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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 450px;
}

.phone-container {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

h1 {
    text-align: center;
    padding: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    margin: 0;
}

.screen {
    padding: 30px;
}

.screen.hidden {
    display: none;
}

/* Login Screen */
.login-form {
    max-width: 300px;
    margin: 0 auto;
}

.login-form h2 {
    text-align: center;
    margin-bottom: 30px;
    color: #333;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
}

.status {
    margin-top: 15px;
    padding: 10px;
    border-radius: 5px;
    text-align: center;
    font-size: 14px;
}

.status.error {
    background: #fee;
    color: #c33;
}

.status.success {
    background: #efe;
    color: #3c3;
}

/* Phone Screen */
.phone-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: #f5f5f5;
    border-bottom: 1px solid #e0e0e0;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #ccc;
}

.status-dot.connected {
    background: #4caf50;
    animation: pulse 2s infinite;
}

.status-dot.ringing {
    background: #ff9800;
    animation: pulse 1s infinite;
}

.status-dot.in-call {
    background: #2196f3;
}

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

.user-info {
    font-weight: 600;
    color: #333;
}

.call-display {
    padding: 20px;
    text-align: center;
    min-height: 100px;
}

.call-status {
    font-size: 18px;
    color: #666;
    margin-bottom: 10px;
}

.caller-info {
    font-size: 24px;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.call-duration {
    font-size: 16px;
    color: #999;
}

.dialpad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    padding: 20px;
}

.dial-btn {
    padding: 20px;
    font-size: 20px;
    font-weight: 600;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    background: white;
    cursor: pointer;
    transition: all 0.2s;
    color: #333;
}

.dial-btn:hover {
    background: #f5f5f5;
    border-color: #667eea;
}

.dial-btn:active {
    transform: scale(0.95);
    background: #667eea;
    color: white;
}

.number-display {
    padding: 0 20px 20px;
    display: flex;
    gap: 10px;
}

#numberInput {
    flex: 1;
    padding: 15px;
    font-size: 20px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    text-align: center;
}

.call-controls {
    padding: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-call {
    background: #4caf50;
    color: white;
    flex: 1;
    font-size: 18px;
}

.btn-call:hover {
    background: #45a049;
}

.btn-hangup {
    background: #f44336;
    color: white;
    flex: 1;
    font-size: 18px;
}

.btn-hangup:hover {
    background: #da190b;
}

.btn-answer {
    background: #4caf50;
    color: white;
    flex: 1;
}

.btn-reject {
    background: #f44336;
    color: white;
    flex: 1;
}

.btn-small {
    padding: 8px 15px;
    font-size: 14px;
    background: #666;
    color: white;
}

.btn-small:hover {
    background: #555;
}

.hidden {
    display: none !important;
}

.volume-controls {
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.volume-controls label {
    font-weight: 500;
    color: #555;
}

#volumeSlider {
    flex: 1;
}

#volumeValue {
    min-width: 50px;
    text-align: right;
    color: #666;
}