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

:root {
    --bg-color: #030305;
    --bg-secondary: #0a0a0f;
    --bg-tertiary: #12121a;
    --text-main: #ffffff;
    --text-muted: #9494a8;
    --primary: #00eaff;
    --secondary: #ff00c8;
    --accent: #7000ff;
    --success: #00ff88;
    --error: #ff4757;
    --warning: #ffa502;
    --glass-bg: rgba(20, 20, 25, 0.6);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

body {
    font-family: 'Outfit', sans-serif;
    background: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 30px 20px;
    background: var(--glass-bg);
    border-radius: var(--card-radius);
    border: 1px solid var(--glass-border);
    position: relative;
}

.back-link {
    position: absolute;
    top: 20px;
    left: 20px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
}

.back-link:hover {
    color: var(--primary);
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header h1 i {
    margin-right: 12px;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Panels */
.panel {
    background: var(--glass-bg);
    border-radius: var(--card-radius);
    border: 1px solid var(--glass-border);
    padding: 20px;
    margin-bottom: 20px;
    transition: var(--transition);
}

.panel:hover {
    border-color: rgba(255, 255, 255, 0.15);
}

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.panel-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Flags */
.flags {
    display: flex;
    gap: 8px;
}

.flag-btn {
    cursor: pointer;
}

.flag-btn input {
    display: none;
}

.flag-btn span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    transition: var(--transition);
}

.flag-btn input:checked + span {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-color: transparent;
    color: #000;
}

.flag-btn:hover span {
    border-color: var(--primary);
}

/* Regex Input */
.regex-input-wrapper {
    display: flex;
    align-items: center;
    background: var(--bg-tertiary);
    border: 2px solid var(--glass-border);
    border-radius: 12px;
    padding: 12px 16px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    transition: var(--transition);
}

.regex-input-wrapper:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 20px rgba(0, 234, 255, 0.15);
}

.delimiter {
    color: var(--primary);
    font-weight: 600;
    margin-right: 8px;
}

.regex-input-wrapper .delimiter:last-of-type {
    margin-right: 4px;
    margin-left: 8px;
}

#flags-display {
    color: var(--secondary);
    font-weight: 600;
}

#regex-input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-main);
    font-family: inherit;
    font-size: inherit;
}

#regex-input::placeholder {
    color: var(--text-muted);
    opacity: 0.5;
}

.error-message {
    color: var(--error);
    font-size: 0.85rem;
    margin-top: 10px;
    display: none;
}

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

/* Panels Row */
.panels-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 900px) {
    .panels-row {
        grid-template-columns: 1fr;
    }
}

/* Text Input */
#test-input {
    width: 100%;
    min-height: 200px;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    padding: 15px;
    color: var(--text-main);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    resize: vertical;
    outline: none;
    transition: var(--transition);
}

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

#test-input::placeholder {
    color: var(--text-muted);
    opacity: 0.5;
}

/* Icon Button */
.icon-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    padding: 8px 12px;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
}

.icon-btn:hover {
    border-color: var(--error);
    color: var(--error);
}

/* Badge */
.badge {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #000;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Result Output */
.result-output {
    background: var(--bg-tertiary);
    border-radius: 12px;
    padding: 15px;
    min-height: 200px;
    max-height: 300px;
    overflow-y: auto;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
}

.placeholder {
    color: var(--text-muted);
    opacity: 0.5;
    text-align: center;
    padding: 40px;
}

.match-item {
    display: inline-flex;
    align-items: center;
    background: rgba(0, 234, 255, 0.15);
    border: 1px solid rgba(0, 234, 255, 0.3);
    border-radius: 6px;
    padding: 6px 12px;
    margin: 4px;
    font-size: 0.85rem;
    transition: var(--transition);
}

.match-item:hover {
    background: rgba(0, 234, 255, 0.25);
    border-color: var(--primary);
}

.match-index {
    color: var(--text-muted);
    font-size: 0.7rem;
    margin-right: 8px;
    opacity: 0.7;
}

.match-value {
    color: var(--primary);
    font-weight: 500;
}

/* Groups Output */
.groups-output {
    background: var(--bg-tertiary);
    border-radius: 12px;
    padding: 15px;
    min-height: 80px;
}

.group-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 15px;
    background: var(--bg-secondary);
    border-radius: 8px;
    margin-bottom: 8px;
    border-left: 3px solid var(--accent);
}

.group-item:last-child {
    margin-bottom: 0;
}

.group-name {
    color: var(--secondary);
    font-family: 'JetBrains Mono', monospace;
    font-weight: 600;
    min-width: 60px;
}

.group-value {
    color: var(--text-main);
    font-family: 'JetBrains Mono', monospace;
}

/* Reference Grid */
.reference-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 10px;
}

.ref-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    transition: var(--transition);
}

.ref-item:hover {
    background: var(--bg-secondary);
    transform: translateX(4px);
}

.ref-item code {
    background: linear-gradient(135deg, rgba(0, 234, 255, 0.2), rgba(112, 0, 255, 0.2));
    padding: 4px 8px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--primary);
}

.ref-item span {
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* Highlighted text */
.highlight {
    background: rgba(0, 234, 255, 0.3);
    border-bottom: 2px solid var(--primary);
    border-radius: 2px;
}

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

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

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

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.15);
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 20px;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 15px;
    }

    header h1 {
        font-size: 1.8rem;
    }

    .regex-input-wrapper {
        font-size: 1rem;
        padding: 10px 12px;
    }

    .reference-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}