/* =====================================================
   TunnelVision - CSS Design System
   Interactive Web Request Journey Visualizer
   ===================================================== */

/* =====================================================
   CSS Custom Properties (Design Tokens)
   ===================================================== */
:root {
    /* Colors - Dark Theme (Default) */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-elevated: #222230;

    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #606070;

    /* Accent Colors */
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-success: #10b981;
    --accent-warning: #f59e0b;
    --accent-error: #ef4444;
    --accent-info: #3b82f6;

    /* OSI Layer Colors */
    --layer-7-application: #a855f7;
    --layer-6-presentation: #eab308;
    --layer-5-session: #f59e0b;
    --layer-4-transport: #3b82f6;
    --layer-3-network: #22c55e;
    --layer-2-datalink: #f97316;
    --layer-1-physical: #ef4444;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
    --gradient-dark: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    --gradient-glow: radial-gradient(circle at center, rgba(99, 102, 241, 0.15) 0%, transparent 70%);

    /* Glass Effect */
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glass-blur: 20px;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.3);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
    --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Layout */
    --header-height: 60px;
    --sidebar-width: 200px;
    --timeline-height: 100px;
}

/* Light Theme */
[data-theme="light"] {
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-tertiary: #e2e8f0;
    --bg-elevated: #ffffff;

    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;

    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(0, 0, 0, 0.1);

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
}

/* =====================================================
   Reset & Base Styles
   ===================================================== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

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

/* =====================================================
   Loading Screen
   ===================================================== */
.loading-screen {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader {
    text-align: center;
}

.loader-packet {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--space-4);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    animation: packetPulse 1.5s ease-in-out infinite;
    box-shadow: var(--shadow-glow);
}

.loader-text {
    color: var(--text-secondary);
    font-size: var(--text-sm);
    letter-spacing: 0.5px;
    animation: textFade 1.5s ease-in-out infinite;
}

@keyframes packetPulse {

    0%,
    100% {
        transform: scale(1) rotate(0deg);
        opacity: 1;
    }

    50% {
        transform: scale(1.1) rotate(180deg);
        opacity: 0.8;
    }
}

@keyframes textFade {

    0%,
    100% {
        opacity: 0.5;
    }

    50% {
        opacity: 1;
    }
}

/* =====================================================
   Main App Container
   ===================================================== */
.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    opacity: 1;
    transition: opacity var(--transition-base);
}

.app.hidden {
    opacity: 0;
}

/* =====================================================
   Header
   ===================================================== */
.header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--space-6);
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border-bottom: 1px solid var(--glass-border);
    z-index: 100;
}

.header-left,
.header-right {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.logo-icon {
    font-size: var(--text-2xl);
}

.logo-text {
    font-size: var(--text-xl);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.url-display {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    padding: var(--space-2) var(--space-4);
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    border: 1px solid var(--glass-border);
}

.url-scheme {
    color: var(--accent-success);
}

.url-host {
    color: var(--accent-info);
    font-weight: 600;
}

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

/* =====================================================
   Buttons
   ===================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-2) var(--space-4);
    font-family: var(--font-primary);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--text-primary);
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn:hover {
    background: var(--bg-elevated);
    border-color: var(--accent-primary);
    transform: translateY(-1px);
}

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

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: var(--radius-md);
}

.btn-play {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    background: var(--gradient-primary);
    border: none;
    box-shadow: var(--shadow-glow);
    color: white;
}

.btn-play:hover {
    transform: scale(1.1);
    box-shadow: 0 0 40px rgba(99, 102, 241, 0.5);
}

.btn-control {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
}

.btn-close {
    font-size: var(--text-xl);
    font-weight: 300;
}

/* =====================================================
   Main Content Layout
   ===================================================== */
.main-content {
    flex: 1;
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr var(--sidebar-width);
    gap: var(--space-4);
    padding: var(--space-4);
    overflow: hidden;
}

/* =====================================================
   OSI Layer Sidebar
   ===================================================== */
.osi-sidebar {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    overflow-y: auto;
}

.sidebar-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--space-4);
}

.osi-layers {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.osi-layer {
    display: flex;
    flex-direction: column;
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    border-left: 3px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.osi-layer:hover {
    background: var(--bg-elevated);
    transform: translateX(4px);
}

