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

:root {
    --primary-color: #4CAF50;
    --primary-dark: #388E3C;
    --danger-color: #f44336;
    --danger-dark: #d32f2f;
    --bg-color: #121212;
    --surface-color: #1e1e1e;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

#app {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.screen {
    display: none;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 20px;
}

.screen.active {
    display: flex;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: 2px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.input-group {
    display: flex;
    gap: 10px;
    width: 100%;
    max-width: 280px;
}

input[type="text"] {
    flex: 1;
    padding: 16px 20px;
    font-size: 1.5rem;
    text-align: center;
    letter-spacing: 8px;
    border: 2px solid var(--surface-color);
    border-radius: 12px;
    background-color: var(--surface-color);
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.2s;
}

input[type="text"]:focus {
    border-color: var(--primary-color);
}

input[type="text"]::placeholder {
    letter-spacing: 0;
    font-size: 1rem;
    color: var(--text-secondary);
}

.btn-primary {
    padding: 16px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 12px;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.btn-secondary {
    padding: 12px 24px;
    font-size: 1rem;
    border: 2px solid var(--text-secondary);
    border-radius: 12px;
    background-color: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-secondary:hover {
    border-color: var(--text-primary);
    color: var(--text-primary);
}

.hint {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Spinner */
.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--surface-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.status {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.password-display {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    letter-spacing: 4px;
}

/* Connected Screen */
.call-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--primary-color);
    animation: pulse 2s ease-in-out infinite;
}

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

.fingerprints {
    background-color: var(--surface-color);
    padding: 20px;
    border-radius: 16px;
    width: 100%;
}

.fingerprint-section {
    margin-bottom: 15px;
}

.fingerprint-section .label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.fingerprint-section .icons {
    font-size: 1.5rem;
    letter-spacing: 6px;
}

.fingerprint-hint {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px solid #333;
}

.call-controls {
    display: flex;
    justify-content: space-around;
    align-items: center;
    width: 100%;
    margin-top: 20px;
    padding: 0 20px;
}

.btn-control {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 16px 24px;
    border: none;
    border-radius: 16px;
    background-color: var(--surface-color);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-control:hover {
    background-color: #2a2a2a;
}

.btn-control .icon {
    font-size: 1.5rem;
}

.btn-control .label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

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

.btn-control.muted .label {
    color: white;
}

.btn-hangup {
    width: 70px;
    height: 70px;
    border: none;
    border-radius: 50%;
    background-color: var(--danger-color);
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    transition: background-color 0.2s;
    transform: rotate(135deg);
}

.btn-hangup:hover {
    background-color: var(--danger-dark);
}

/* Error Screen */
.error-icon {
    font-size: 4rem;
}

.error-text {
    color: var(--danger-color);
    font-size: 1.1rem;
    max-width: 280px;
}

/* Mobile Optimizations */
@media (max-width: 480px) {
    #app {
        padding: 15px;
    }

    h1 {
        font-size: 2rem;
    }

    input[type="text"] {
        padding: 14px 16px;
        font-size: 1.3rem;
        letter-spacing: 6px;
    }

    .fingerprint-section .icons {
        font-size: 1.4rem;
        letter-spacing: 4px;
    }
}

/* Small screen (< 400px) */
@media (max-width: 400px) {
    #app {
        padding: 12px;
    }

    h1 {
        font-size: 1.8rem;
        letter-spacing: 1px;
    }

    .subtitle {
        font-size: 0.85rem;
    }

    .input-group {
        max-width: 100%;
        gap: 8px;
    }

    input[type="text"] {
        padding: 12px 10px;
        font-size: 1.2rem;
        letter-spacing: 4px;
        min-width: 0;
    }

    input[type="text"]::placeholder {
        font-size: 0.85rem;
    }

    .btn-primary {
        padding: 12px 16px;
        font-size: 0.9rem;
        white-space: nowrap;
        flex-shrink: 0;
    }

    .hint {
        font-size: 0.8rem;
    }

    .fingerprints {
        padding: 16px 12px;
    }

    .fingerprint-section .label {
        font-size: 0.8rem;
    }

    .fingerprint-section .icons {
        font-size: 1.2rem;
        letter-spacing: 2px;
    }

    .fingerprint-hint {
        font-size: 0.75rem;
    }

    .call-controls {
        padding: 0 10px;
    }

    .btn-control {
        padding: 12px 18px;
    }

    .btn-control .icon {
        font-size: 1.3rem;
    }

    .btn-hangup {
        width: 60px;
        height: 60px;
        font-size: 1.3rem;
    }

    .screen {
        gap: 16px;
    }
}

/* Safe area for notched devices */
@supports (padding: max(0px)) {
    body {
        padding-left: max(15px, env(safe-area-inset-left));
        padding-right: max(15px, env(safe-area-inset-right));
        padding-bottom: max(15px, env(safe-area-inset-bottom));
    }
}