/* CSS Variables */
:root {
    --bg-primary: #0f0f1a;
    --bg-secondary: #1a1a2e;
    --bg-card: #16213e;
    --accent-primary: #00d9ff;
    --accent-secondary: #7b2cbf;
    --accent-gradient: linear-gradient(135deg, #00d9ff 0%, #7b2cbf 100%);
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --success: #00ff88;
    --warning: #ffaa00;
    --danger: #ff4466;
    --border-radius: 12px;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --glow: 0 0 20px rgba(0, 217, 255, 0.3);
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    font-family: 'Segoe UI', 'Microsoft JhengHei', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Container */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100%;
    display: flex;
    flex-direction: column;
}

/* Back Button */
.back-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s;
    margin-bottom: 10px;
    width: fit-content;
}

.back-btn:hover {
    background: var(--bg-card);
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

/* Header */
header {
    text-align: center;
    padding: 20px 0 15px;
    flex-shrink: 0;
}

header h1 {
    font-size: 2rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 6px;
}

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

/* Tabs Navigation */
.tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    flex-shrink: 0;
}

.tab-btn {
    flex: 1;
    min-width: 100px;
    padding: 14px 16px;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 10px 10px 0 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

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

.tab-btn.active {
    background: var(--bg-card);
    color: var(--accent-primary);
    border-bottom-color: var(--bg-card);
    box-shadow: 0 -2px 10px rgba(0, 217, 255, 0.2);
}

/* Tab Content */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-height: 0;
}

.tab-content {
    display: none;
    flex: 1;
    min-height: 0;
}

.tab-content.active {
    display: flex;
    flex-direction: column;
}

/* Cards */
.card {
    background: var(--bg-card);
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-top: none;
}

.card-comm {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card h2 {
    font-size: 1.2rem;
    margin-bottom: 16px;
    color: var(--accent-primary);
}

/* Form Elements */
.form-row {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
    flex-wrap: wrap;
    align-items: flex-start;
}

.form-group {
    flex: 1;
    min-width: 120px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

input, select, textarea {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 0.95rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 217, 255, 0.1);
}

textarea {
    resize: vertical;
    font-family: 'Consolas', 'Monaco', monospace;
}

/* Radio Group */
.radio-group {
    display: flex;
    gap: 16px;
    padding-top: 4px;
}

.radio-group label {
    display: flex;
    align-items: center;
    gap: 4px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 0.9rem;
    margin-bottom: 0;
}

.radio-group input[type="radio"] {
    width: auto;
    accent-color: var(--accent-primary);
}

/* Buttons */
.btn-group {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

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

.btn-primary:hover {
    transform: scale(1.02);
    box-shadow: var(--glow);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

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

.btn-small {
    padding: 6px 12px;
    font-size: 0.85rem;
}

/* Connection Status */
.connection-status {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border-radius: 8px;
    flex-wrap: wrap;
}

.local-ip {
    margin-left: auto;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.local-ip span {
    color: var(--accent-primary);
}

/* HTTPS Warning */
.https-warning {
    margin-top: 12px;
    padding: 12px 16px;
    background: rgba(255, 170, 0, 0.15);
    border: 1px solid var(--warning);
    border-radius: 8px;
    color: var(--warning);
    font-size: 0.9rem;
}

.https-warning a {
    color: var(--accent-primary);
    text-decoration: underline;
    cursor: pointer;
}

.status-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--text-secondary);
    transition: background 0.3s;
}

.status-dot.connected {
    background: var(--success);
    box-shadow: 0 0 10px var(--success);
}

.status-dot.error {
    background: var(--danger);
    box-shadow: 0 0 10px var(--danger);
}

.status-dot.connecting {
    background: var(--warning);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Log Section */
.log-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    margin-top: 20px;
    min-height: 200px;
}

.log-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.log-header h3 {
    font-size: 1rem;
    color: var(--accent-primary);
}

.log-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.log-controls label {
    color: var(--text-secondary);
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 4px;
}

.log-container {
    background: var(--bg-primary);
    border-radius: 8px;
    padding: 12px;
    flex: 1;
    min-height: 150px;
    max-height: 300px;
    overflow-y: auto;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.85rem;
}

.log-placeholder {
    color: var(--text-secondary);
    text-align: center;
    padding: 30px;
}

.log-entry {
    padding: 6px 10px;
    margin-bottom: 6px;
    border-radius: 6px;
    border-left: 3px solid;
}

.log-entry.sent {
    background: rgba(0, 217, 255, 0.1);
    border-color: var(--accent-primary);
}

.log-entry.received {
    background: rgba(0, 255, 136, 0.1);
    border-color: var(--success);
}

.log-entry.error {
    background: rgba(255, 68, 102, 0.1);
    border-color: var(--danger);
}

.log-entry.info {
    background: rgba(255, 170, 0, 0.1);
    border-color: var(--warning);
}

.log-time {
    color: var(--text-secondary);
    font-size: 0.75rem;
    margin-right: 8px;
}

.log-label {
    font-weight: 600;
    margin-right: 6px;
}

.log-latency {
    color: var(--warning);
    font-size: 0.75rem;
    margin-left: 8px;
}

/* Quick Commands */
.quick-commands {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.cmd-btn {
    padding: 14px 22px;
    background: var(--bg-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.cmd-btn:hover {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.05);
}

.hint {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 16px;
}

/* Footer */
footer {
    text-align: center;
    padding: 15px 0;
    color: var(--text-secondary);
    font-size: 0.85rem;
    flex-shrink: 0;
}

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

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 3px;
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 1.5rem;
    }
    
    .tabs {
        gap: 4px;
    }
    
    .tab-btn {
        min-width: calc(33% - 4px);
        padding: 12px 8px;
        font-size: 0.8rem;
    }
    
    .form-row {
        flex-direction: column;
    }
    
    .form-group {
        min-width: 100%;
    }
    
    .btn-group {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .card {
        padding: 16px;
    }
    
    .quick-commands {
        gap: 8px;
    }
    
    .cmd-btn {
        padding: 12px 16px;
        font-size: 0.9rem;
    }
}