.osi-layer.active {
    background: var(--bg-elevated);
    box-shadow: var(--shadow-md);
}

.osi-layer[data-layer="7"] {
    border-left-color: var(--layer-7-application);
}

.osi-layer[data-layer="6"] {
    border-left-color: var(--layer-6-presentation);
}

.osi-layer[data-layer="5"] {
    border-left-color: var(--layer-5-session);
}

.osi-layer[data-layer="4"] {
    border-left-color: var(--layer-4-transport);
}

.osi-layer[data-layer="3"] {
    border-left-color: var(--layer-3-network);
}

.osi-layer[data-layer="2"] {
    border-left-color: var(--layer-2-datalink);
}

.osi-layer[data-layer="1"] {
    border-left-color: var(--layer-1-physical);
}

.layer-num {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--text-muted);
}

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

.layer-protocols {
    font-size: var(--text-xs);
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

/* =====================================================
   Visualization Container
   ===================================================== */
.visualization-container {
    position: relative;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    overflow: hidden;
}

.visualization-container::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-glow);
    pointer-events: none;
}

/* =====================================================
   Network Topology
   ===================================================== */
.network-topology {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-around;
    padding: var(--space-8);
}

.network-node {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-4);
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-base);
    z-index: 10;
}

.network-node:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-glow);
    border-color: var(--accent-primary);
}

.network-node.active {
    border-color: var(--accent-primary);
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.4);
    animation: nodeGlow 2s ease-in-out infinite;
}

@keyframes nodeGlow {

    0%,
    100% {
        box-shadow: 0 0 20px rgba(99, 102, 241, 0.3);
    }

    50% {
        box-shadow: 0 0 40px rgba(99, 102, 241, 0.5);
    }
}

.node-icon {
    font-size: 2.5rem;
    line-height: 1;
}

.node-label {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
}

.node-ip {
    font-size: var(--text-xs);
    font-family: var(--font-mono);
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
}

/* Connection Lines */
.connection-line {
    position: absolute;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0.3;
    z-index: 1;
}

.connection-line.active {
    opacity: 1;
    animation: lineFlow 1s linear infinite;
}

@keyframes lineFlow {
    0% {
        background-position: 0% 50%;
    }

    100% {
        background-position: 100% 50%;
    }
}

/* Packet Container */
.packet-container {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 20;
}

.packet {
    position: absolute;
    width: 24px;
    height: 24px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-xs);
    font-weight: 700;
    color: white;
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-fast);
}

.packet.http {
    background: var(--layer-7-application);
}

.packet.tls {
    background: var(--layer-6-presentation);
}

.packet.tcp {
    background: var(--layer-4-transport);
}

.packet.ip {
    background: var(--layer-3-network);
}

.packet.ethernet {
    background: var(--layer-2-datalink);
}

.packet.physical {
    background: var(--layer-1-physical);
}

/* =====================================================
   Phase Info Panel
   ===================================================== */
.phase-info-panel {
    position: absolute;
    bottom: var(--space-4);
    left: var(--space-4);
    right: var(--space-4);
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    max-height: 200px;
    overflow-y: auto;
}

.phase-header {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-3);
}

.phase-number {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--accent-primary);
    background: rgba(99, 102, 241, 0.2);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
}

.phase-title {
    font-size: var(--text-lg);
    font-weight: 700;
}

.phase-description {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.7;
}

/* =====================================================
   Packet Inspector
   ===================================================== */
.packet-inspector {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    width: 320px;
    background: var(--bg-elevated);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.inspector-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-3) var(--space-4);
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--glass-border);
}

.inspector-title {
    font-size: var(--text-sm);
    font-weight: 600;
}

.inspector-layers {
    padding: var(--space-4);
    max-height: 400px;
    overflow-y: auto;
}

.inspector-layer {
    margin-bottom: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--accent-primary);
}

.inspector-layer-name {
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.inspector-field {
    display: flex;
    justify-content: space-between;
    font-size: var(--text-xs);
    padding: var(--space-1) 0;
    border-bottom: 1px solid var(--glass-border);
}

