px;
    right: 20px;
    z-index: 3000;
}

.toast {
    background: white;
    padding: 15px 20px;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 15px;
    min-width: 300px;
    animation: slideInRight 0.3s ease;
}

@keyframes slideInRight {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--danger-color);
}

.toast.warning {
    border-left: 4px solid var(--warning-color);
}

.toast.info {
    border-left: 4px solid var(--info-color);
}

.toast i {
    font-size: 1.5rem;
}

.toast.success i {
    color: var(--success-color);
}

.toast.error i {
    color: var(--danger-color);
}

.toast.warning i {
    color: var(--warning-color);
}

.toast.info i {
    color: var(--info-color);
}

/* Loading Spinner */
.loading-spinner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 4000;
}

.loading-spinner.hidden {
    display: none;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 5px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Utilities */
.hidden {
    display: none !important;
}

.text-muted {
    color: var(--text-muted);
}

.text-center {
    text-align: center;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .menu-toggle {
        display: block;
    }

    .nav {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 250px;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: var(--shadow-lg);
        transition: left 0.3s ease;
    }

    .nav.active {
        left: 0;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .filters {
        flex-direction: column;
    }

    .modal-content {
        width: 95%;
        padding: 20px;
    }

    .toast {
        min-width: auto;
        width: calc(100vw - 40px);
    }

    .toast-container {
        right: 10px;
        left: 10px;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 60px 0;
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }

    .features {
        padding: 40px 0;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }
}