:root {
    --primary-color: #10b981;
    --primary-hover: #059669;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --secondary-color: #6b7280;
    --secondary-hover: #4b5563;
    --bg-color: #f0fdf4;
    --card-bg: #ffffff;
    --border-color: #d1d5db;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --radius: 8px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 24px;
}

h1 {
    font-size: 28px;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 16px;
}

.tab-nav {
    display: flex;
    justify-content: center;
    gap: 8px;
}

.tab-btn {
    padding: 10px 24px;
    border: 2px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius);
    transition: all 0.2s ease;
}

.tab-btn:hover {
    background: rgba(16, 185, 129, 0.1);
}

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

.tab-content {
    display: none;
}

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

.panel {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 16px;
    overflow: hidden;
}

.panel-header {
    background: linear-gradient(135deg, #10b981 0%, #34d399 100%);
    padding: 12px 16px;
}

.panel-header h2 {
    color: white;
    font-size: 16px;
    font-weight: 500;
    margin: 0;
}

.panel-body {
    padding: 16px;
}

.form-group {
    margin-bottom: 16px;
}

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

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
    margin-bottom: 8px;
}

.input-row {
    display: flex;
    gap: 8px;
}

.input-row input {
    flex: 1;
}

input[type="text"],
textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 14px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input[type="text"]:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.15);
}

textarea {
    min-height: 100px;
    resize: vertical;
    font-family: "Consolas", "Monaco", monospace;
}

.btn {
    padding: 10px 16px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
}

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

.btn-danger:hover:not(:disabled) {
    background: var(--danger-hover);
}

.btn-secondary {
    background: #e5e7eb;
    color: var(--text-color);
}

.btn-secondary:hover:not(:disabled) {
    background: #d1d5db;
}

.btn-small {
    padding: 6px 12px;
    font-size: 13px;
}

.btn-icon {
    width: 32px;
    height: 32px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    background: #fee2e2;
    color: var(--danger-color);
}

.btn-icon:hover {
    background: #fecaca;
}

.btn-row {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.status-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    background: #f9fafb;
    border-radius: var(--radius);
}

.status-label {
    font-size: 14px;
    color: var(--text-light);
}

.status-text {
    font-size: 14px;
    font-weight: 500;
}

.status-text.connected {
    color: var(--success-color);
}

.status-text.disconnected {
    color: var(--danger-color);
}

.status-text.connecting {
    color: var(--warning-color);
}

.notice-box {
    padding: 12px 16px;
    background: #fef3c7;
    border: 1px solid #f59e0b;
    border-radius: var(--radius);
    margin-bottom: 16px;
}

.notice-box p {
    margin: 0 0 4px 0;
    font-size: 14px;
    color: #92400e;
}

.notice-box p:last-child {
    margin-bottom: 0;
}

.message-box {
    min-height: 200px;
    max-height: 400px;
    overflow-y: auto;
    padding: 12px;
    background: #f9fafb;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-family: "Consolas", "Monaco", monospace;
    font-size: 13px;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-all;
}

.message-item {
    padding: 8px 12px;
    margin-bottom: 8px;
    border-radius: 6px;
    background: white;
    border-left: 3px solid var(--primary-color);
}

.message-item.sent {
    border-left-color: var(--warning-color);
}

.message-item.received {
    border-left-color: var(--primary-color);
}

.message-item.system {
    border-left-color: var(--secondary-color);
    background: #f3f4f6;
}

.message-time {
    font-size: 11px;
    color: var(--text-light);
    margin-bottom: 4px;
}

.message-content {
    color: var(--text-color);
}

#headers-container {
    margin-bottom: 8px;
}

.header-row {
    display: flex;
    gap: 8px;
    margin-bottom: 8px;
}

.header-row input {
    flex: 1;
}

@media (max-width: 600px) {
    .container {
        padding: 12px;
    }

    h1 {
        font-size: 22px;
    }

    .input-row {
        flex-direction: column;
    }

    .input-row .btn {
        width: 100%;
    }

    .btn-row {
        flex-wrap: wrap;
    }

    .btn-row .btn {
        flex: 1;
        min-width: 80px;
    }
}