.inspector-field:last-child {
    border-bottom: none;
}

.field-label {
    color: var(--text-secondary);
}

.field-value {
    font-family: var(--font-mono);
    color: var(--text-primary);
}

/* =====================================================
   Info Sidebar
   ===================================================== */
.info-sidebar {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.sidebar-tabs {
    display: flex;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--glass-border);
}

.tab-btn {
    flex: 1;
    padding: var(--space-3);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-secondary);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    color: var(--text-primary);
    background: var(--bg-elevated);
}

.tab-btn.active {
    color: var(--accent-primary);
    background: var(--bg-secondary);
    box-shadow: inset 0 -2px 0 var(--accent-primary);
}

.sidebar-content {
    flex: 1;
    padding: var(--space-4);
    overflow-y: auto;
}

.tab-content {
    display: none;
}

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

.tab-content h4 {
    font-size: var(--text-sm);
    font-weight: 700;
    margin-bottom: var(--space-3);
    color: var(--accent-primary);
}

.tab-content p {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.7;
}

.tech-item {
    display: flex;
    justify-content: space-between;
    padding: var(--space-2);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-2);
    font-size: var(--text-xs);
}

.tech-label {
    color: var(--text-secondary);
}

.tech-value {
    font-family: var(--font-mono);
    color: var(--accent-success);
}

/* =====================================================
   Timeline Controls
   ===================================================== */
.timeline-controls {
    height: var(--timeline-height);
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border-top: 1px solid var(--glass-border);
    padding: var(--space-4) var(--space-6);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.timeline-bar {
    position: relative;
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    cursor: pointer;
    overflow: hidden;
}

.timeline-progress {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    width: 0%;
    transition: width var(--transition-base);
}

.timeline-markers {
    position: absolute;
    inset: 0;
    display: flex;
    justify-content: space-between;
    padding: 0 2px;
}

.timeline-marker {
    width: 4px;
    height: 100%;
    background: var(--glass-border);
    border-radius: var(--radius-full);
}

.timeline-marker.passed {
    background: var(--accent-success);
}

.timeline-marker.current {
    background: var(--accent-primary);
    box-shadow: 0 0 8px var(--accent-primary);
}

.controls-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.control-group {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.control-group.center {
    flex-direction: column;
    gap: var(--space-1);
}

.phase-indicator {
    font-size: var(--text-lg);
    font-weight: 700;
    font-family: var(--font-mono);
}

.step-label {
    font-size: var(--text-xs);
    color: var(--text-secondary);
}

.speed-control {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-secondary);
}

#speed-slider {
    width: 80px;
    accent-color: var(--accent-primary);
}

#speed-value {
    font-family: var(--font-mono);
    color: var(--text-primary);
    min-width: 30px;
}

/* =====================================================
   Modal
   ===================================================== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal.hidden {
    display: none;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    width: 90%;
    max-width: 480px;
    background: var(--bg-elevated);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--glass-border);
}

.modal-header h3 {
    font-size: var(--text-lg);
    font-weight: 700;
}

.modal-body {
    padding: var(--space-6);
}

.setting-group {
    margin-bottom: var(--space-5);
}

.setting-group label {
    display: block;
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-2);
}

.radio-group {
    display: flex;
    gap: var(--space-4);
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 400;
    cursor: pointer;
}

.toggle {
    width: 44px;
    height: 24px;
    appearance: none;
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
    position: relative;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.toggle::before {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: transform var(--transition-fast);
}

.toggle:checked {
    background: var(--accent-primary);
}

.toggle:checked::before {
    transform: translateX(20px);
}

/* =====================================================
   Utility Classes
   ===================================================== */
.hidden {
    display: none !important;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* =====================================================
   Animations
   ===================================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }

    100% {
        background-position: 200% 0;
    }
}

/* =====================================================
   Responsive Design
   ===================================================== */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .osi-sidebar,
    .info-sidebar {
        display: none;
    }

    :root {
        --sidebar-width: 0;
    }
}

@media (max-width: 768px) {
    .header {
        padding: 0 var(--space-4);
    }

    .url-display {
        display: none;
    }

    .timeline-controls {
        padding: var(--space-3) var(--space-4);
    }

    .control-group.right .speed-control {
        display: none;
    }
}

@media (max-width: 480px) {
    :root {
        --header-height: 50px;
        --timeline-height: 80px;
    }

