/* CSS Variables for theming */
:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #10b981;
    --background-color: #0f172a;
    --surface-color: #1e293b;
    --surface-hover: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    --error-color: #ef4444;
    --success-color: #22c55e;
    --highlight-color: rgba(99, 102, 241, 0.3);
    --highlight-border: #6366f1;
    --match-color-1: rgba(99, 102, 241, 0.4);
    --match-color-2: rgba(16, 185, 129, 0.4);
    --match-color-3: rgba(245, 158, 11, 0.4);
    --match-color-4: rgba(236, 72, 153, 0.4);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4);
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

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

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

/* Header */
.header {
    text-align: center;
    padding: 2rem 1rem;
    margin-bottom: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
}

.logo-img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.header h1 {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Section Styles */
section {
    background-color: var(--surface-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    box-shadow: var(--shadow-md);
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.section-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Regex Input Section */
.regex-input-container {
    display: flex;
    align-items: center;
    background-color: var(--background-color);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    transition: border-color var(--transition-fast);
}

.regex-input-container:focus-within {
    border-color: var(--primary-color);
}

.regex-delimiter {
    color: var(--primary-color);
    font-size: 1.25rem;
    font-weight: 600;
    padding: 0 0.25rem;
    font-family: 'Consolas', 'Monaco', monospace;
}

.regex-input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: 'Consolas', 'Monaco', monospace;
    padding: 0.5rem;
    outline: none;
    min-width: 0;
}

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

.flags-input {
    width: 60px;
    background: transparent;
    border: none;
    border-left: 1px solid var(--border-color);
    color: var(--secondary-color);
    font-size: 1rem;
    font-family: 'Consolas', 'Monaco', monospace;
    padding: 0.5rem;
    outline: none;
    text-align: center;
}

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

/* Flags Toggles */
.flags-toggles {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
    flex-wrap: wrap;
}

.flag-toggle {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.5rem 0.75rem;
    background-color: var(--background-color);
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast);
}

.flag-toggle:hover {
    background-color: var(--surface-hover);
}

.flag-toggle input[type="checkbox"] {
    display: none;
}

.flag-toggle input[type="checkbox"]:checked + .flag-label {
    background-color: var(--primary-color);
    color: white;
}

.flag-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background-color: var(--surface-hover);
    border-radius: var(--radius-sm);
    font-family: 'Consolas', 'Monaco', monospace;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.flag-desc {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Error Message */
.error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: 0.75rem;
    padding: 0.5rem 0.75rem;
    background-color: rgba(239, 68, 68, 0.1);
    border-radius: var(--radius-sm);
    display: none;
}

.error-message.visible {
    display: block;
}

/* Test String Section */
.test-input-container {
    position: relative;
    min-height: 150px;
}

.test-input,
.highlighted-text {
    width: 100%;
    min-height: 150px;
    font-size: 1rem;
    font-family: 'Consolas', 'Monaco', monospace;
    line-height: 1.6;
    padding: 1rem;
    border-radius: var(--radius-md);
    white-space: pre-wrap;
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.test-input {
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-primary);
    resize: vertical;
    outline: none;
    position: relative;
    z-index: 2;
    caret-color: var(--text-primary);
    transition: border-color var(--transition-fast);
}

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

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

.highlighted-text {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--background-color);
    border: 2px solid transparent;
    color: transparent;
    pointer-events: none;
    z-index: 1;
    overflow: hidden;
}

.highlighted-text .match {
    background-color: var(--match-color-1);
    border-bottom: 2px solid var(--primary-color);
    border-radius: 2px;
}

.highlighted-text .match:nth-of-type(4n+2) {
    background-color: var(--match-color-2);
    border-bottom-color: var(--secondary-color);
}

.highlighted-text .match:nth-of-type(4n+3) {
    background-color: var(--match-color-3);
    border-bottom-color: #f59e0b;
}

.highlighted-text .match:nth-of-type(4n+4) {
    background-color: var(--match-color-4);
    border-bottom-color: #ec4899;
}

/* Match Count Badge */
.match-count {
    font-size: 0.875rem;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 9999px;
    font-weight: 600;
}

.match-count:empty {
    display: none;
}

/* Results Section */
.results-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.tab-btn {
    padding: 0.5rem 1rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

