/* ===================================
   Design System & CSS Variables
   =================================== */

:root {
    /* Professional Technical Color Palette */
    --color-primary: hsl(195, 85%, 50%);
    --color-primary-hover: hsl(195, 85%, 45%);
    --color-primary-light: hsl(195, 85%, 60%);
    --color-secondary: hsl(180, 70%, 45%);
    --color-accent: hsl(170, 75%, 50%);
    
    /* Dark Theme Base */
    --color-bg-primary: hsl(220, 20%, 10%);
    --color-bg-secondary: hsl(220, 18%, 14%);
    --color-bg-tertiary: hsl(220, 16%, 18%);
    --color-bg-elevated: hsl(220, 18%, 20%);
    
    /* Text Colors */
    --color-text-primary: hsl(0, 0%, 98%);
    --color-text-secondary: hsl(0, 0%, 75%);
    --color-text-tertiary: hsl(0, 0%, 60%);
    
    /* Border & Divider */
    --color-border: hsl(220, 15%, 25%);
    --color-border-light: hsl(220, 15%, 30%);
    
    /* Status Colors */
    --color-success: hsl(142, 70%, 50%);
    --color-warning: hsl(45, 90%, 55%);
    --color-error: hsl(0, 70%, 55%);
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 20px rgba(52, 211, 243, 0.3);
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    
    /* Panel Width */
    --panel-width: 380px;
    --header-height: 60px;
}

/* ===================================
   Base Styles
   =================================== */

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

body {
    font-family: var(--font-family);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow: hidden;
    height: 100vh;
}

/* ===================================
   Header
   =================================== */

.header {
    height: var(--header-height);
    background: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    position: relative;
    z-index: 1000;
}

.header-content {
    height: 100%;
    padding: 0 var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary);
}

.logo i {
    font-size: 1.75rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.header-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.btn-icon {
    width: 40px;
    height: 40px;
    border: none;
    background: var(--color-bg-tertiary);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-lg);
}

.btn-icon:hover {
    background: var(--color-bg-elevated);
    color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===================================
   Main Layout
   =================================== */

.main-container {
    display: flex;
    height: calc(100vh - var(--header-height));
    overflow: hidden;
}

/* ===================================
   Control Panel
   =================================== */

.control-panel {
    width: var(--panel-width);
    background: var(--color-bg-secondary);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
    overflow-x: hidden;
}

/* Custom Scrollbar */
.control-panel::-webkit-scrollbar {
    width: 8px;
}

.control-panel::-webkit-scrollbar-track {
    background: var(--color-bg-secondary);
}

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

.control-panel::-webkit-scrollbar-thumb:hover {
    background: var(--color-border-light);
}

.panel-section {
    border-bottom: 1px solid var(--color-border);
    animation: slideInLeft 0.4s ease;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.panel-title {
    padding: var(--spacing-lg);
    font-size: var(--font-size-lg);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-bg-tertiary);
    color: var(--color-primary-light);
}

.panel-content {
    padding: var(--spacing-lg);
}

.help-text {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-tertiary);
    border-left: 3px solid var(--color-primary);
    border-radius: var(--radius-sm);
}

/* ===================================
   Form Elements
   =================================== */

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.input-field {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    transition: all var(--transition-fast);
}

.input-field:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(52, 211, 243, 0.1);
}

.input-field::placeholder {
    color: var(--color-text-tertiary);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--color-primary);
}

.checkbox-group label {
    margin: 0;
    cursor: pointer;
}

/* ===================================
   Buttons
   =================================== */

.btn-primary {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

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

/* ===================================
   Item Lists
   =================================== */

.item-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-height: 250px;
    overflow-y: auto;
}

.item-list:empty::before {
    content: 'No items yet';
    display: block;
    text-align: center;
    color: var(--color-text-tertiary);
    font-size: var(--font-size-sm);
    padding: var(--spacing-lg);
}

.item-card {
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    transition: all var(--transition-fast);
    animation: slideIn 0.3s ease;
}

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

.item-card:hover {
    background: var(--color-bg-elevated);
    border-color: var(--color-primary);
    transform: translateX(4px);
}

.item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.item-name {
    font-weight: 600;
    color: var(--color-text-primary);
}

.item-actions {
    display: flex;
    gap: var(--spacing-xs);
}

.btn-small {
    padding: 4px 8px;
    background: var(--color-bg-secondary);
    border: none;
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    cursor: pointer;
    font-size: var(--font-size-xs);
    transition: all var(--transition-fast);
}

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

.btn-small.delete:hover {
    background: var(--color-error);
}

.item-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.frequency-badge {
    display: inline-block;
    padding: 2px 8px;
    background: var(--color-primary);
    color: white;
    border-radius: 12px;
    font-size: var(--font-size-xs);
    font-weight: 600;
}

/* ===================================
   Map Container
   =================================== */

.map-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

#map {
    width: 100%;
    height: 100%;
}

/* ===================================
   Map Overlays
   =================================== */

.map-overlay {
    position: absolute;
    z-index: 1000;
    pointer-events: none;
}

.map-overlay > * {
    pointer-events: auto;
}

.map-overlay.top-left {
    top: var(--spacing-lg);
    left: var(--spacing-lg);
}

.stats-card {
    background: rgba(20, 25, 35, 0.95);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    display: flex;
    gap: var(--spacing-xl);
    animation: fadeInDown 0.5s ease;
}

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

.stat-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.stat-item i {
    font-size: 2rem;
    color: var(--color-primary);
}

.stat-value {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-primary-light);
    line-height: 1;
}

.stat-label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

/* ===================================
   Link Info Panel
   =================================== */

.link-info-panel {
    position: absolute;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 350px;
    background: rgba(20, 25, 35, 0.98);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    animation: slideInUp 0.4s ease;
    overflow: hidden;
}

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

.link-info-panel.hidden {
    display: none;
}

.link-info-header {
    padding: var(--spacing-lg);
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.link-info-header h3 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-primary-light);
}

.btn-close {
    background: none;
    border: none;
    color: var(--color-text-secondary);
    font-size: var(--font-size-lg);
    cursor: pointer;
    padding: var(--spacing-xs);
    transition: all var(--transition-fast);
}

.btn-close:hover {
    color: var(--color-primary);
    transform: rotate(90deg);
}

.link-info-content {
    padding: var(--spacing-lg);
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
}

.info-row:last-child {
    border-bottom: none;
}

.info-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    font-weight: 500;
}

.info-value {
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
    font-weight: 600;
}

/* ===================================
   Leaflet Custom Styles
   =================================== */

.leaflet-popup-content-wrapper {
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
}

.leaflet-popup-content {
    margin: var(--spacing-md);
    font-family: var(--font-family);
}

.leaflet-popup-tip {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
}

.leaflet-container a.leaflet-popup-close-button {
    color: var(--color-text-secondary);
}

.leaflet-container a.leaflet-popup-close-button:hover {
    color: var(--color-primary);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 1024px) {
    :root {
        --panel-width: 320px;
    }
    
    .stats-card {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .control-panel {
        position: absolute;
        left: -100%;
        height: 100%;
        z-index: 2000;
        transition: left var(--transition-normal);
    }
    
    .control-panel.active {
        left: 0;
    }
    
    .link-info-panel {
        width: calc(100% - 2 * var(--spacing-lg));
        max-width: 350px;
    }
}

/* ===================================
   Utility Classes
   =================================== */

.hidden {
    display: none !important;
}

.fade-in {
    animation: fadeIn 0.3s ease;
}

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