    .logo-text {
        display: none;
    }

    .btn-control {
        width: 32px;
        height: 32px;
    }

    .btn-play {
        width: 48px;
        height: 48px;
    }
}

/* =====================================================
   Scrollbar Styling
   ===================================================== */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}

/* =====================================================
   URL Input Container
   ===================================================== */
.header-center {
    flex: 1;
    display: flex;
    justify-content: center;
    padding: 0 var(--space-4);
}

.url-input-container {
    display: flex;
    align-items: center;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    padding: var(--space-1) var(--space-1) var(--space-1) var(--space-4);
    transition: all var(--transition-base);
    max-width: 500px;
    width: 100%;
}

.url-input-container:focus-within {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.url-prefix {
    color: var(--accent-success);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 500;
}

.url-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    padding: var(--space-2) var(--space-2);
    min-width: 150px;
}

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

.btn-go {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--gradient-primary);
    border: none;
    border-radius: var(--radius-full);
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-go:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-glow);
}

.btn-go:disabled {
    opacity: 0.7;
    cursor: wait;
}

/* =====================================================
   Notification System
   ===================================================== */
.notification-container {
    position: fixed;
    top: var(--space-6);
    right: var(--space-6);
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    max-width: 400px;
}

.notification {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--bg-elevated);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    transform: translateX(120%);
    transition: all var(--transition-base);
}

.notification.show {
    transform: translateX(0);
}

.notification.hide {
    transform: translateX(120%);
    opacity: 0;
}

.notification-icon {
    font-size: var(--text-lg);
    flex-shrink: 0;
}

.notification-message {
    flex: 1;
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.5;
}

.notification-close {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: var(--text-lg);
    padding: 0;
    line-height: 1;
}

.notification-close:hover {
    color: var(--text-primary);
}

.notification-info {
    border-left: 3px solid var(--accent-info);
}

.notification-success {
    border-left: 3px solid var(--accent-success);
}

.notification-warning {
    border-left: 3px solid var(--accent-warning);
}

.notification-error {
    border-left: 3px solid var(--accent-error);
}

/* =====================================================
   Phase Canvas (for particle effects)
   ===================================================== */
.phase-canvas {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 15;
}

/* =====================================================
   Connection SVG
   ===================================================== */
.connection-svg {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 1;
}

/* DNS Node */
.dns-node {
    position: absolute;
    top: 20%;
    left: 50%;
    transform: translateX(-50%);
}

/* =====================================================
   Phase Detail Panel
   ===================================================== */
.phase-detail-panel {
    position: absolute;
    top: var(--space-4);
    left: var(--space-4);
    width: 320px;
    max-height: 50%;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    z-index: 30;
    transition: all var(--transition-base);
}

.phase-detail-panel.minimized {
    max-height: 44px;
}

.phase-detail-panel.minimized .detail-content {
    display: none;
}

.detail-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-3) var(--space-4);
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--glass-border);
}

.detail-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--accent-primary);
}

.btn-minimize {
    width: 24px;
    height: 24px;
    font-size: var(--text-lg);
    padding: 0;
}

.detail-content {
    padding: var(--space-4);
    max-height: 300px;
    overflow-y: auto;
}

/* =====================================================
   Animation: animate-in
   ===================================================== */
.animate-in {
    animation: slideIn 0.4s ease forwards;
    opacity: 0;
}

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

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* =====================================================
   Phase 1: URL Breakdown
   ===================================================== */
.url-breakdown {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.url-part {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.url-part .part-label {
    font-size: var(--text-xs);
    color: var(--text-muted);
    text-transform: uppercase;
}

.url-part .part-value {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--accent-info);
}

.url-part.scheme .part-value {
    color: var(--accent-success);
}

.url-part.host .part-value {
    color: var(--accent-info);
    font-weight: 600;
}

.url-part.path .part-value {
    color: var(--text-secondary);
}

/* =====================================================
   Phase 2: DNS Chain
   ===================================================== */
.dns-chain {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.dns-step {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.step-icon {
    font-size: var(--text-lg);
}

.step-text {
    flex: 1;
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.step-result {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    font-weight: 600;
}