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

.tab-btn.active {
    color: var(--primary-color);
    background-color: rgba(99, 102, 241, 0.1);
}

.tab-content {
    display: none;
}

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

.matches-list,
.groups-list {
    max-height: 300px;
    overflow-y: auto;
}

.placeholder-text {
    color: var(--text-muted);
    text-align: center;
    padding: 2rem;
    font-style: italic;
}

/* Match Item */
.match-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 0.75rem;
    background-color: var(--background-color);
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
}

.match-index {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    background-color: var(--primary-color);
    color: white;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
}

.match-details {
    flex: 1;
    min-width: 0;
}

.match-value {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.95rem;
    color: var(--text-primary);
    word-break: break-all;
    background-color: var(--surface-hover);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    display: inline-block;
}

.match-position {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Group Item */
.group-item {
    padding: 0.75rem;
    background-color: var(--background-color);
    border-radius: var(--radius-sm);
    margin-bottom: 0.5rem;
}

.group-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.group-name {
    font-weight: 600;
    color: var(--secondary-color);
    font-family: 'Consolas', 'Monaco', monospace;
}

.group-values {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.group-value {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.875rem;
    color: var(--text-primary);
    background-color: var(--surface-hover);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
}

.group-value.empty {
    color: var(--text-muted);
    font-style: italic;
}

/* Patterns Library */
.patterns-section .section-header {
    cursor: pointer;
}

.toggle-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.25rem;
    transition: transform var(--transition-fast);
}

.toggle-btn.rotated .toggle-icon {
    transform: rotate(180deg);
}

.toggle-icon {
    display: inline-block;
    transition: transform var(--transition-fast);
}

.patterns-library {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.patterns-library.expanded {
    max-height: 1000px;
}

.patterns-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 0.75rem;
    padding-top: 0.5rem;
}

.pattern-card {
    background-color: var(--background-color);
    border-radius: var(--radius-sm);
    padding: 0.75rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.pattern-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

.pattern-name {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    font-size: 0.9rem;
}

.pattern-regex {
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.8rem;
    color: var(--primary-color);
    word-break: break-all;
    background-color: var(--surface-color);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
}

.pattern-description {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Footer */
.footer {
    text-align: center;
    padding: 1.5rem;
    margin-top: 2rem;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-color);
    border-radius: 4px;
}

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

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .app-container {
        padding: 0.75rem;
    }

    .header {
        padding: 1.5rem 0.5rem;
    }

    .header h1 {
        font-size: 1.5rem;
    }

    .tagline {
        font-size: 0.875rem;
    }

    section {
        padding: 1rem;
    }

    .regex-input-container {
        flex-wrap: wrap;
    }

    .regex-input {
        order: 1;
        flex: 1 1 100%;
        min-width: 100%;
        border-bottom: 1px solid var(--border-color);
        padding: 0.75rem 0.5rem;
    }

    .regex-delimiter:first-of-type {
        order: 0;
        display: none;
    }

    .regex-delimiter:nth-of-type(2) {
        order: 2;
        display: none;
    }

    .flags-input {
        order: 3;
        width: 100%;
        border-left: none;
        text-align: left;
        padding: 0.5rem;
    }

    .flags-toggles {
        gap: 0.5rem;
    }

    .flag-toggle {
        padding: 0.4rem 0.6rem;
    }

    .flag-desc {
        font-size: 0.75rem;
    }

    .test-input,
    .highlighted-text {
        min-height: 120px;
        font-size: 0.9rem;
    }

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

    .match-item {
        flex-direction: column;
        gap: 0.5rem;
    }

    .results-tabs {
        flex-wrap: wrap;
    }

    .tab-btn {
        flex: 1;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.25rem;
    }

    .logo-img {
        width: 32px;
        height: 32px;
    }

    .section-header h2 {
        font-size: 0.875rem;
    }

    .test-input,
    .highlighted-text {
        min-height: 100px;
        padding: 0.75rem;
    }

    .match-count {
        font-size: 0.75rem;
        padding: 0.2rem 0.5rem;
    }
}

/* Animation for new matches */
@keyframes highlightPulse {
    0% {
        opacity: 0.5;
    }
    50% {
        opacity: 1;
    }
    100% {
        opacity: 0.5;
    }
}

.match-item.new {
    animation: highlightPulse 0.5s ease;
}