.step-result.cache-hit {
    background: rgba(16, 185, 129, 0.2);
    color: var(--accent-success);
}

.step-result.cache-miss {
    background: rgba(239, 68, 68, 0.2);
    color: var(--accent-error);
}

.step-result.querying {
    background: rgba(59, 130, 246, 0.2);
    color: var(--accent-info);
}

.step-result.success {
    background: rgba(16, 185, 129, 0.2);
    color: var(--accent-success);
}

.dns-step.result {
    border-left: 3px solid var(--accent-success);
}

.dns-time {
    margin-top: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-muted);
    text-align: right;
}

/* =====================================================
   Phase 3: TCP Handshake
   ===================================================== */
.tcp-handshake {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.handshake-step {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.step-arrow {
    font-size: var(--text-2xl);
    color: var(--accent-primary);
    font-weight: bold;
}

.step-info {
    flex: 1;
}

.step-info .flag {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 700;
    background: var(--layer-4-transport);
    color: white;
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-sm);
    margin-right: var(--space-2);
}

.step-info .detail {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-secondary);
}

.connection-established {
    text-align: center;
    font-weight: 600;
    color: var(--accent-success);
    padding: var(--space-2);
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius-md);
}

/* =====================================================
   Phase 4: TLS Handshake
   ===================================================== */
.tls-handshake {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.tls-step {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--layer-6-presentation);
}

.tls-step .step-name {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-primary);
}

.tls-step .step-detail {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
}

.tls-secure {
    text-align: center;
    font-weight: 600;
    color: var(--accent-success);
    padding: var(--space-2);
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius-md);
}

/* =====================================================
   Phase 5: HTTP Request
   ===================================================== */
.http-request,
.http-response {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
}

.http-line,
.status-line {
    font-weight: 700;
    color: var(--accent-success);
    padding: var(--space-2);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-2);
}

.http-headers,
.response-headers {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    margin-bottom: var(--space-2);
}

.header {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-1) 0;
    border-bottom: 1px solid var(--glass-border);
}

.header-name {
    color: var(--accent-info);
    min-width: 80px;
}

.header-value {
    color: var(--text-secondary);
    word-break: break-all;
}

.encryption-indicator {
    text-align: center;
    color: var(--accent-warning);
    padding: var(--space-2);
    background: rgba(245, 158, 11, 0.1);
    border-radius: var(--radius-md);
}

.body-preview {
    padding: var(--space-2);
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* =====================================================
   Phase 6: IP Packet
   ===================================================== */
.ip-packet {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.packet-diagram {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.packet-layer {
    padding: var(--space-3);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--layer-3-network);
}

.packet-layer.ip {
    background: rgba(34, 197, 94, 0.1);
    border-color: var(--layer-3-network);
}

.packet-layer.tcp {
    background: rgba(59, 130, 246, 0.1);
    border-color: var(--layer-4-transport);
}

.packet-layer.payload {
    background: rgba(168, 85, 247, 0.1);
    border-color: var(--layer-7-application);
}

.layer-title {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.layer-content {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
}

.layer-content .field {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-1) 0;
}

.layer-content .field span:first-child {
    color: var(--text-muted);
    min-width: 60px;
}

.layer-content.hex {
    color: var(--text-muted);
    font-style: italic;
}

/* =====================================================
   Phase 7: ARP & Ethernet
   ===================================================== */
.arp-ethernet {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.arp-section h5,
.ethernet-frame h5 {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.arp-message {
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    margin-bottom: var(--space-1);
}

.arp-message.broadcast {
    border-left: 3px solid var(--accent-warning);
}

.arp-message.reply {
    border-left: 3px solid var(--accent-success);
}

.frame-fields {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
}

.frame-fields .field {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-1) 0;
}

.frame-fields .field span:first-child {
    color: var(--text-muted);
}

/* =====================================================
   Phase 8: Physical Layer
   ===================================================== */
.physical-layer {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.medium-type {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.medium-icon {
    font-size: var(--text-2xl);
}

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

.medium-detail {
    font-size: var(--text-xs);
    color: var(--text-muted);
    margin-left: auto;
}

.signal-visualization {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-4);
}

.wave {
    width: 20px;
    height: 20px;
    border: 2px solid var(--accent-primary);
    border-radius: 50%;
    animation: waveExpand 1.5s ease-out infinite;
}

.wave:nth-child(2) {
    animation-delay: 0.3s;
}

.wave:nth-child(3) {
    animation-delay: 0.6s;
}

@keyframes waveExpand {
    0% {
        transform: scale(0.5);
        opacity: 1;
    }

    100% {
        transform: scale(2);
        opacity: 0;
    }
}

.transmission-info {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
}

.transmission-info .info-item {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-1) 0;
}

.transmission-info .info-item span:first-child {
    color: var(--text-muted);
}

/* =====================================================
   Phase 9: NAT
   ===================================================== */
.nat-processing h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.nat-table {
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.nat-row {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    border-bottom: 1px solid var(--glass-border);
}

.nat-row.header {
    background: var(--bg-elevated);
    font-weight: 700;
    color: var(--text-primary);
}

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

.nat-explanation {
    margin-top: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-muted);
    font-style: italic;
}

/* =====================================================
   Phase 10: BGP Routing
   ===================================================== */
.bgp-routing h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-3);
}

.bgp-path {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-3);
}

.bgp-hop {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.as-number {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--text-primary);
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    border: 1px solid var(--accent-primary);
}

.hop-arrow {
    color: var(--accent-primary);
    font-weight: bold;
}

.route-info {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
}

.route-info .info-item {
    display: flex;
    gap: var(--space-2);
    padding: var(--space-1) 0;
}

.route-info .info-item span:first-child {
    color: var(--text-muted);
}

/* =====================================================
   Server Processing
   ===================================================== */
.server-processing {
    padding: var(--space-2);
}

.server-processing h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.processing-indicator {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--glass-border);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* =====================================================
   Server App
   ===================================================== */
.server-app h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.app-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.app-step {
    padding: var(--space-2);
    font-size: var(--text-xs);
    color: var(--accent-success);
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius-sm);
}

/* =====================================================
   Response Journey
   ===================================================== */
.response-journey h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.journey-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.journey-steps .step {
    padding: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    border-left: 2px solid var(--accent-primary);
}

/* =====================================================
   Client Reception
   ===================================================== */
.client-reception h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.unwrap-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.layer-strip {
    padding: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-secondary);
    background: linear-gradient(90deg, var(--bg-tertiary) 0%, transparent 100%);
    border-radius: var(--radius-sm);
}

/* =====================================================
   Browser Render
   ===================================================== */
.browser-render h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.render-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.render-step {
    display: flex;
    justify-content: space-between;
    padding: var(--space-2);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    font-size: var(--text-xs);
}

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

.render-step .step-output {
    color: var(--accent-success);
}

/* =====================================================
   Connection Maintain
   ===================================================== */
.connection-maintain h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.maintain-info .info-item {
    padding: var(--space-2);
    font-size: var(--text-xs);
    color: var(--text-secondary);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-1);
}

/* =====================================================
   Optimizations
   ===================================================== */
.optimizations h5 {
    font-size: var(--text-sm);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.opt-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.opt-item {
    display: flex;
    justify-content: space-between;
    padding: var(--space-2) var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.opt-name {
    font-size: var(--text-sm);
    color: var(--text-primary);
}

.opt-impact {
    font-size: var(--text-xs);
    color: var(--accent-success);
    font-weight: 600;
}

.complete-message {
    text-align: center;
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--accent-success);
    padding: var(--space-4);
    background: rgba(16, 185, 129, 0.1);
    border-radius: var(--radius-md);
    margin-top: var(--space-3);
}

/* =====================================================
   Live Data
   ===================================================== */
.live-data-grid {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.data-group {
    padding: var(--space-3);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.data-group h5 {
    font-size: var(--text-xs);
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: var(--space-2);
    text-transform: uppercase;
}

.data-item {
    display: flex;
    justify-content: space-between;
    font-size: var(--text-xs);
    padding: var(--space-1) 0;
    border-bottom: 1px solid var(--glass-border);
}

.data-item:last-child {
    border-bottom: none;
}

.data-item span:first-child {
    color: var(--text-muted);
}

.data-item span:last-child {
    font-family: var(--font-mono);
    color: var(--text-primary);
}

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